www.epa.gov/radiation May 2017 EPA 402-S17-001 Revision 0 Rapid Radiochemical Method for Curium- 244 in Water Samples for Environmental Remediation Following Radiological Incidents U.S. Environmental Protection Agency Office of Air and Radiation Office of Radiation and Indoor Air National Analytical Radiation Environmental Laboratory Montgomery, AL 36115 Office of Research and Development National Homeland Security Research Center Cincinnati, OH 45268
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wwwepagovradiation May 2017 EPA 402-S17-001 Revision 0
Rapid Radiochemical Method for Curium-244 in Water Samples for Environmental
Remediation Following Radiological Incidents
US Environmental Protection Agency
Office of Air and Radiation Office of Radiation and Indoor Air
National Analytical Radiation Environmental Laboratory Montgomery AL 36115
Office of Research and Development
National Homeland Security Research Center Cincinnati OH 45268
Rapid Radiochemical Method for Curium-244 in Air Particulate Filters Swipes and Soils
Revision History
Revision 0 Original release 05-01-2016
This report was prepared for the National Analytical Radiation Environmental Laboratory of the Office of Radiation and Indoor Air and the National Homeland Security Research Center of the US Environmental Protection Agencyrsquos (EPA) Office of Research and Development It was prepared by Environmental Management Support Inc of Silver Spring Maryland under contract EP-W-13-016 task order 014 managed by Dan Askren This document has been reviewed in accordance with EPA policy and approved for publication Note that approval does not signify that the contents necessarily reflect the views of the Agency Mention of trade names products or services does not convey EPA approval endorsement or recommendation
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 3 Revision 0
RAPID RADIOCHEMICAL METHOD FOR CM-244 IN WATER SAMPLES FOR
ENVIRONMENTAL REMEDIATION FOLLOWING RADIOLOGICAL INCIDENTS
1 Scope and Application
11 This method provides for the rapid determination of 244
Cm in water samples
12 The method uses radiochemical separation techniques to rapidly isolate curium from a
water matrix using 243
Am tracer as a yield monitor
13 A sample test source is prepared by microprecipitation The test source is counted by
alpha spectrometry for 244
Cm
131 Cm-243 emits alpha particles that are isoenergetic with 244
Cm Alpha
spectrometry measurements that show activity in the region of interest for 244
Cm should be reported as 244243
Cm
14 This method is capable of achieving a required method uncertainty for 244
Cm of 20
pCiL at an analytical action level of 15 pCiL To attain the stated measurement
quality objectives (MQOs) a sample volume of approximately 02 L and count time
of at least 4 hours are recommended Sample count times may vary based on
differences in instrument parameters such as detection efficiency and background
15 The 244
Cm method was single-laboratory evaluated following the guidance presented
for Level E Method Validation Adapted or Newly Developed Methods Including
rapid methodsrdquo in Method Validation Guide for Qualifying Methods Used by
Radiological Laboratories Participating in Incident Response Activities (Reference
161) and Chapter 6 of the Multi-Agency Radiological Laboratory Analytical
Protocols Manual (MARLAP Reference 162)
151 Since californium and americium track closely with curium through the
chemical separation it may be possible to determine isotopes of
californium as well as isotopes of americium (eg 241
Am) that may be
present in the sample test source The specific method performance (yield
required method uncertainty [uMR] minimum detectable activity and critical
level) for other isotopes of californium americium or curium (eg 249
Cf 241
Am or 244243
Cm must be validated by the laboratory prior to performing
determinations for these radionuclides)
152 The sample turnaround time and throughput may vary based on additional
project MQOs the time for analysis of the sample test source and initial
sample weight volume
153 The method must be validated prior to use following the protocols provided
in Method Validation Guide for Qualifying Methods Used by Radiological
Laboratories Participating in Incident Response Activities (Reference 161)
2 Summary of Method
21 This method is based on the use of extraction chromatography resins (TEVAreg + DGA
Resins) to isolate and purify curium by removing interfering radionuclides and other
matrix components and prepare the curium fraction for counting by alpha
spectrometry The method utilizes vacuum-assisted flow to improve the speed of the
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 4 Revision 0
separations An 243
Am tracer is equilibrated with the water sample and used as a yield
monitor Following chemical separation of Cm and Am the sample test source (STS)
is prepared by microprecipitation with cerium fluoride (CeF3) The alpha emissions
from the source are measured using an alpha spectrometer and used to calculate the
activity of 244
Cm in the sample
3 Definitions Abbreviations and Acronyms
31 Analytical Protocol Specifications (APS) The output of a directed planning process
that contains the projectrsquos analytical data needs and requirements in an organized
concise form
32 Analytical Action Level (AAL) The term ldquoanalytical action levelrdquo is used to denote
the value of a quantity that will cause the decision-maker to choose one of the
alternative actions
33 Discrete Radioactive Particles (DRPs or ldquohot particlesrdquo) Particulate matter in a sample
of any matrix where a high concentration of radioactive material is contained in a tiny
104 Perform Continuing Instrument Quality Control Testing according to ASTM Standard
Practice D7282 Sections 20 21 and 24 ldquoContinuing Instrument Quality Control
Testingrdquo and ldquoQuality Control for Alpha Spectrometry Systemsrdquo (Reference 163)
11 Procedure
111 Rapid Curium Separation using TEVAreg and DGA Resins
NOTE This method addresses the analysis of soluble curium only Solid material if present must be
removed from the sample prior to aliquanting by filtering the unpreserved sample aliquant through a
045-μm filter The solid material may be screened for radioactivity or saved for potential future analysis
1111 Aliquanting and Preparation
11111 Aliquant 200 mL of sample into a 225-mL centrifuge tube
1 This helps minimize interference from alpha-emitting isotopes with potentially overlapping energies
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 10 Revision 0
11112 Aliquant a second 200 mL portion of one sample into a 225-mL
centrifuge tube as a sample duplicate
11113 Add 200 mL reagent water to an empty 225-mL centrifuge tube
as a reagent blank
11114 Add 200 mL reagent water to an empty 225-mL centrifuge tube
for the LCS
11115 Acidify each sample with concentrated HNO3 to a pH of less
than 20 by adding HNO3 This usually requires about 05 mL of
HNO3
11116 Add 10-40 dpm 244
Cm standard solution to the LCS centrifuge
tube following laboratory protocol
11117 Add 10-40 dpm 243
Am tracer to the blank LCS and sample and
sample duplicates following laboratory protocol
11118 Add 1 mL of 15 M Ca(NO3)2 3 mL of 32 M (NH4)2HPO4
solution and 2ndash3 drops of phenolphthalein indicator to each
centrifuge tube
11119 Slowly add concentrated NH4OH to each centrifuge tube with a
squeeze bottle Add enough NH4OH to reach a dark pink
phenolphthalein end point and form Ca3(PO4)2 precipitate Cap
and mix tubes and centrifuge at 2000 revolutions per minute
(rpm) or more for ~5 minutes
Note If a sample aliquant larger than 200 mL is needed the aliquant may be added to
a large beaker heated on a hot plate to near boiling with reagents added and allowed
to cool and settle After pouring off enough of the supernate the precipitate may be
transferred to a 225 mL tube rinsing the beaker well with water and centrifuged
111110 Decant supernatant solution and discard to waste
1112 Preparation of the Load Solution
11121 Dissolve the calcium phosphate precipitate with 15 mL of 3 M
HNO3 - 10 M Al(NO3)3 If the residue volume is large or if
residual solids remain an additional 5 mL may be needed to
obtain complete dissolution
11122 Add 05 mL of 15 M sulfamic acid to each sample Swirl to mix
NOTE If elevated levels of 237
Np are potentially present in the sample also add 05 mL
of 4 mgmL iron carrier to enhance neptunium (Np) reduction to Np4+
The addition of
ascorbic acid in the next step will convert Fe3+
to Fe2+
and ensure removal of Np on
TEVAreg Resin
11123 Add 125 mL of 15 M ascorbic acid to each sample Swirl to
mix Wait 3 minutes
NOTE Plutonium (Pu) if present will be adjusted to Pu4+
to ensure retention and
removal on TEVAreg Resin A small amount of brown fumes results from nitrite
reaction with sulfamic acid The solution should clear with swirling If the solution
does not clear (is still dark) an additional small volume of sodium nitrite may be
added to clear the solution
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 11 Revision 0
11124 Add 1 mL of 35 M NaNO2 to each sample Swirl to mix
NOTE The load solution nitrate concentration is increased after valence adjustment to
provide greater retention of Am and more effective elution of calcium ions on DGA
Resin
11125 Add 15 mL concentrated HNO3 to each sample and swirl to mix
NOTE The steps in this section were optimized for a commercially available filtration
system Other vacuum systems may be substituted here The cartridges may be set up
and conditioned with nitric acid so that they are ready for column loading just prior
to completion of the valence adjustment steps More than one vacuum box may be
used to increase throughput
1113 Set up TEVAreg and DGA cartridges on the vacuum box system
11131 Place the inner centrifuge tube rack (supplied with vacuum box)
into the vacuum box with the centrifuge tubes in the rack Place
the lid on the vacuum box system
11132 Place the yellow outer tips into all 24 openings of the lid of the
vacuum box Fit an inner white tip into each yellow tip
11133 For each sample assemble a TEVAreg and a DGA cartridge and
lock these onto the inner white tip (DGA cartridge below
TEVAreg
)
11134 Place reservoirs on the top end of the TEVAreg cartridge
11135 Seal unused openings on the vacuum box by inserting yellow
caps included with the vacuum box into unused white tips to
achieve a good seal during the separation Alternately plastic
tape can be used to seal the unused lid holes
11136 Turn the vacuum on and ensure proper fitting of the lid
11137 Add 5 mL of 3 M HNO3 to the column reservoir to precondition
the TEVAreg cartridges
11138 Adjust the vacuum to achieve a flow-rate of ~1 mLmin
IMPORTANT Unless the method specifies otherwise use a flow rate of ~ 1 mLmin
for load and strip solutions and ~ 2 -3 mLmin for rinse solutions
1114 TEVAreg
and DGA Resin Separation
11141 Transfer each solution from Step 11125 into the appropriate
reservoir Allow solution to pass through the stacked TEVAreg +
DGA cartridge at a flow rate of ~1 mLmin
11142 Add 5 mL of 6 M HNO3 to each tubebeaker as a rinse and
transfer each solution into the appropriate reservoir (the flow rate
can be adjusted to ~2 mLmin)
11143 Add a 5 mL rinse of 6 M HNO3 to each column (the flow rate
can be adjusted to ~2 mLmin)
11144 Turn off vacuum discard rinse solutions and remove reservoirs
and TEVAreg cartridges and discard Place new reservoirs on the
DGA cartridges
11145 Add a 20 mL rinse of 01 M HNO3 to each reservoir (flow rate
~1-2 mLmin)
NOTE The rinses with dilute nitric acid remove uranium while curium
and americium are retained Precipitation of uranium during
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 12 Revision 0
microprecipitation is inhibited by adding hydrogen peroxide to ensure
uranium is present as UO22+
11146 Add 15 mL of 3 M HNO3ndash025 M HF to each reservoir at ~1-2
mLmin to complex and remove Th from the DGA Resin
11147 Add 3 mL of 4 M HCl to each reservoir at ~1ndash2 mLmin to rinse
column of residual fluoride Once the HCl has passed through the
column quickly pulse the vacuum two or three times to
minimize the amount of residual HCl in the column prior to
proceeding
11148 Ensure that clean labeled plastic tubes are placed in the tube
rack under each cartridge For maximum removal of
interferences during elution also change connector tips prior to
CmAm elution
11149 Add 10 mL of 025 M HCl solution to elute curium and
americium from each cartridge reducing the flow rate to ~1
mLmin (or slightly slower)
111410 Set the curium fraction in the plastic tube aside for cerium
fluoride coprecipitation Step 112
111411 Discard the DGA cartridge
112 Preparation of the Sample Test Source
NOTE Instructions below describe preparation of a single sample test source (STS) Several
STSs can be prepared simultaneously if a multi-channel vacuum manifold system is available
1121 Pipet 100 microL of the cerium carrier solution into each tube
1122 Pipet 05 mL 30 wt H2O2 into each tube to prevent residual uranium from
precipitating
1123 Pipet 1 mL of concentrated HF into each tube
1124 Cap the tube and mix Allow samples sit for ~ 15 minutes before filtering
1125 Set up a filter apparatus to accommodate a 01-micron 25-mm membrane
filter on a microprecipitation filtering apparatus
Caution Following deposition of the microprecipitate there is no visible difference
between the two sides of the filter
1126 If a hydrophobic filter is used add a few drops of 95 ethanol to wet each
filter and apply vacuum Ensure that there are no leaks along the sides
before proceeding
1127 While vacuum is applied add 2-3 mL of filtered Type I water to each filter
and allow the liquid to drain
1128 Add the sample to the reservoir rinsing the sample tubes with ~3 mL of
water and transfer this rinse to filter apparatus Allow to drain
1129 Wash each filter with ~2-3 mL of water and allow to drain
11210 Wash each filter with ~1-2 mL of 95 ethanol to displace water
11211 Allow to drain completely before turning the vacuum off
11212 Mount the filter on a labeled adhesive mounting disk (or equivalent)
ensuring that the filter is not wrinkled and is centered on the mounting disk
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 13 Revision 0
11213 Place the filter under a heat lamp for approximately 5 minutes or longer
until it is completely dry
11214 Count filters for an appropriate period of time by alpha spectrometry
11215 Discard the filtrate to waste for future disposal If the filtrate is to be
retained it should be stored in a plastic container since glass will be
attacked by HF
NOTE Other methods for STS preparation such as electrodeposition or
microprecipitation with neodymium fluoride may be used in lieu of the cerium
fluoride microprecipitation but any such substitution must be validated as described
in Step 15
12 Data Analysis and Calculations
121 Equations for activity concentration combined standard uncertainty and
radiochemical yield (if required)
1211 The activity concentration of the analyte and its combined standard
uncertainty are calculated using the following equations
aata
ttata
IDRV
IDRAAC
2
t
t
2
2
a
a
2
2
t
t
22
a2
a
2
a
2
t
2
a
2
t
2
t
2
ta
2
ac
)()()()()(
R
Ru
V
Vu
A
AuAC
IDRV
IDARuACu
ttt
tD
e
aat
aD
e
Where
ACa = activity concentration of the analyte at time of collection (or other
specified reference time) in picocuries per liter (pCiL)
At = activity of the tracer added to the sample aliquant on the tracer
solution reference datetime (pCi)
Ra = net count rate of the analyte in the defined region of interest (ROI)
in counts per second (see 1212)
Rt = net count rate of the tracer in the defined ROI in counts per second
(see 1212)
Va = volume of the sample aliquant (L)
Dt = correction factor for decay of the tracer from its reference date and
time to the midpoint of the counting period
Da = correction factor for decay of the analyte from the time of sample
collection (or other reference time) to the midpoint of the counting
period
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 14 Revision 0
It = probability of α emission in the defined ROI per decay of the tracer
(Table 171)
Ia = probability of α emission in the defined ROI per decay of the analyte
(Table 171)
uc(ACa) = combined standard uncertainty of the activity concentration of the
analyte (pCiL)
u(At) = standard uncertainty of the activity of the tracer added to the sample
(pCi)
u(Ra) = standard uncertainty of the net count rate of the analyte (sminus1
) (see
1212)
u(Rt) = standard uncertainty of the net count rate of the tracer (sminus1
) (see
1212)
u(Va) = standard uncertainty of the size of the sample aliquant volume (L)
λt = decay constant for the tracer radionuclide (sminus1
see Table 171)
λa = decay constant for the analyte radionuclide (sminus1
see Table 171)
tt = time elapsed between the activity reference date for the tracer and
the midpoint of the sample count (s)
ta = time elapsed between the activity reference date for the sample (eg
collection date) and the midpoint of the sample count (s)
NOTE The uncertainties of the decay-correction factors and of the probability of decay
factors are assumed to be negligible
NOTE The equation for the combined standard uncertainty (uc(ACa)) calculation is arranged to
eliminate the possibility of dividing by zero if Ra = 0
NOTE The standard uncertainty of the activity of the tracer added to the sample must reflect the
uncertainty associated with the activity of the standard reference material and any other
significant sources of uncertainty such as those introduced during the preparation of the tracer
solution (eg weighing or dilution factors) and during the process of adding the tracer to the
sample
1212 The net count rate of an analyte or tracer and its standard uncertainty are
calculated using the following equations
b
bx
s
xx
t
C
t
CR
and
2
b
bx
2
s
xx
11)(
t
C
t
CRu
where
Rx = net count rate of analyte or tracer in counts per second
Cx = sample counts in the analyte or the tracer ROI
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 15 Revision 0
ts = sample count time (s)
Cbx = background counts in the same ROI as for x
tb = background count time (s)
u(Rx) = standard uncertainty of the net count rate of tracer or analyte in
counts per second2
If the radiochemical yield of the tracer is requested the yield and its combined
standard uncertainty can be calculated using the following equations
ttt
t
0370 IDA
RRY
and
2
2
2
t
t
2
2
t
t
2)()()(
)(
u
A
Au
R
RuRYRYuc
where
RY = radiochemical yield of the tracer expressed as a fraction
Rt = net count rate of the tracer in counts per second
At = activity of the tracer added to the sample (pCi)
Dt = correction factor for decay of the tracer from its reference date and
time to the midpoint of the counting period
It = probability of α emission in the defined ROI per decay of the tracer
(Table 171)
ε = detector efficiency expressed as a fraction
uc(RY) = combined standard uncertainty of the radiochemical yield
u(Rt) = standard uncertainty of the net count rate of the tracer in counts per
second
u(At) = standard uncertainty of the activity of the tracer added to the sample
(pCi)
u(ε) = standard uncertainty of the detector efficiency
1213 If the critical level concentration (Lc) or the minimum detectable
concentration (MDC) are requested (at an error rate of 5) they can be
calculated using the following equations 3
2 For methods with very low counts MARLAP Section 19522 recommends adding one count each to the gross
counts and the background counts when estimating the uncertainty of the respective net counts This minimizes
negative bias in the estimate of uncertainty and protects against calculating zero uncertainty when a total of zero
counts are observed for the sample and background 3 The formulations for the critical level and minimum detectable concentration are based on the Stapleton
Approximation as recommended in MARLAP Section 20A22 Equations 2054 and 20A32 and Equation 2074
respectively (EPA 2004) The formulations presented here assume an error rate of α = 005 β = 005 (with z1minusα =
z1minusβ = 1645) and d = 04 For methods with very low numbers of counts these expressions provide better estimates
than do the traditional formulas for the critical level and MDC
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 16 Revision 0
aatas
ttt
b
s
b
sbba
b
s
b
s
cIDRVt
IDAt
t
t
ttR
t
t
t
t
L
140645116770140
aatas
ttt
b
ssba
b
s 13291271
MDCIDRVt
IDAt
ttR
t
t
where
Rba = background count rate for the analyte in the defined ROI in counts
per second
122 Results Reporting
1221 The following data should be reported for each result volume of sample
used yield of tracer and its uncertainty and FWHM of each peak used in
the analysis
1222 The following conventions should be used for each result
12221 Result in scientific notation plusmn combined standard uncertainty
13 Method Performance
131 Method validation results performed prior to analyzing samples are to be documented
and reported as required
132 Expected processing time per batch of 10-20 samples plus QC
1321 For an analysis of a 02 L sample aliquant precipitation and preparation of
load solution takes ~1 h
1322 Purification and separation using cartridges and vacuum box system should
take ~2 h
1323 The sample test source preparation step takes ~075 h
1324 A four-hour counting time should be sufficient to meet the MQOs listed in
Step 14 assuming detector efficiency of 015ndash03 and radiochemical yield
of at least 05 A different counting time may be necessary to meet these
MQOs if any of the relevant parameters are significantly different
1325 Data should be ready for reduction ~8-9 h after beginning of analysis
14 Pollution Prevention The method utilizes small volume (2 mL) extraction chromatographic
resin columns This approach leads to a significant reduction in the volumes of load rinse
and strip solutions as compared to classical methods using ion exchange resins to separate
and purify the curium fraction
15 Waste Management
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 17 Revision 0
151 Types of waste generated per sample analyzed
1511 Approximately 210 mL basic waste from the initial sample
preconcentration
1512 Approximately 65 mL of acidic waste from loading and rinsing the two
extraction columns will be generated
1513 Approximately 25 mL of acidic waste from the microprecipitation method
for source preparation will be generated The waste contains 1 mL of HF
and ~ 5 mL of ethanol
1514 TEVAreg
cartridge ndash ready for appropriate disposal
1515 DGA cartridge ndash ready for appropriate disposal
1516 These waste streams may contain low levels of 243
Am (added as tracer) 244
Cm (added to LCS) and other radionuclides as present in samples
152 Evaluate all waste streams according to disposal requirements by applicable
regulations
16 References
Cited References
161 EPA 2009 Method Validation Guide for Radiological Laboratories Participating in
Incident Response Activities Revision 0 Office of Air and Radiation Washington
(MARLAP) 2004 EPA 402-B-1304 04-001A July Volume I Chapters 6 7 20
Glossary Volume II and Volume III Appendix G Available here
163 ASTM D7282 ldquoStandard Practice for Set-up Calibration and Quality Control of
Instruments Used for Radioactivity Measurementsrdquo ASTM Book of Standards 1102
current version ASTM International West Conshohocken PA
164 ASTM D1193 ldquoStandard Specification for Reagent Waterrdquo ASTM Book of Standards
1102 current version ASTM International West Conshohocken PA
Other References
165 EPA 2012 Rapid Radiochemical Method for Americium-241 in Building Materials
for Environmental Remediation Following Radiological Incidents Office of Air and
Radiation Washington DC Available here
166 Maxwell S Culligan B and Noyes G 2010 Rapid Separation Method for Actinides
in Emergency Soil Samples Radiochimica Acta 98(12) 793-800
167 Maxwell S Culligan B Kelsey-Wall A and Shaw P 2011 ldquoRapid Radiochemical
Method for Determination of Actinides in Emergency Concrete and Brick Samplesrdquo
Analytica Chimica Acta 701(1) 112-8
168 VBS01 Rev14 ldquoSetup and Operation Instructions for Eichromrsquos Vacuum Box
System (VBS)rdquo Eichrom Technologies LLC Lisle Illinois (January 2014)
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 18 Revision 0
17 Tables Diagrams Flow Charts and Validation Data
171 Tables
Table 171 Alpha Particle Energies and Abundances of Importance[1]
Nuclide Half-Life
(Years)
λ
(sminus1
) Abundance
α Emission Energy
in kilo electron volts
244Cm
1811 1213times10
minus09
07690 5805
02310 5763
243Cm
291 755times10
minus10
00150 6066
0047 6058
0010968 6010
00568 5992
00069797 5876
0730 5785
0115 5742
0015954 5686
00019942 5682
00013959 5639 244243
Cm (combined) 1811 1213times10
minus09 1000 5805
242Cm
04462 4923times10minus08
02592 6113
07408 6069
245Cm
850times10
3 258times10
minus12
00058 5529
00083 5489
00045 5370
09320 5361
05000 5304
00032 5234
246Cm
476times10
3 461times10
minus12
0822 5387
0178 5344
247Cm
1560times10
7 1408times10
minus15
0138 5267
0057 5212
00120 5147
00200 4985
00160 4943
0710 4870
0047 4820
243Am
7370times10
3 2980times10
minus12
00016 5349
00016 5321
0871 5275
0112 5233
00136 5181 243
Am (combined) 7370times10
3 2980times10
minus12 09998 5275
241Am
4326 5078times10
minus11
00037 5545
000225 5512
0848 5486
0131 5443
001660 5388
[1] Particle energies with abundances less than 01 have been omitted unless they are contiguous with the
radionuclide region of interest
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 19 Revision 0
Data were queried from the NUDAT 2 Decay Radiation database at the Brookhaven National Laboratory National
Nuclear Data Center (httpwwwnndcbnlgovnudat2indx_decjsp) on 9192014
Table 172 Alpha Emissions Sorted by Decreasing Energy
Nuclide Half-Life
(years) λ
(sminus1
) α Emission
Energy (keV)[1]
Abundance 242
Cm 04462 4923times10-08
6113 07408 242
Cm 04462 4923times10-08
6069 02592 243
Cm 291 755times10-10
6066 00150 243
Cm 291 755times10-10
6058 0047 243
Cm 291 755times10-10
6010 0010968 243
Cm 291 755times10-10
5992 00568 243
Cm 291 755times10-10
5876 00069797 244
Cm 1811 1213times10-09
5805 07690 243
Cm 291 755times10-10
5785 0730 244
Cm 1811 1213times10-09
5763 02310 243
Cm 291 755times10-10
5742 0115 243
Cm 291 755times10-10
5686 0015954 243
Cm 291 755times10-10
5682 00019942 243
Cm 291 755times10-10
5639 00013959 241
Am 4326times102 5078times10
-11 5545 00037
245Cm 850times10
3 258times10
-12 5529 00058
241Am 4326times10
2 5078times10
-11 5512 000225
245Cm 850times10
3 258times10
-12 5489 00083
241Am 4326times10
2 5078times10
-11 5486 0848
241Am 4326times10
2 5078times10
-11 5443 0131
241Am 4326times10
2 5078times10
-11 5388 001660
246Cm 476times10
3 461times10
-12 5387 0822
245Cm 850times10
3 258times10
-12 5370 00045
245Cm 850times10
3 258times10
-12 5361 09320
243Am 7370times10
3 2980times10
-12 5349 00016
246Cm 476times10
3 461times10
-12 5344 0178
243Am 7370times10
3 2980times10
-12 5321 00016
245Cm 850times10
3 258times10
-12 5304 05000
243Am 7370times10
3 2980times10
-12 5275 0871
247Cm 1560times10
7 1408times10
-15 5267 0138
245Cm 850times10
3 258times10
-12 5234 00032
243Am 7370times10
3 2980times10
-12 5233 0112
247Cm 1560times10
7 1408times10
-15 5212 0057
247Cm 1560times10
7 1408times10
-15 5147 00120
247Cm 1560times10
7 1408times10
-15 4985 00200
247Cm 1560times10
7 1408times10
-15 4943 00160
247Cm
1560times107 1408times10
-15 4870 0710
247Cm
1560times107 1408times10
-15 4820 0047
[1]Particle energies with abundances less than 01 have been omitted unless they would be contiguous with the
radionuclide region of interest
Data were queried from the NUDAT 2 Decay Radiation database at Brookhaven National Laboratory National
Nuclear Data Center (httpwwwnndcbnlgovnudat2indx_decjsp) on 9192014
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 20 Revision 0
Ingrowth Curves and Ingrowth Factors
This section intentionally left blank
172 Spectrum from a Processed Sample
Curium-244 Spectrum
173 Decay Scheme
244Cm
240Pu
tfrac12=1811 y
tfrac12= 6561times10
3y
α
α
243Am
239Np
tfrac12=7330y
239Pu
tfrac12=619m
β
243Cm
239Pu
tfrac12=291 y
tfrac12= 2411times10
4y
α
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 21 Revision 0
174 Flow Chart
Separation Scheme and Timeline for theDetermination of 244Cm in Water Samples
Aliquant preparation batch
bull Aliquant 200 mL of each sample and QC sample into
centrifuge tubes (11111 - 11114)
bull Acidify with HNO3 to pH lt 2 (11115)
bull Add 244Cm to LCS and 243Am tracer to all samples
(11116- 11117)
Elapsed Time
1 hour
Vacuum box setup
bull Assemble TEVAreg +
DGA cartridges on
vacuum box (11131 -
11135)
bull Condition cartridges with
3M HNO3 and adjust
f low to ~1 mLmin
(11136 - 11138)
Load sample onto TEVAreg amp DGA cartridges
bull Load sample 1 mLmin (11141)
bull Add 5 mL 6M HNO3 tube rinse to column ~2 mLmin (11142)
bull Rinse column with 5 mL 6 MHNO3 ~2 mLmin (11143)
Prepare load solution adjust Pu to Pu4+
bull Dissolve Ca3(PO4)2 with 15 mL HNO3Al(NO3)3 (11121)
bull Add 05 mL 15M sulfamic acid and swirl to mix (11122)
bull Add 125 mL 15M ascorbic acid and swirl to mix and
wait 3 minutes (11123)
bull Add 1 mL 35M sodium nitrite and swirl to mix (11124)
bull Add 15 mL concentrated nitric acid and swirl to mix
(11125)
bull Discard TEVAreg cartridge and load
and rinse solutions (11144)
bull Place f resh reservoirs above each
cartridge (11144)
Continue with Step 11145
frac34 hour
Calcium phosphate preconcentration
bull Add 1 mL 15M Ca(NO3)2 3 mL 32M (NH4)2HPO4
and 2-3 drops phenolphthalein indicator (11118)
bull Add 15M NH4OH to pink phenolphthalein endpoint to
precipitate Ca3(PO4)2 and centrifuge (11119)
bull Decant supernate to waste (111110)
2 hours
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 22 Revision 0
Microprecipitation and sample test source preparation
bull Add 100 microL (50 microg) Ce carrier to each sample (1121)
bull Add 05 mL 30 wt H2O2 (1122)
bull Add 1 mL concentrated HF into each sample (1123)
bull Cap tube mix and wait 15 min (1124)
bull Set up f iltering apparatus (1125 - 1127)
bull Filter sample onto 25-mm 01-microm membrane f ilter (1128)
bull Rinse with ~2-3 mL water and allow to drain (1129)
bull Rinse with ~1-2 mL alcohol to displace water (11210-11211)
bull Mount f ilter for counting (11212)
bull Place f ilter under heat lamp under gentle heat for ~5 min (11213)
Elapsed Time
Cm separation on DGA Resin
bull Rinse column with 20 mL 01M HNO3 ~1-2 mLmin (11145)
bull Rinse column with 15 mL 3M HNO3-025M HF ~1-2 mLmin (11146)
bull Rinse column with 3 mL 4M HCl ~1-2 mLmin remove excess HCl f rom
column (11147)
bull Place f resh connector tips under each column and tubes under each column to
catch Cm (11148)
bull Elute Cm with 10 mL 025M HCl ~1 mLmin (11149)
bull Remove tubes for microprecipitation and continue with Step 112 (111410)
Discard DGA cartridge (111411)
Discard filtrates and rinses (11215)
Continue from Step 11144 2 hours
3 hours
3 frac34 hours
8 hours
Separation Scheme and Timeline for theDetermination of 244Cm in Water Samples (cont)
Count sample test sources (STS)
by alpha spectrometry for 244Cm and 243Am for
four hours or as needed to meet MQOs
(11214)
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 23 Revision 0
Appendix A Composition of Test Samples Used for Validation
Metals by ICP-MS Concentration (μgL) amp Be 0015 (J)
Na 3400
Mg 1500
Al 15 (J)
K 1500
Ca 17000
V 030 (J)
Cr 0075 (J)
Mn 63
Fe 26 (J)
Co 0047 (J)
Ni 069 (J)
Cu 59
Zn 80
As 027 (J)
Se 011 (J)
Mo lt041 (U)
Ag lt00082 (U)
Cd 0010 (J)
Sb 0060 (J)
Ba 20
Tl 0054 (J)
Pb 023 (J)
U 0010 (J)
Radionuclide Activity Concentration (pCiL) 244
Cm 0012 plusmn 0050
252250Cf 0001 plusmn 0044
241Am 020 plusmn 029
232Th
230Th
228Th
0003 plusmn 0034 amp
0052 plusmn 0081 amp
031 plusmn 012 amp
238U
235U
234U
018 plusmn 012 amp
0219 plusmn 0095 amp
0232 plusmn 0096 amp
226Ra 0049 plusmn 0024
amp
Qualifiers (U) ndash Result is less than the Instrument Detection Limit (IDL) per
SW846 Method 6020A
(J) ndash Result falls between the IDL and the reporting limit amp Mean plusmn 2 standard deviations of triplicate analyses of each of two Montgomery
Alabama tap water Mean plusmn 2 standard deviations of replicate analysis of seven samples of
Montgomery Alabama tap water
Rapid Radiochemical Method for Curium-244 in Air Particulate Filters Swipes and Soils
Revision History
Revision 0 Original release 05-01-2016
This report was prepared for the National Analytical Radiation Environmental Laboratory of the Office of Radiation and Indoor Air and the National Homeland Security Research Center of the US Environmental Protection Agencyrsquos (EPA) Office of Research and Development It was prepared by Environmental Management Support Inc of Silver Spring Maryland under contract EP-W-13-016 task order 014 managed by Dan Askren This document has been reviewed in accordance with EPA policy and approved for publication Note that approval does not signify that the contents necessarily reflect the views of the Agency Mention of trade names products or services does not convey EPA approval endorsement or recommendation
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 3 Revision 0
RAPID RADIOCHEMICAL METHOD FOR CM-244 IN WATER SAMPLES FOR
ENVIRONMENTAL REMEDIATION FOLLOWING RADIOLOGICAL INCIDENTS
1 Scope and Application
11 This method provides for the rapid determination of 244
Cm in water samples
12 The method uses radiochemical separation techniques to rapidly isolate curium from a
water matrix using 243
Am tracer as a yield monitor
13 A sample test source is prepared by microprecipitation The test source is counted by
alpha spectrometry for 244
Cm
131 Cm-243 emits alpha particles that are isoenergetic with 244
Cm Alpha
spectrometry measurements that show activity in the region of interest for 244
Cm should be reported as 244243
Cm
14 This method is capable of achieving a required method uncertainty for 244
Cm of 20
pCiL at an analytical action level of 15 pCiL To attain the stated measurement
quality objectives (MQOs) a sample volume of approximately 02 L and count time
of at least 4 hours are recommended Sample count times may vary based on
differences in instrument parameters such as detection efficiency and background
15 The 244
Cm method was single-laboratory evaluated following the guidance presented
for Level E Method Validation Adapted or Newly Developed Methods Including
rapid methodsrdquo in Method Validation Guide for Qualifying Methods Used by
Radiological Laboratories Participating in Incident Response Activities (Reference
161) and Chapter 6 of the Multi-Agency Radiological Laboratory Analytical
Protocols Manual (MARLAP Reference 162)
151 Since californium and americium track closely with curium through the
chemical separation it may be possible to determine isotopes of
californium as well as isotopes of americium (eg 241
Am) that may be
present in the sample test source The specific method performance (yield
required method uncertainty [uMR] minimum detectable activity and critical
level) for other isotopes of californium americium or curium (eg 249
Cf 241
Am or 244243
Cm must be validated by the laboratory prior to performing
determinations for these radionuclides)
152 The sample turnaround time and throughput may vary based on additional
project MQOs the time for analysis of the sample test source and initial
sample weight volume
153 The method must be validated prior to use following the protocols provided
in Method Validation Guide for Qualifying Methods Used by Radiological
Laboratories Participating in Incident Response Activities (Reference 161)
2 Summary of Method
21 This method is based on the use of extraction chromatography resins (TEVAreg + DGA
Resins) to isolate and purify curium by removing interfering radionuclides and other
matrix components and prepare the curium fraction for counting by alpha
spectrometry The method utilizes vacuum-assisted flow to improve the speed of the
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 4 Revision 0
separations An 243
Am tracer is equilibrated with the water sample and used as a yield
monitor Following chemical separation of Cm and Am the sample test source (STS)
is prepared by microprecipitation with cerium fluoride (CeF3) The alpha emissions
from the source are measured using an alpha spectrometer and used to calculate the
activity of 244
Cm in the sample
3 Definitions Abbreviations and Acronyms
31 Analytical Protocol Specifications (APS) The output of a directed planning process
that contains the projectrsquos analytical data needs and requirements in an organized
concise form
32 Analytical Action Level (AAL) The term ldquoanalytical action levelrdquo is used to denote
the value of a quantity that will cause the decision-maker to choose one of the
alternative actions
33 Discrete Radioactive Particles (DRPs or ldquohot particlesrdquo) Particulate matter in a sample
of any matrix where a high concentration of radioactive material is contained in a tiny
104 Perform Continuing Instrument Quality Control Testing according to ASTM Standard
Practice D7282 Sections 20 21 and 24 ldquoContinuing Instrument Quality Control
Testingrdquo and ldquoQuality Control for Alpha Spectrometry Systemsrdquo (Reference 163)
11 Procedure
111 Rapid Curium Separation using TEVAreg and DGA Resins
NOTE This method addresses the analysis of soluble curium only Solid material if present must be
removed from the sample prior to aliquanting by filtering the unpreserved sample aliquant through a
045-μm filter The solid material may be screened for radioactivity or saved for potential future analysis
1111 Aliquanting and Preparation
11111 Aliquant 200 mL of sample into a 225-mL centrifuge tube
1 This helps minimize interference from alpha-emitting isotopes with potentially overlapping energies
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 10 Revision 0
11112 Aliquant a second 200 mL portion of one sample into a 225-mL
centrifuge tube as a sample duplicate
11113 Add 200 mL reagent water to an empty 225-mL centrifuge tube
as a reagent blank
11114 Add 200 mL reagent water to an empty 225-mL centrifuge tube
for the LCS
11115 Acidify each sample with concentrated HNO3 to a pH of less
than 20 by adding HNO3 This usually requires about 05 mL of
HNO3
11116 Add 10-40 dpm 244
Cm standard solution to the LCS centrifuge
tube following laboratory protocol
11117 Add 10-40 dpm 243
Am tracer to the blank LCS and sample and
sample duplicates following laboratory protocol
11118 Add 1 mL of 15 M Ca(NO3)2 3 mL of 32 M (NH4)2HPO4
solution and 2ndash3 drops of phenolphthalein indicator to each
centrifuge tube
11119 Slowly add concentrated NH4OH to each centrifuge tube with a
squeeze bottle Add enough NH4OH to reach a dark pink
phenolphthalein end point and form Ca3(PO4)2 precipitate Cap
and mix tubes and centrifuge at 2000 revolutions per minute
(rpm) or more for ~5 minutes
Note If a sample aliquant larger than 200 mL is needed the aliquant may be added to
a large beaker heated on a hot plate to near boiling with reagents added and allowed
to cool and settle After pouring off enough of the supernate the precipitate may be
transferred to a 225 mL tube rinsing the beaker well with water and centrifuged
111110 Decant supernatant solution and discard to waste
1112 Preparation of the Load Solution
11121 Dissolve the calcium phosphate precipitate with 15 mL of 3 M
HNO3 - 10 M Al(NO3)3 If the residue volume is large or if
residual solids remain an additional 5 mL may be needed to
obtain complete dissolution
11122 Add 05 mL of 15 M sulfamic acid to each sample Swirl to mix
NOTE If elevated levels of 237
Np are potentially present in the sample also add 05 mL
of 4 mgmL iron carrier to enhance neptunium (Np) reduction to Np4+
The addition of
ascorbic acid in the next step will convert Fe3+
to Fe2+
and ensure removal of Np on
TEVAreg Resin
11123 Add 125 mL of 15 M ascorbic acid to each sample Swirl to
mix Wait 3 minutes
NOTE Plutonium (Pu) if present will be adjusted to Pu4+
to ensure retention and
removal on TEVAreg Resin A small amount of brown fumes results from nitrite
reaction with sulfamic acid The solution should clear with swirling If the solution
does not clear (is still dark) an additional small volume of sodium nitrite may be
added to clear the solution
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 11 Revision 0
11124 Add 1 mL of 35 M NaNO2 to each sample Swirl to mix
NOTE The load solution nitrate concentration is increased after valence adjustment to
provide greater retention of Am and more effective elution of calcium ions on DGA
Resin
11125 Add 15 mL concentrated HNO3 to each sample and swirl to mix
NOTE The steps in this section were optimized for a commercially available filtration
system Other vacuum systems may be substituted here The cartridges may be set up
and conditioned with nitric acid so that they are ready for column loading just prior
to completion of the valence adjustment steps More than one vacuum box may be
used to increase throughput
1113 Set up TEVAreg and DGA cartridges on the vacuum box system
11131 Place the inner centrifuge tube rack (supplied with vacuum box)
into the vacuum box with the centrifuge tubes in the rack Place
the lid on the vacuum box system
11132 Place the yellow outer tips into all 24 openings of the lid of the
vacuum box Fit an inner white tip into each yellow tip
11133 For each sample assemble a TEVAreg and a DGA cartridge and
lock these onto the inner white tip (DGA cartridge below
TEVAreg
)
11134 Place reservoirs on the top end of the TEVAreg cartridge
11135 Seal unused openings on the vacuum box by inserting yellow
caps included with the vacuum box into unused white tips to
achieve a good seal during the separation Alternately plastic
tape can be used to seal the unused lid holes
11136 Turn the vacuum on and ensure proper fitting of the lid
11137 Add 5 mL of 3 M HNO3 to the column reservoir to precondition
the TEVAreg cartridges
11138 Adjust the vacuum to achieve a flow-rate of ~1 mLmin
IMPORTANT Unless the method specifies otherwise use a flow rate of ~ 1 mLmin
for load and strip solutions and ~ 2 -3 mLmin for rinse solutions
1114 TEVAreg
and DGA Resin Separation
11141 Transfer each solution from Step 11125 into the appropriate
reservoir Allow solution to pass through the stacked TEVAreg +
DGA cartridge at a flow rate of ~1 mLmin
11142 Add 5 mL of 6 M HNO3 to each tubebeaker as a rinse and
transfer each solution into the appropriate reservoir (the flow rate
can be adjusted to ~2 mLmin)
11143 Add a 5 mL rinse of 6 M HNO3 to each column (the flow rate
can be adjusted to ~2 mLmin)
11144 Turn off vacuum discard rinse solutions and remove reservoirs
and TEVAreg cartridges and discard Place new reservoirs on the
DGA cartridges
11145 Add a 20 mL rinse of 01 M HNO3 to each reservoir (flow rate
~1-2 mLmin)
NOTE The rinses with dilute nitric acid remove uranium while curium
and americium are retained Precipitation of uranium during
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 12 Revision 0
microprecipitation is inhibited by adding hydrogen peroxide to ensure
uranium is present as UO22+
11146 Add 15 mL of 3 M HNO3ndash025 M HF to each reservoir at ~1-2
mLmin to complex and remove Th from the DGA Resin
11147 Add 3 mL of 4 M HCl to each reservoir at ~1ndash2 mLmin to rinse
column of residual fluoride Once the HCl has passed through the
column quickly pulse the vacuum two or three times to
minimize the amount of residual HCl in the column prior to
proceeding
11148 Ensure that clean labeled plastic tubes are placed in the tube
rack under each cartridge For maximum removal of
interferences during elution also change connector tips prior to
CmAm elution
11149 Add 10 mL of 025 M HCl solution to elute curium and
americium from each cartridge reducing the flow rate to ~1
mLmin (or slightly slower)
111410 Set the curium fraction in the plastic tube aside for cerium
fluoride coprecipitation Step 112
111411 Discard the DGA cartridge
112 Preparation of the Sample Test Source
NOTE Instructions below describe preparation of a single sample test source (STS) Several
STSs can be prepared simultaneously if a multi-channel vacuum manifold system is available
1121 Pipet 100 microL of the cerium carrier solution into each tube
1122 Pipet 05 mL 30 wt H2O2 into each tube to prevent residual uranium from
precipitating
1123 Pipet 1 mL of concentrated HF into each tube
1124 Cap the tube and mix Allow samples sit for ~ 15 minutes before filtering
1125 Set up a filter apparatus to accommodate a 01-micron 25-mm membrane
filter on a microprecipitation filtering apparatus
Caution Following deposition of the microprecipitate there is no visible difference
between the two sides of the filter
1126 If a hydrophobic filter is used add a few drops of 95 ethanol to wet each
filter and apply vacuum Ensure that there are no leaks along the sides
before proceeding
1127 While vacuum is applied add 2-3 mL of filtered Type I water to each filter
and allow the liquid to drain
1128 Add the sample to the reservoir rinsing the sample tubes with ~3 mL of
water and transfer this rinse to filter apparatus Allow to drain
1129 Wash each filter with ~2-3 mL of water and allow to drain
11210 Wash each filter with ~1-2 mL of 95 ethanol to displace water
11211 Allow to drain completely before turning the vacuum off
11212 Mount the filter on a labeled adhesive mounting disk (or equivalent)
ensuring that the filter is not wrinkled and is centered on the mounting disk
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 13 Revision 0
11213 Place the filter under a heat lamp for approximately 5 minutes or longer
until it is completely dry
11214 Count filters for an appropriate period of time by alpha spectrometry
11215 Discard the filtrate to waste for future disposal If the filtrate is to be
retained it should be stored in a plastic container since glass will be
attacked by HF
NOTE Other methods for STS preparation such as electrodeposition or
microprecipitation with neodymium fluoride may be used in lieu of the cerium
fluoride microprecipitation but any such substitution must be validated as described
in Step 15
12 Data Analysis and Calculations
121 Equations for activity concentration combined standard uncertainty and
radiochemical yield (if required)
1211 The activity concentration of the analyte and its combined standard
uncertainty are calculated using the following equations
aata
ttata
IDRV
IDRAAC
2
t
t
2
2
a
a
2
2
t
t
22
a2
a
2
a
2
t
2
a
2
t
2
t
2
ta
2
ac
)()()()()(
R
Ru
V
Vu
A
AuAC
IDRV
IDARuACu
ttt
tD
e
aat
aD
e
Where
ACa = activity concentration of the analyte at time of collection (or other
specified reference time) in picocuries per liter (pCiL)
At = activity of the tracer added to the sample aliquant on the tracer
solution reference datetime (pCi)
Ra = net count rate of the analyte in the defined region of interest (ROI)
in counts per second (see 1212)
Rt = net count rate of the tracer in the defined ROI in counts per second
(see 1212)
Va = volume of the sample aliquant (L)
Dt = correction factor for decay of the tracer from its reference date and
time to the midpoint of the counting period
Da = correction factor for decay of the analyte from the time of sample
collection (or other reference time) to the midpoint of the counting
period
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 14 Revision 0
It = probability of α emission in the defined ROI per decay of the tracer
(Table 171)
Ia = probability of α emission in the defined ROI per decay of the analyte
(Table 171)
uc(ACa) = combined standard uncertainty of the activity concentration of the
analyte (pCiL)
u(At) = standard uncertainty of the activity of the tracer added to the sample
(pCi)
u(Ra) = standard uncertainty of the net count rate of the analyte (sminus1
) (see
1212)
u(Rt) = standard uncertainty of the net count rate of the tracer (sminus1
) (see
1212)
u(Va) = standard uncertainty of the size of the sample aliquant volume (L)
λt = decay constant for the tracer radionuclide (sminus1
see Table 171)
λa = decay constant for the analyte radionuclide (sminus1
see Table 171)
tt = time elapsed between the activity reference date for the tracer and
the midpoint of the sample count (s)
ta = time elapsed between the activity reference date for the sample (eg
collection date) and the midpoint of the sample count (s)
NOTE The uncertainties of the decay-correction factors and of the probability of decay
factors are assumed to be negligible
NOTE The equation for the combined standard uncertainty (uc(ACa)) calculation is arranged to
eliminate the possibility of dividing by zero if Ra = 0
NOTE The standard uncertainty of the activity of the tracer added to the sample must reflect the
uncertainty associated with the activity of the standard reference material and any other
significant sources of uncertainty such as those introduced during the preparation of the tracer
solution (eg weighing or dilution factors) and during the process of adding the tracer to the
sample
1212 The net count rate of an analyte or tracer and its standard uncertainty are
calculated using the following equations
b
bx
s
xx
t
C
t
CR
and
2
b
bx
2
s
xx
11)(
t
C
t
CRu
where
Rx = net count rate of analyte or tracer in counts per second
Cx = sample counts in the analyte or the tracer ROI
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 15 Revision 0
ts = sample count time (s)
Cbx = background counts in the same ROI as for x
tb = background count time (s)
u(Rx) = standard uncertainty of the net count rate of tracer or analyte in
counts per second2
If the radiochemical yield of the tracer is requested the yield and its combined
standard uncertainty can be calculated using the following equations
ttt
t
0370 IDA
RRY
and
2
2
2
t
t
2
2
t
t
2)()()(
)(
u
A
Au
R
RuRYRYuc
where
RY = radiochemical yield of the tracer expressed as a fraction
Rt = net count rate of the tracer in counts per second
At = activity of the tracer added to the sample (pCi)
Dt = correction factor for decay of the tracer from its reference date and
time to the midpoint of the counting period
It = probability of α emission in the defined ROI per decay of the tracer
(Table 171)
ε = detector efficiency expressed as a fraction
uc(RY) = combined standard uncertainty of the radiochemical yield
u(Rt) = standard uncertainty of the net count rate of the tracer in counts per
second
u(At) = standard uncertainty of the activity of the tracer added to the sample
(pCi)
u(ε) = standard uncertainty of the detector efficiency
1213 If the critical level concentration (Lc) or the minimum detectable
concentration (MDC) are requested (at an error rate of 5) they can be
calculated using the following equations 3
2 For methods with very low counts MARLAP Section 19522 recommends adding one count each to the gross
counts and the background counts when estimating the uncertainty of the respective net counts This minimizes
negative bias in the estimate of uncertainty and protects against calculating zero uncertainty when a total of zero
counts are observed for the sample and background 3 The formulations for the critical level and minimum detectable concentration are based on the Stapleton
Approximation as recommended in MARLAP Section 20A22 Equations 2054 and 20A32 and Equation 2074
respectively (EPA 2004) The formulations presented here assume an error rate of α = 005 β = 005 (with z1minusα =
z1minusβ = 1645) and d = 04 For methods with very low numbers of counts these expressions provide better estimates
than do the traditional formulas for the critical level and MDC
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 16 Revision 0
aatas
ttt
b
s
b
sbba
b
s
b
s
cIDRVt
IDAt
t
t
ttR
t
t
t
t
L
140645116770140
aatas
ttt
b
ssba
b
s 13291271
MDCIDRVt
IDAt
ttR
t
t
where
Rba = background count rate for the analyte in the defined ROI in counts
per second
122 Results Reporting
1221 The following data should be reported for each result volume of sample
used yield of tracer and its uncertainty and FWHM of each peak used in
the analysis
1222 The following conventions should be used for each result
12221 Result in scientific notation plusmn combined standard uncertainty
13 Method Performance
131 Method validation results performed prior to analyzing samples are to be documented
and reported as required
132 Expected processing time per batch of 10-20 samples plus QC
1321 For an analysis of a 02 L sample aliquant precipitation and preparation of
load solution takes ~1 h
1322 Purification and separation using cartridges and vacuum box system should
take ~2 h
1323 The sample test source preparation step takes ~075 h
1324 A four-hour counting time should be sufficient to meet the MQOs listed in
Step 14 assuming detector efficiency of 015ndash03 and radiochemical yield
of at least 05 A different counting time may be necessary to meet these
MQOs if any of the relevant parameters are significantly different
1325 Data should be ready for reduction ~8-9 h after beginning of analysis
14 Pollution Prevention The method utilizes small volume (2 mL) extraction chromatographic
resin columns This approach leads to a significant reduction in the volumes of load rinse
and strip solutions as compared to classical methods using ion exchange resins to separate
and purify the curium fraction
15 Waste Management
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 17 Revision 0
151 Types of waste generated per sample analyzed
1511 Approximately 210 mL basic waste from the initial sample
preconcentration
1512 Approximately 65 mL of acidic waste from loading and rinsing the two
extraction columns will be generated
1513 Approximately 25 mL of acidic waste from the microprecipitation method
for source preparation will be generated The waste contains 1 mL of HF
and ~ 5 mL of ethanol
1514 TEVAreg
cartridge ndash ready for appropriate disposal
1515 DGA cartridge ndash ready for appropriate disposal
1516 These waste streams may contain low levels of 243
Am (added as tracer) 244
Cm (added to LCS) and other radionuclides as present in samples
152 Evaluate all waste streams according to disposal requirements by applicable
regulations
16 References
Cited References
161 EPA 2009 Method Validation Guide for Radiological Laboratories Participating in
Incident Response Activities Revision 0 Office of Air and Radiation Washington
104 Perform Continuing Instrument Quality Control Testing according to ASTM Standard
Practice D7282 Sections 20 21 and 24 ldquoContinuing Instrument Quality Control
Testingrdquo and ldquoQuality Control for Alpha Spectrometry Systemsrdquo (Reference 163)
11 Procedure
111 Rapid Curium Separation using TEVAreg and DGA Resins
NOTE This method addresses the analysis of soluble curium only Solid material if present must be
removed from the sample prior to aliquanting by filtering the unpreserved sample aliquant through a
045-μm filter The solid material may be screened for radioactivity or saved for potential future analysis
1111 Aliquanting and Preparation
11111 Aliquant 200 mL of sample into a 225-mL centrifuge tube
1 This helps minimize interference from alpha-emitting isotopes with potentially overlapping energies
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 10 Revision 0
11112 Aliquant a second 200 mL portion of one sample into a 225-mL
centrifuge tube as a sample duplicate
11113 Add 200 mL reagent water to an empty 225-mL centrifuge tube
as a reagent blank
11114 Add 200 mL reagent water to an empty 225-mL centrifuge tube
for the LCS
11115 Acidify each sample with concentrated HNO3 to a pH of less
than 20 by adding HNO3 This usually requires about 05 mL of
HNO3
11116 Add 10-40 dpm 244
Cm standard solution to the LCS centrifuge
tube following laboratory protocol
11117 Add 10-40 dpm 243
Am tracer to the blank LCS and sample and
sample duplicates following laboratory protocol
11118 Add 1 mL of 15 M Ca(NO3)2 3 mL of 32 M (NH4)2HPO4
solution and 2ndash3 drops of phenolphthalein indicator to each
centrifuge tube
11119 Slowly add concentrated NH4OH to each centrifuge tube with a
squeeze bottle Add enough NH4OH to reach a dark pink
phenolphthalein end point and form Ca3(PO4)2 precipitate Cap
and mix tubes and centrifuge at 2000 revolutions per minute
(rpm) or more for ~5 minutes
Note If a sample aliquant larger than 200 mL is needed the aliquant may be added to
a large beaker heated on a hot plate to near boiling with reagents added and allowed
to cool and settle After pouring off enough of the supernate the precipitate may be
transferred to a 225 mL tube rinsing the beaker well with water and centrifuged
111110 Decant supernatant solution and discard to waste
1112 Preparation of the Load Solution
11121 Dissolve the calcium phosphate precipitate with 15 mL of 3 M
HNO3 - 10 M Al(NO3)3 If the residue volume is large or if
residual solids remain an additional 5 mL may be needed to
obtain complete dissolution
11122 Add 05 mL of 15 M sulfamic acid to each sample Swirl to mix
NOTE If elevated levels of 237
Np are potentially present in the sample also add 05 mL
of 4 mgmL iron carrier to enhance neptunium (Np) reduction to Np4+
The addition of
ascorbic acid in the next step will convert Fe3+
to Fe2+
and ensure removal of Np on
TEVAreg Resin
11123 Add 125 mL of 15 M ascorbic acid to each sample Swirl to
mix Wait 3 minutes
NOTE Plutonium (Pu) if present will be adjusted to Pu4+
to ensure retention and
removal on TEVAreg Resin A small amount of brown fumes results from nitrite
reaction with sulfamic acid The solution should clear with swirling If the solution
does not clear (is still dark) an additional small volume of sodium nitrite may be
added to clear the solution
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 11 Revision 0
11124 Add 1 mL of 35 M NaNO2 to each sample Swirl to mix
NOTE The load solution nitrate concentration is increased after valence adjustment to
provide greater retention of Am and more effective elution of calcium ions on DGA
Resin
11125 Add 15 mL concentrated HNO3 to each sample and swirl to mix
NOTE The steps in this section were optimized for a commercially available filtration
system Other vacuum systems may be substituted here The cartridges may be set up
and conditioned with nitric acid so that they are ready for column loading just prior
to completion of the valence adjustment steps More than one vacuum box may be
used to increase throughput
1113 Set up TEVAreg and DGA cartridges on the vacuum box system
11131 Place the inner centrifuge tube rack (supplied with vacuum box)
into the vacuum box with the centrifuge tubes in the rack Place
the lid on the vacuum box system
11132 Place the yellow outer tips into all 24 openings of the lid of the
vacuum box Fit an inner white tip into each yellow tip
11133 For each sample assemble a TEVAreg and a DGA cartridge and
lock these onto the inner white tip (DGA cartridge below
TEVAreg
)
11134 Place reservoirs on the top end of the TEVAreg cartridge
11135 Seal unused openings on the vacuum box by inserting yellow
caps included with the vacuum box into unused white tips to
achieve a good seal during the separation Alternately plastic
tape can be used to seal the unused lid holes
11136 Turn the vacuum on and ensure proper fitting of the lid
11137 Add 5 mL of 3 M HNO3 to the column reservoir to precondition
the TEVAreg cartridges
11138 Adjust the vacuum to achieve a flow-rate of ~1 mLmin
IMPORTANT Unless the method specifies otherwise use a flow rate of ~ 1 mLmin
for load and strip solutions and ~ 2 -3 mLmin for rinse solutions
1114 TEVAreg
and DGA Resin Separation
11141 Transfer each solution from Step 11125 into the appropriate
reservoir Allow solution to pass through the stacked TEVAreg +
DGA cartridge at a flow rate of ~1 mLmin
11142 Add 5 mL of 6 M HNO3 to each tubebeaker as a rinse and
transfer each solution into the appropriate reservoir (the flow rate
can be adjusted to ~2 mLmin)
11143 Add a 5 mL rinse of 6 M HNO3 to each column (the flow rate
can be adjusted to ~2 mLmin)
11144 Turn off vacuum discard rinse solutions and remove reservoirs
and TEVAreg cartridges and discard Place new reservoirs on the
DGA cartridges
11145 Add a 20 mL rinse of 01 M HNO3 to each reservoir (flow rate
~1-2 mLmin)
NOTE The rinses with dilute nitric acid remove uranium while curium
and americium are retained Precipitation of uranium during
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 12 Revision 0
microprecipitation is inhibited by adding hydrogen peroxide to ensure
uranium is present as UO22+
11146 Add 15 mL of 3 M HNO3ndash025 M HF to each reservoir at ~1-2
mLmin to complex and remove Th from the DGA Resin
11147 Add 3 mL of 4 M HCl to each reservoir at ~1ndash2 mLmin to rinse
column of residual fluoride Once the HCl has passed through the
column quickly pulse the vacuum two or three times to
minimize the amount of residual HCl in the column prior to
proceeding
11148 Ensure that clean labeled plastic tubes are placed in the tube
rack under each cartridge For maximum removal of
interferences during elution also change connector tips prior to
CmAm elution
11149 Add 10 mL of 025 M HCl solution to elute curium and
americium from each cartridge reducing the flow rate to ~1
mLmin (or slightly slower)
111410 Set the curium fraction in the plastic tube aside for cerium
fluoride coprecipitation Step 112
111411 Discard the DGA cartridge
112 Preparation of the Sample Test Source
NOTE Instructions below describe preparation of a single sample test source (STS) Several
STSs can be prepared simultaneously if a multi-channel vacuum manifold system is available
1121 Pipet 100 microL of the cerium carrier solution into each tube
1122 Pipet 05 mL 30 wt H2O2 into each tube to prevent residual uranium from
precipitating
1123 Pipet 1 mL of concentrated HF into each tube
1124 Cap the tube and mix Allow samples sit for ~ 15 minutes before filtering
1125 Set up a filter apparatus to accommodate a 01-micron 25-mm membrane
filter on a microprecipitation filtering apparatus
Caution Following deposition of the microprecipitate there is no visible difference
between the two sides of the filter
1126 If a hydrophobic filter is used add a few drops of 95 ethanol to wet each
filter and apply vacuum Ensure that there are no leaks along the sides
before proceeding
1127 While vacuum is applied add 2-3 mL of filtered Type I water to each filter
and allow the liquid to drain
1128 Add the sample to the reservoir rinsing the sample tubes with ~3 mL of
water and transfer this rinse to filter apparatus Allow to drain
1129 Wash each filter with ~2-3 mL of water and allow to drain
11210 Wash each filter with ~1-2 mL of 95 ethanol to displace water
11211 Allow to drain completely before turning the vacuum off
11212 Mount the filter on a labeled adhesive mounting disk (or equivalent)
ensuring that the filter is not wrinkled and is centered on the mounting disk
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 13 Revision 0
11213 Place the filter under a heat lamp for approximately 5 minutes or longer
until it is completely dry
11214 Count filters for an appropriate period of time by alpha spectrometry
11215 Discard the filtrate to waste for future disposal If the filtrate is to be
retained it should be stored in a plastic container since glass will be
attacked by HF
NOTE Other methods for STS preparation such as electrodeposition or
microprecipitation with neodymium fluoride may be used in lieu of the cerium
fluoride microprecipitation but any such substitution must be validated as described
in Step 15
12 Data Analysis and Calculations
121 Equations for activity concentration combined standard uncertainty and
radiochemical yield (if required)
1211 The activity concentration of the analyte and its combined standard
uncertainty are calculated using the following equations
aata
ttata
IDRV
IDRAAC
2
t
t
2
2
a
a
2
2
t
t
22
a2
a
2
a
2
t
2
a
2
t
2
t
2
ta
2
ac
)()()()()(
R
Ru
V
Vu
A
AuAC
IDRV
IDARuACu
ttt
tD
e
aat
aD
e
Where
ACa = activity concentration of the analyte at time of collection (or other
specified reference time) in picocuries per liter (pCiL)
At = activity of the tracer added to the sample aliquant on the tracer
solution reference datetime (pCi)
Ra = net count rate of the analyte in the defined region of interest (ROI)
in counts per second (see 1212)
Rt = net count rate of the tracer in the defined ROI in counts per second
(see 1212)
Va = volume of the sample aliquant (L)
Dt = correction factor for decay of the tracer from its reference date and
time to the midpoint of the counting period
Da = correction factor for decay of the analyte from the time of sample
collection (or other reference time) to the midpoint of the counting
period
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 14 Revision 0
It = probability of α emission in the defined ROI per decay of the tracer
(Table 171)
Ia = probability of α emission in the defined ROI per decay of the analyte
(Table 171)
uc(ACa) = combined standard uncertainty of the activity concentration of the
analyte (pCiL)
u(At) = standard uncertainty of the activity of the tracer added to the sample
(pCi)
u(Ra) = standard uncertainty of the net count rate of the analyte (sminus1
) (see
1212)
u(Rt) = standard uncertainty of the net count rate of the tracer (sminus1
) (see
1212)
u(Va) = standard uncertainty of the size of the sample aliquant volume (L)
λt = decay constant for the tracer radionuclide (sminus1
see Table 171)
λa = decay constant for the analyte radionuclide (sminus1
see Table 171)
tt = time elapsed between the activity reference date for the tracer and
the midpoint of the sample count (s)
ta = time elapsed between the activity reference date for the sample (eg
collection date) and the midpoint of the sample count (s)
NOTE The uncertainties of the decay-correction factors and of the probability of decay
factors are assumed to be negligible
NOTE The equation for the combined standard uncertainty (uc(ACa)) calculation is arranged to
eliminate the possibility of dividing by zero if Ra = 0
NOTE The standard uncertainty of the activity of the tracer added to the sample must reflect the
uncertainty associated with the activity of the standard reference material and any other
significant sources of uncertainty such as those introduced during the preparation of the tracer
solution (eg weighing or dilution factors) and during the process of adding the tracer to the
sample
1212 The net count rate of an analyte or tracer and its standard uncertainty are
calculated using the following equations
b
bx
s
xx
t
C
t
CR
and
2
b
bx
2
s
xx
11)(
t
C
t
CRu
where
Rx = net count rate of analyte or tracer in counts per second
Cx = sample counts in the analyte or the tracer ROI
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 15 Revision 0
ts = sample count time (s)
Cbx = background counts in the same ROI as for x
tb = background count time (s)
u(Rx) = standard uncertainty of the net count rate of tracer or analyte in
counts per second2
If the radiochemical yield of the tracer is requested the yield and its combined
standard uncertainty can be calculated using the following equations
ttt
t
0370 IDA
RRY
and
2
2
2
t
t
2
2
t
t
2)()()(
)(
u
A
Au
R
RuRYRYuc
where
RY = radiochemical yield of the tracer expressed as a fraction
Rt = net count rate of the tracer in counts per second
At = activity of the tracer added to the sample (pCi)
Dt = correction factor for decay of the tracer from its reference date and
time to the midpoint of the counting period
It = probability of α emission in the defined ROI per decay of the tracer
(Table 171)
ε = detector efficiency expressed as a fraction
uc(RY) = combined standard uncertainty of the radiochemical yield
u(Rt) = standard uncertainty of the net count rate of the tracer in counts per
second
u(At) = standard uncertainty of the activity of the tracer added to the sample
(pCi)
u(ε) = standard uncertainty of the detector efficiency
1213 If the critical level concentration (Lc) or the minimum detectable
concentration (MDC) are requested (at an error rate of 5) they can be
calculated using the following equations 3
2 For methods with very low counts MARLAP Section 19522 recommends adding one count each to the gross
counts and the background counts when estimating the uncertainty of the respective net counts This minimizes
negative bias in the estimate of uncertainty and protects against calculating zero uncertainty when a total of zero
counts are observed for the sample and background 3 The formulations for the critical level and minimum detectable concentration are based on the Stapleton
Approximation as recommended in MARLAP Section 20A22 Equations 2054 and 20A32 and Equation 2074
respectively (EPA 2004) The formulations presented here assume an error rate of α = 005 β = 005 (with z1minusα =
z1minusβ = 1645) and d = 04 For methods with very low numbers of counts these expressions provide better estimates
than do the traditional formulas for the critical level and MDC
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 16 Revision 0
aatas
ttt
b
s
b
sbba
b
s
b
s
cIDRVt
IDAt
t
t
ttR
t
t
t
t
L
140645116770140
aatas
ttt
b
ssba
b
s 13291271
MDCIDRVt
IDAt
ttR
t
t
where
Rba = background count rate for the analyte in the defined ROI in counts
per second
122 Results Reporting
1221 The following data should be reported for each result volume of sample
used yield of tracer and its uncertainty and FWHM of each peak used in
the analysis
1222 The following conventions should be used for each result
12221 Result in scientific notation plusmn combined standard uncertainty
13 Method Performance
131 Method validation results performed prior to analyzing samples are to be documented
and reported as required
132 Expected processing time per batch of 10-20 samples plus QC
1321 For an analysis of a 02 L sample aliquant precipitation and preparation of
load solution takes ~1 h
1322 Purification and separation using cartridges and vacuum box system should
take ~2 h
1323 The sample test source preparation step takes ~075 h
1324 A four-hour counting time should be sufficient to meet the MQOs listed in
Step 14 assuming detector efficiency of 015ndash03 and radiochemical yield
of at least 05 A different counting time may be necessary to meet these
MQOs if any of the relevant parameters are significantly different
1325 Data should be ready for reduction ~8-9 h after beginning of analysis
14 Pollution Prevention The method utilizes small volume (2 mL) extraction chromatographic
resin columns This approach leads to a significant reduction in the volumes of load rinse
and strip solutions as compared to classical methods using ion exchange resins to separate
and purify the curium fraction
15 Waste Management
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 17 Revision 0
151 Types of waste generated per sample analyzed
1511 Approximately 210 mL basic waste from the initial sample
preconcentration
1512 Approximately 65 mL of acidic waste from loading and rinsing the two
extraction columns will be generated
1513 Approximately 25 mL of acidic waste from the microprecipitation method
for source preparation will be generated The waste contains 1 mL of HF
and ~ 5 mL of ethanol
1514 TEVAreg
cartridge ndash ready for appropriate disposal
1515 DGA cartridge ndash ready for appropriate disposal
1516 These waste streams may contain low levels of 243
Am (added as tracer) 244
Cm (added to LCS) and other radionuclides as present in samples
152 Evaluate all waste streams according to disposal requirements by applicable
regulations
16 References
Cited References
161 EPA 2009 Method Validation Guide for Radiological Laboratories Participating in
Incident Response Activities Revision 0 Office of Air and Radiation Washington
104 Perform Continuing Instrument Quality Control Testing according to ASTM Standard
Practice D7282 Sections 20 21 and 24 ldquoContinuing Instrument Quality Control
Testingrdquo and ldquoQuality Control for Alpha Spectrometry Systemsrdquo (Reference 163)
11 Procedure
111 Rapid Curium Separation using TEVAreg and DGA Resins
NOTE This method addresses the analysis of soluble curium only Solid material if present must be
removed from the sample prior to aliquanting by filtering the unpreserved sample aliquant through a
045-μm filter The solid material may be screened for radioactivity or saved for potential future analysis
1111 Aliquanting and Preparation
11111 Aliquant 200 mL of sample into a 225-mL centrifuge tube
1 This helps minimize interference from alpha-emitting isotopes with potentially overlapping energies
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 10 Revision 0
11112 Aliquant a second 200 mL portion of one sample into a 225-mL
centrifuge tube as a sample duplicate
11113 Add 200 mL reagent water to an empty 225-mL centrifuge tube
as a reagent blank
11114 Add 200 mL reagent water to an empty 225-mL centrifuge tube
for the LCS
11115 Acidify each sample with concentrated HNO3 to a pH of less
than 20 by adding HNO3 This usually requires about 05 mL of
HNO3
11116 Add 10-40 dpm 244
Cm standard solution to the LCS centrifuge
tube following laboratory protocol
11117 Add 10-40 dpm 243
Am tracer to the blank LCS and sample and
sample duplicates following laboratory protocol
11118 Add 1 mL of 15 M Ca(NO3)2 3 mL of 32 M (NH4)2HPO4
solution and 2ndash3 drops of phenolphthalein indicator to each
centrifuge tube
11119 Slowly add concentrated NH4OH to each centrifuge tube with a
squeeze bottle Add enough NH4OH to reach a dark pink
phenolphthalein end point and form Ca3(PO4)2 precipitate Cap
and mix tubes and centrifuge at 2000 revolutions per minute
(rpm) or more for ~5 minutes
Note If a sample aliquant larger than 200 mL is needed the aliquant may be added to
a large beaker heated on a hot plate to near boiling with reagents added and allowed
to cool and settle After pouring off enough of the supernate the precipitate may be
transferred to a 225 mL tube rinsing the beaker well with water and centrifuged
111110 Decant supernatant solution and discard to waste
1112 Preparation of the Load Solution
11121 Dissolve the calcium phosphate precipitate with 15 mL of 3 M
HNO3 - 10 M Al(NO3)3 If the residue volume is large or if
residual solids remain an additional 5 mL may be needed to
obtain complete dissolution
11122 Add 05 mL of 15 M sulfamic acid to each sample Swirl to mix
NOTE If elevated levels of 237
Np are potentially present in the sample also add 05 mL
of 4 mgmL iron carrier to enhance neptunium (Np) reduction to Np4+
The addition of
ascorbic acid in the next step will convert Fe3+
to Fe2+
and ensure removal of Np on
TEVAreg Resin
11123 Add 125 mL of 15 M ascorbic acid to each sample Swirl to
mix Wait 3 minutes
NOTE Plutonium (Pu) if present will be adjusted to Pu4+
to ensure retention and
removal on TEVAreg Resin A small amount of brown fumes results from nitrite
reaction with sulfamic acid The solution should clear with swirling If the solution
does not clear (is still dark) an additional small volume of sodium nitrite may be
added to clear the solution
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 11 Revision 0
11124 Add 1 mL of 35 M NaNO2 to each sample Swirl to mix
NOTE The load solution nitrate concentration is increased after valence adjustment to
provide greater retention of Am and more effective elution of calcium ions on DGA
Resin
11125 Add 15 mL concentrated HNO3 to each sample and swirl to mix
NOTE The steps in this section were optimized for a commercially available filtration
system Other vacuum systems may be substituted here The cartridges may be set up
and conditioned with nitric acid so that they are ready for column loading just prior
to completion of the valence adjustment steps More than one vacuum box may be
used to increase throughput
1113 Set up TEVAreg and DGA cartridges on the vacuum box system
11131 Place the inner centrifuge tube rack (supplied with vacuum box)
into the vacuum box with the centrifuge tubes in the rack Place
the lid on the vacuum box system
11132 Place the yellow outer tips into all 24 openings of the lid of the
vacuum box Fit an inner white tip into each yellow tip
11133 For each sample assemble a TEVAreg and a DGA cartridge and
lock these onto the inner white tip (DGA cartridge below
TEVAreg
)
11134 Place reservoirs on the top end of the TEVAreg cartridge
11135 Seal unused openings on the vacuum box by inserting yellow
caps included with the vacuum box into unused white tips to
achieve a good seal during the separation Alternately plastic
tape can be used to seal the unused lid holes
11136 Turn the vacuum on and ensure proper fitting of the lid
11137 Add 5 mL of 3 M HNO3 to the column reservoir to precondition
the TEVAreg cartridges
11138 Adjust the vacuum to achieve a flow-rate of ~1 mLmin
IMPORTANT Unless the method specifies otherwise use a flow rate of ~ 1 mLmin
for load and strip solutions and ~ 2 -3 mLmin for rinse solutions
1114 TEVAreg
and DGA Resin Separation
11141 Transfer each solution from Step 11125 into the appropriate
reservoir Allow solution to pass through the stacked TEVAreg +
DGA cartridge at a flow rate of ~1 mLmin
11142 Add 5 mL of 6 M HNO3 to each tubebeaker as a rinse and
transfer each solution into the appropriate reservoir (the flow rate
can be adjusted to ~2 mLmin)
11143 Add a 5 mL rinse of 6 M HNO3 to each column (the flow rate
can be adjusted to ~2 mLmin)
11144 Turn off vacuum discard rinse solutions and remove reservoirs
and TEVAreg cartridges and discard Place new reservoirs on the
DGA cartridges
11145 Add a 20 mL rinse of 01 M HNO3 to each reservoir (flow rate
~1-2 mLmin)
NOTE The rinses with dilute nitric acid remove uranium while curium
and americium are retained Precipitation of uranium during
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 12 Revision 0
microprecipitation is inhibited by adding hydrogen peroxide to ensure
uranium is present as UO22+
11146 Add 15 mL of 3 M HNO3ndash025 M HF to each reservoir at ~1-2
mLmin to complex and remove Th from the DGA Resin
11147 Add 3 mL of 4 M HCl to each reservoir at ~1ndash2 mLmin to rinse
column of residual fluoride Once the HCl has passed through the
column quickly pulse the vacuum two or three times to
minimize the amount of residual HCl in the column prior to
proceeding
11148 Ensure that clean labeled plastic tubes are placed in the tube
rack under each cartridge For maximum removal of
interferences during elution also change connector tips prior to
CmAm elution
11149 Add 10 mL of 025 M HCl solution to elute curium and
americium from each cartridge reducing the flow rate to ~1
mLmin (or slightly slower)
111410 Set the curium fraction in the plastic tube aside for cerium
fluoride coprecipitation Step 112
111411 Discard the DGA cartridge
112 Preparation of the Sample Test Source
NOTE Instructions below describe preparation of a single sample test source (STS) Several
STSs can be prepared simultaneously if a multi-channel vacuum manifold system is available
1121 Pipet 100 microL of the cerium carrier solution into each tube
1122 Pipet 05 mL 30 wt H2O2 into each tube to prevent residual uranium from
precipitating
1123 Pipet 1 mL of concentrated HF into each tube
1124 Cap the tube and mix Allow samples sit for ~ 15 minutes before filtering
1125 Set up a filter apparatus to accommodate a 01-micron 25-mm membrane
filter on a microprecipitation filtering apparatus
Caution Following deposition of the microprecipitate there is no visible difference
between the two sides of the filter
1126 If a hydrophobic filter is used add a few drops of 95 ethanol to wet each
filter and apply vacuum Ensure that there are no leaks along the sides
before proceeding
1127 While vacuum is applied add 2-3 mL of filtered Type I water to each filter
and allow the liquid to drain
1128 Add the sample to the reservoir rinsing the sample tubes with ~3 mL of
water and transfer this rinse to filter apparatus Allow to drain
1129 Wash each filter with ~2-3 mL of water and allow to drain
11210 Wash each filter with ~1-2 mL of 95 ethanol to displace water
11211 Allow to drain completely before turning the vacuum off
11212 Mount the filter on a labeled adhesive mounting disk (or equivalent)
ensuring that the filter is not wrinkled and is centered on the mounting disk
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 13 Revision 0
11213 Place the filter under a heat lamp for approximately 5 minutes or longer
until it is completely dry
11214 Count filters for an appropriate period of time by alpha spectrometry
11215 Discard the filtrate to waste for future disposal If the filtrate is to be
retained it should be stored in a plastic container since glass will be
attacked by HF
NOTE Other methods for STS preparation such as electrodeposition or
microprecipitation with neodymium fluoride may be used in lieu of the cerium
fluoride microprecipitation but any such substitution must be validated as described
in Step 15
12 Data Analysis and Calculations
121 Equations for activity concentration combined standard uncertainty and
radiochemical yield (if required)
1211 The activity concentration of the analyte and its combined standard
uncertainty are calculated using the following equations
aata
ttata
IDRV
IDRAAC
2
t
t
2
2
a
a
2
2
t
t
22
a2
a
2
a
2
t
2
a
2
t
2
t
2
ta
2
ac
)()()()()(
R
Ru
V
Vu
A
AuAC
IDRV
IDARuACu
ttt
tD
e
aat
aD
e
Where
ACa = activity concentration of the analyte at time of collection (or other
specified reference time) in picocuries per liter (pCiL)
At = activity of the tracer added to the sample aliquant on the tracer
solution reference datetime (pCi)
Ra = net count rate of the analyte in the defined region of interest (ROI)
in counts per second (see 1212)
Rt = net count rate of the tracer in the defined ROI in counts per second
(see 1212)
Va = volume of the sample aliquant (L)
Dt = correction factor for decay of the tracer from its reference date and
time to the midpoint of the counting period
Da = correction factor for decay of the analyte from the time of sample
collection (or other reference time) to the midpoint of the counting
period
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 14 Revision 0
It = probability of α emission in the defined ROI per decay of the tracer
(Table 171)
Ia = probability of α emission in the defined ROI per decay of the analyte
(Table 171)
uc(ACa) = combined standard uncertainty of the activity concentration of the
analyte (pCiL)
u(At) = standard uncertainty of the activity of the tracer added to the sample
(pCi)
u(Ra) = standard uncertainty of the net count rate of the analyte (sminus1
) (see
1212)
u(Rt) = standard uncertainty of the net count rate of the tracer (sminus1
) (see
1212)
u(Va) = standard uncertainty of the size of the sample aliquant volume (L)
λt = decay constant for the tracer radionuclide (sminus1
see Table 171)
λa = decay constant for the analyte radionuclide (sminus1
see Table 171)
tt = time elapsed between the activity reference date for the tracer and
the midpoint of the sample count (s)
ta = time elapsed between the activity reference date for the sample (eg
collection date) and the midpoint of the sample count (s)
NOTE The uncertainties of the decay-correction factors and of the probability of decay
factors are assumed to be negligible
NOTE The equation for the combined standard uncertainty (uc(ACa)) calculation is arranged to
eliminate the possibility of dividing by zero if Ra = 0
NOTE The standard uncertainty of the activity of the tracer added to the sample must reflect the
uncertainty associated with the activity of the standard reference material and any other
significant sources of uncertainty such as those introduced during the preparation of the tracer
solution (eg weighing or dilution factors) and during the process of adding the tracer to the
sample
1212 The net count rate of an analyte or tracer and its standard uncertainty are
calculated using the following equations
b
bx
s
xx
t
C
t
CR
and
2
b
bx
2
s
xx
11)(
t
C
t
CRu
where
Rx = net count rate of analyte or tracer in counts per second
Cx = sample counts in the analyte or the tracer ROI
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 15 Revision 0
ts = sample count time (s)
Cbx = background counts in the same ROI as for x
tb = background count time (s)
u(Rx) = standard uncertainty of the net count rate of tracer or analyte in
counts per second2
If the radiochemical yield of the tracer is requested the yield and its combined
standard uncertainty can be calculated using the following equations
ttt
t
0370 IDA
RRY
and
2
2
2
t
t
2
2
t
t
2)()()(
)(
u
A
Au
R
RuRYRYuc
where
RY = radiochemical yield of the tracer expressed as a fraction
Rt = net count rate of the tracer in counts per second
At = activity of the tracer added to the sample (pCi)
Dt = correction factor for decay of the tracer from its reference date and
time to the midpoint of the counting period
It = probability of α emission in the defined ROI per decay of the tracer
(Table 171)
ε = detector efficiency expressed as a fraction
uc(RY) = combined standard uncertainty of the radiochemical yield
u(Rt) = standard uncertainty of the net count rate of the tracer in counts per
second
u(At) = standard uncertainty of the activity of the tracer added to the sample
(pCi)
u(ε) = standard uncertainty of the detector efficiency
1213 If the critical level concentration (Lc) or the minimum detectable
concentration (MDC) are requested (at an error rate of 5) they can be
calculated using the following equations 3
2 For methods with very low counts MARLAP Section 19522 recommends adding one count each to the gross
counts and the background counts when estimating the uncertainty of the respective net counts This minimizes
negative bias in the estimate of uncertainty and protects against calculating zero uncertainty when a total of zero
counts are observed for the sample and background 3 The formulations for the critical level and minimum detectable concentration are based on the Stapleton
Approximation as recommended in MARLAP Section 20A22 Equations 2054 and 20A32 and Equation 2074
respectively (EPA 2004) The formulations presented here assume an error rate of α = 005 β = 005 (with z1minusα =
z1minusβ = 1645) and d = 04 For methods with very low numbers of counts these expressions provide better estimates
than do the traditional formulas for the critical level and MDC
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 16 Revision 0
aatas
ttt
b
s
b
sbba
b
s
b
s
cIDRVt
IDAt
t
t
ttR
t
t
t
t
L
140645116770140
aatas
ttt
b
ssba
b
s 13291271
MDCIDRVt
IDAt
ttR
t
t
where
Rba = background count rate for the analyte in the defined ROI in counts
per second
122 Results Reporting
1221 The following data should be reported for each result volume of sample
used yield of tracer and its uncertainty and FWHM of each peak used in
the analysis
1222 The following conventions should be used for each result
12221 Result in scientific notation plusmn combined standard uncertainty
13 Method Performance
131 Method validation results performed prior to analyzing samples are to be documented
and reported as required
132 Expected processing time per batch of 10-20 samples plus QC
1321 For an analysis of a 02 L sample aliquant precipitation and preparation of
load solution takes ~1 h
1322 Purification and separation using cartridges and vacuum box system should
take ~2 h
1323 The sample test source preparation step takes ~075 h
1324 A four-hour counting time should be sufficient to meet the MQOs listed in
Step 14 assuming detector efficiency of 015ndash03 and radiochemical yield
of at least 05 A different counting time may be necessary to meet these
MQOs if any of the relevant parameters are significantly different
1325 Data should be ready for reduction ~8-9 h after beginning of analysis
14 Pollution Prevention The method utilizes small volume (2 mL) extraction chromatographic
resin columns This approach leads to a significant reduction in the volumes of load rinse
and strip solutions as compared to classical methods using ion exchange resins to separate
and purify the curium fraction
15 Waste Management
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 17 Revision 0
151 Types of waste generated per sample analyzed
1511 Approximately 210 mL basic waste from the initial sample
preconcentration
1512 Approximately 65 mL of acidic waste from loading and rinsing the two
extraction columns will be generated
1513 Approximately 25 mL of acidic waste from the microprecipitation method
for source preparation will be generated The waste contains 1 mL of HF
and ~ 5 mL of ethanol
1514 TEVAreg
cartridge ndash ready for appropriate disposal
1515 DGA cartridge ndash ready for appropriate disposal
1516 These waste streams may contain low levels of 243
Am (added as tracer) 244
Cm (added to LCS) and other radionuclides as present in samples
152 Evaluate all waste streams according to disposal requirements by applicable
regulations
16 References
Cited References
161 EPA 2009 Method Validation Guide for Radiological Laboratories Participating in
Incident Response Activities Revision 0 Office of Air and Radiation Washington
104 Perform Continuing Instrument Quality Control Testing according to ASTM Standard
Practice D7282 Sections 20 21 and 24 ldquoContinuing Instrument Quality Control
Testingrdquo and ldquoQuality Control for Alpha Spectrometry Systemsrdquo (Reference 163)
11 Procedure
111 Rapid Curium Separation using TEVAreg and DGA Resins
NOTE This method addresses the analysis of soluble curium only Solid material if present must be
removed from the sample prior to aliquanting by filtering the unpreserved sample aliquant through a
045-μm filter The solid material may be screened for radioactivity or saved for potential future analysis
1111 Aliquanting and Preparation
11111 Aliquant 200 mL of sample into a 225-mL centrifuge tube
1 This helps minimize interference from alpha-emitting isotopes with potentially overlapping energies
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 10 Revision 0
11112 Aliquant a second 200 mL portion of one sample into a 225-mL
centrifuge tube as a sample duplicate
11113 Add 200 mL reagent water to an empty 225-mL centrifuge tube
as a reagent blank
11114 Add 200 mL reagent water to an empty 225-mL centrifuge tube
for the LCS
11115 Acidify each sample with concentrated HNO3 to a pH of less
than 20 by adding HNO3 This usually requires about 05 mL of
HNO3
11116 Add 10-40 dpm 244
Cm standard solution to the LCS centrifuge
tube following laboratory protocol
11117 Add 10-40 dpm 243
Am tracer to the blank LCS and sample and
sample duplicates following laboratory protocol
11118 Add 1 mL of 15 M Ca(NO3)2 3 mL of 32 M (NH4)2HPO4
solution and 2ndash3 drops of phenolphthalein indicator to each
centrifuge tube
11119 Slowly add concentrated NH4OH to each centrifuge tube with a
squeeze bottle Add enough NH4OH to reach a dark pink
phenolphthalein end point and form Ca3(PO4)2 precipitate Cap
and mix tubes and centrifuge at 2000 revolutions per minute
(rpm) or more for ~5 minutes
Note If a sample aliquant larger than 200 mL is needed the aliquant may be added to
a large beaker heated on a hot plate to near boiling with reagents added and allowed
to cool and settle After pouring off enough of the supernate the precipitate may be
transferred to a 225 mL tube rinsing the beaker well with water and centrifuged
111110 Decant supernatant solution and discard to waste
1112 Preparation of the Load Solution
11121 Dissolve the calcium phosphate precipitate with 15 mL of 3 M
HNO3 - 10 M Al(NO3)3 If the residue volume is large or if
residual solids remain an additional 5 mL may be needed to
obtain complete dissolution
11122 Add 05 mL of 15 M sulfamic acid to each sample Swirl to mix
NOTE If elevated levels of 237
Np are potentially present in the sample also add 05 mL
of 4 mgmL iron carrier to enhance neptunium (Np) reduction to Np4+
The addition of
ascorbic acid in the next step will convert Fe3+
to Fe2+
and ensure removal of Np on
TEVAreg Resin
11123 Add 125 mL of 15 M ascorbic acid to each sample Swirl to
mix Wait 3 minutes
NOTE Plutonium (Pu) if present will be adjusted to Pu4+
to ensure retention and
removal on TEVAreg Resin A small amount of brown fumes results from nitrite
reaction with sulfamic acid The solution should clear with swirling If the solution
does not clear (is still dark) an additional small volume of sodium nitrite may be
added to clear the solution
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 11 Revision 0
11124 Add 1 mL of 35 M NaNO2 to each sample Swirl to mix
NOTE The load solution nitrate concentration is increased after valence adjustment to
provide greater retention of Am and more effective elution of calcium ions on DGA
Resin
11125 Add 15 mL concentrated HNO3 to each sample and swirl to mix
NOTE The steps in this section were optimized for a commercially available filtration
system Other vacuum systems may be substituted here The cartridges may be set up
and conditioned with nitric acid so that they are ready for column loading just prior
to completion of the valence adjustment steps More than one vacuum box may be
used to increase throughput
1113 Set up TEVAreg and DGA cartridges on the vacuum box system
11131 Place the inner centrifuge tube rack (supplied with vacuum box)
into the vacuum box with the centrifuge tubes in the rack Place
the lid on the vacuum box system
11132 Place the yellow outer tips into all 24 openings of the lid of the
vacuum box Fit an inner white tip into each yellow tip
11133 For each sample assemble a TEVAreg and a DGA cartridge and
lock these onto the inner white tip (DGA cartridge below
TEVAreg
)
11134 Place reservoirs on the top end of the TEVAreg cartridge
11135 Seal unused openings on the vacuum box by inserting yellow
caps included with the vacuum box into unused white tips to
achieve a good seal during the separation Alternately plastic
tape can be used to seal the unused lid holes
11136 Turn the vacuum on and ensure proper fitting of the lid
11137 Add 5 mL of 3 M HNO3 to the column reservoir to precondition
the TEVAreg cartridges
11138 Adjust the vacuum to achieve a flow-rate of ~1 mLmin
IMPORTANT Unless the method specifies otherwise use a flow rate of ~ 1 mLmin
for load and strip solutions and ~ 2 -3 mLmin for rinse solutions
1114 TEVAreg
and DGA Resin Separation
11141 Transfer each solution from Step 11125 into the appropriate
reservoir Allow solution to pass through the stacked TEVAreg +
DGA cartridge at a flow rate of ~1 mLmin
11142 Add 5 mL of 6 M HNO3 to each tubebeaker as a rinse and
transfer each solution into the appropriate reservoir (the flow rate
can be adjusted to ~2 mLmin)
11143 Add a 5 mL rinse of 6 M HNO3 to each column (the flow rate
can be adjusted to ~2 mLmin)
11144 Turn off vacuum discard rinse solutions and remove reservoirs
and TEVAreg cartridges and discard Place new reservoirs on the
DGA cartridges
11145 Add a 20 mL rinse of 01 M HNO3 to each reservoir (flow rate
~1-2 mLmin)
NOTE The rinses with dilute nitric acid remove uranium while curium
and americium are retained Precipitation of uranium during
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 12 Revision 0
microprecipitation is inhibited by adding hydrogen peroxide to ensure
uranium is present as UO22+
11146 Add 15 mL of 3 M HNO3ndash025 M HF to each reservoir at ~1-2
mLmin to complex and remove Th from the DGA Resin
11147 Add 3 mL of 4 M HCl to each reservoir at ~1ndash2 mLmin to rinse
column of residual fluoride Once the HCl has passed through the
column quickly pulse the vacuum two or three times to
minimize the amount of residual HCl in the column prior to
proceeding
11148 Ensure that clean labeled plastic tubes are placed in the tube
rack under each cartridge For maximum removal of
interferences during elution also change connector tips prior to
CmAm elution
11149 Add 10 mL of 025 M HCl solution to elute curium and
americium from each cartridge reducing the flow rate to ~1
mLmin (or slightly slower)
111410 Set the curium fraction in the plastic tube aside for cerium
fluoride coprecipitation Step 112
111411 Discard the DGA cartridge
112 Preparation of the Sample Test Source
NOTE Instructions below describe preparation of a single sample test source (STS) Several
STSs can be prepared simultaneously if a multi-channel vacuum manifold system is available
1121 Pipet 100 microL of the cerium carrier solution into each tube
1122 Pipet 05 mL 30 wt H2O2 into each tube to prevent residual uranium from
precipitating
1123 Pipet 1 mL of concentrated HF into each tube
1124 Cap the tube and mix Allow samples sit for ~ 15 minutes before filtering
1125 Set up a filter apparatus to accommodate a 01-micron 25-mm membrane
filter on a microprecipitation filtering apparatus
Caution Following deposition of the microprecipitate there is no visible difference
between the two sides of the filter
1126 If a hydrophobic filter is used add a few drops of 95 ethanol to wet each
filter and apply vacuum Ensure that there are no leaks along the sides
before proceeding
1127 While vacuum is applied add 2-3 mL of filtered Type I water to each filter
and allow the liquid to drain
1128 Add the sample to the reservoir rinsing the sample tubes with ~3 mL of
water and transfer this rinse to filter apparatus Allow to drain
1129 Wash each filter with ~2-3 mL of water and allow to drain
11210 Wash each filter with ~1-2 mL of 95 ethanol to displace water
11211 Allow to drain completely before turning the vacuum off
11212 Mount the filter on a labeled adhesive mounting disk (or equivalent)
ensuring that the filter is not wrinkled and is centered on the mounting disk
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 13 Revision 0
11213 Place the filter under a heat lamp for approximately 5 minutes or longer
until it is completely dry
11214 Count filters for an appropriate period of time by alpha spectrometry
11215 Discard the filtrate to waste for future disposal If the filtrate is to be
retained it should be stored in a plastic container since glass will be
attacked by HF
NOTE Other methods for STS preparation such as electrodeposition or
microprecipitation with neodymium fluoride may be used in lieu of the cerium
fluoride microprecipitation but any such substitution must be validated as described
in Step 15
12 Data Analysis and Calculations
121 Equations for activity concentration combined standard uncertainty and
radiochemical yield (if required)
1211 The activity concentration of the analyte and its combined standard
uncertainty are calculated using the following equations
aata
ttata
IDRV
IDRAAC
2
t
t
2
2
a
a
2
2
t
t
22
a2
a
2
a
2
t
2
a
2
t
2
t
2
ta
2
ac
)()()()()(
R
Ru
V
Vu
A
AuAC
IDRV
IDARuACu
ttt
tD
e
aat
aD
e
Where
ACa = activity concentration of the analyte at time of collection (or other
specified reference time) in picocuries per liter (pCiL)
At = activity of the tracer added to the sample aliquant on the tracer
solution reference datetime (pCi)
Ra = net count rate of the analyte in the defined region of interest (ROI)
in counts per second (see 1212)
Rt = net count rate of the tracer in the defined ROI in counts per second
(see 1212)
Va = volume of the sample aliquant (L)
Dt = correction factor for decay of the tracer from its reference date and
time to the midpoint of the counting period
Da = correction factor for decay of the analyte from the time of sample
collection (or other reference time) to the midpoint of the counting
period
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 14 Revision 0
It = probability of α emission in the defined ROI per decay of the tracer
(Table 171)
Ia = probability of α emission in the defined ROI per decay of the analyte
(Table 171)
uc(ACa) = combined standard uncertainty of the activity concentration of the
analyte (pCiL)
u(At) = standard uncertainty of the activity of the tracer added to the sample
(pCi)
u(Ra) = standard uncertainty of the net count rate of the analyte (sminus1
) (see
1212)
u(Rt) = standard uncertainty of the net count rate of the tracer (sminus1
) (see
1212)
u(Va) = standard uncertainty of the size of the sample aliquant volume (L)
λt = decay constant for the tracer radionuclide (sminus1
see Table 171)
λa = decay constant for the analyte radionuclide (sminus1
see Table 171)
tt = time elapsed between the activity reference date for the tracer and
the midpoint of the sample count (s)
ta = time elapsed between the activity reference date for the sample (eg
collection date) and the midpoint of the sample count (s)
NOTE The uncertainties of the decay-correction factors and of the probability of decay
factors are assumed to be negligible
NOTE The equation for the combined standard uncertainty (uc(ACa)) calculation is arranged to
eliminate the possibility of dividing by zero if Ra = 0
NOTE The standard uncertainty of the activity of the tracer added to the sample must reflect the
uncertainty associated with the activity of the standard reference material and any other
significant sources of uncertainty such as those introduced during the preparation of the tracer
solution (eg weighing or dilution factors) and during the process of adding the tracer to the
sample
1212 The net count rate of an analyte or tracer and its standard uncertainty are
calculated using the following equations
b
bx
s
xx
t
C
t
CR
and
2
b
bx
2
s
xx
11)(
t
C
t
CRu
where
Rx = net count rate of analyte or tracer in counts per second
Cx = sample counts in the analyte or the tracer ROI
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 15 Revision 0
ts = sample count time (s)
Cbx = background counts in the same ROI as for x
tb = background count time (s)
u(Rx) = standard uncertainty of the net count rate of tracer or analyte in
counts per second2
If the radiochemical yield of the tracer is requested the yield and its combined
standard uncertainty can be calculated using the following equations
ttt
t
0370 IDA
RRY
and
2
2
2
t
t
2
2
t
t
2)()()(
)(
u
A
Au
R
RuRYRYuc
where
RY = radiochemical yield of the tracer expressed as a fraction
Rt = net count rate of the tracer in counts per second
At = activity of the tracer added to the sample (pCi)
Dt = correction factor for decay of the tracer from its reference date and
time to the midpoint of the counting period
It = probability of α emission in the defined ROI per decay of the tracer
(Table 171)
ε = detector efficiency expressed as a fraction
uc(RY) = combined standard uncertainty of the radiochemical yield
u(Rt) = standard uncertainty of the net count rate of the tracer in counts per
second
u(At) = standard uncertainty of the activity of the tracer added to the sample
(pCi)
u(ε) = standard uncertainty of the detector efficiency
1213 If the critical level concentration (Lc) or the minimum detectable
concentration (MDC) are requested (at an error rate of 5) they can be
calculated using the following equations 3
2 For methods with very low counts MARLAP Section 19522 recommends adding one count each to the gross
counts and the background counts when estimating the uncertainty of the respective net counts This minimizes
negative bias in the estimate of uncertainty and protects against calculating zero uncertainty when a total of zero
counts are observed for the sample and background 3 The formulations for the critical level and minimum detectable concentration are based on the Stapleton
Approximation as recommended in MARLAP Section 20A22 Equations 2054 and 20A32 and Equation 2074
respectively (EPA 2004) The formulations presented here assume an error rate of α = 005 β = 005 (with z1minusα =
z1minusβ = 1645) and d = 04 For methods with very low numbers of counts these expressions provide better estimates
than do the traditional formulas for the critical level and MDC
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 16 Revision 0
aatas
ttt
b
s
b
sbba
b
s
b
s
cIDRVt
IDAt
t
t
ttR
t
t
t
t
L
140645116770140
aatas
ttt
b
ssba
b
s 13291271
MDCIDRVt
IDAt
ttR
t
t
where
Rba = background count rate for the analyte in the defined ROI in counts
per second
122 Results Reporting
1221 The following data should be reported for each result volume of sample
used yield of tracer and its uncertainty and FWHM of each peak used in
the analysis
1222 The following conventions should be used for each result
12221 Result in scientific notation plusmn combined standard uncertainty
13 Method Performance
131 Method validation results performed prior to analyzing samples are to be documented
and reported as required
132 Expected processing time per batch of 10-20 samples plus QC
1321 For an analysis of a 02 L sample aliquant precipitation and preparation of
load solution takes ~1 h
1322 Purification and separation using cartridges and vacuum box system should
take ~2 h
1323 The sample test source preparation step takes ~075 h
1324 A four-hour counting time should be sufficient to meet the MQOs listed in
Step 14 assuming detector efficiency of 015ndash03 and radiochemical yield
of at least 05 A different counting time may be necessary to meet these
MQOs if any of the relevant parameters are significantly different
1325 Data should be ready for reduction ~8-9 h after beginning of analysis
14 Pollution Prevention The method utilizes small volume (2 mL) extraction chromatographic
resin columns This approach leads to a significant reduction in the volumes of load rinse
and strip solutions as compared to classical methods using ion exchange resins to separate
and purify the curium fraction
15 Waste Management
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 17 Revision 0
151 Types of waste generated per sample analyzed
1511 Approximately 210 mL basic waste from the initial sample
preconcentration
1512 Approximately 65 mL of acidic waste from loading and rinsing the two
extraction columns will be generated
1513 Approximately 25 mL of acidic waste from the microprecipitation method
for source preparation will be generated The waste contains 1 mL of HF
and ~ 5 mL of ethanol
1514 TEVAreg
cartridge ndash ready for appropriate disposal
1515 DGA cartridge ndash ready for appropriate disposal
1516 These waste streams may contain low levels of 243
Am (added as tracer) 244
Cm (added to LCS) and other radionuclides as present in samples
152 Evaluate all waste streams according to disposal requirements by applicable
regulations
16 References
Cited References
161 EPA 2009 Method Validation Guide for Radiological Laboratories Participating in
Incident Response Activities Revision 0 Office of Air and Radiation Washington
104 Perform Continuing Instrument Quality Control Testing according to ASTM Standard
Practice D7282 Sections 20 21 and 24 ldquoContinuing Instrument Quality Control
Testingrdquo and ldquoQuality Control for Alpha Spectrometry Systemsrdquo (Reference 163)
11 Procedure
111 Rapid Curium Separation using TEVAreg and DGA Resins
NOTE This method addresses the analysis of soluble curium only Solid material if present must be
removed from the sample prior to aliquanting by filtering the unpreserved sample aliquant through a
045-μm filter The solid material may be screened for radioactivity or saved for potential future analysis
1111 Aliquanting and Preparation
11111 Aliquant 200 mL of sample into a 225-mL centrifuge tube
1 This helps minimize interference from alpha-emitting isotopes with potentially overlapping energies
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 10 Revision 0
11112 Aliquant a second 200 mL portion of one sample into a 225-mL
centrifuge tube as a sample duplicate
11113 Add 200 mL reagent water to an empty 225-mL centrifuge tube
as a reagent blank
11114 Add 200 mL reagent water to an empty 225-mL centrifuge tube
for the LCS
11115 Acidify each sample with concentrated HNO3 to a pH of less
than 20 by adding HNO3 This usually requires about 05 mL of
HNO3
11116 Add 10-40 dpm 244
Cm standard solution to the LCS centrifuge
tube following laboratory protocol
11117 Add 10-40 dpm 243
Am tracer to the blank LCS and sample and
sample duplicates following laboratory protocol
11118 Add 1 mL of 15 M Ca(NO3)2 3 mL of 32 M (NH4)2HPO4
solution and 2ndash3 drops of phenolphthalein indicator to each
centrifuge tube
11119 Slowly add concentrated NH4OH to each centrifuge tube with a
squeeze bottle Add enough NH4OH to reach a dark pink
phenolphthalein end point and form Ca3(PO4)2 precipitate Cap
and mix tubes and centrifuge at 2000 revolutions per minute
(rpm) or more for ~5 minutes
Note If a sample aliquant larger than 200 mL is needed the aliquant may be added to
a large beaker heated on a hot plate to near boiling with reagents added and allowed
to cool and settle After pouring off enough of the supernate the precipitate may be
transferred to a 225 mL tube rinsing the beaker well with water and centrifuged
111110 Decant supernatant solution and discard to waste
1112 Preparation of the Load Solution
11121 Dissolve the calcium phosphate precipitate with 15 mL of 3 M
HNO3 - 10 M Al(NO3)3 If the residue volume is large or if
residual solids remain an additional 5 mL may be needed to
obtain complete dissolution
11122 Add 05 mL of 15 M sulfamic acid to each sample Swirl to mix
NOTE If elevated levels of 237
Np are potentially present in the sample also add 05 mL
of 4 mgmL iron carrier to enhance neptunium (Np) reduction to Np4+
The addition of
ascorbic acid in the next step will convert Fe3+
to Fe2+
and ensure removal of Np on
TEVAreg Resin
11123 Add 125 mL of 15 M ascorbic acid to each sample Swirl to
mix Wait 3 minutes
NOTE Plutonium (Pu) if present will be adjusted to Pu4+
to ensure retention and
removal on TEVAreg Resin A small amount of brown fumes results from nitrite
reaction with sulfamic acid The solution should clear with swirling If the solution
does not clear (is still dark) an additional small volume of sodium nitrite may be
added to clear the solution
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 11 Revision 0
11124 Add 1 mL of 35 M NaNO2 to each sample Swirl to mix
NOTE The load solution nitrate concentration is increased after valence adjustment to
provide greater retention of Am and more effective elution of calcium ions on DGA
Resin
11125 Add 15 mL concentrated HNO3 to each sample and swirl to mix
NOTE The steps in this section were optimized for a commercially available filtration
system Other vacuum systems may be substituted here The cartridges may be set up
and conditioned with nitric acid so that they are ready for column loading just prior
to completion of the valence adjustment steps More than one vacuum box may be
used to increase throughput
1113 Set up TEVAreg and DGA cartridges on the vacuum box system
11131 Place the inner centrifuge tube rack (supplied with vacuum box)
into the vacuum box with the centrifuge tubes in the rack Place
the lid on the vacuum box system
11132 Place the yellow outer tips into all 24 openings of the lid of the
vacuum box Fit an inner white tip into each yellow tip
11133 For each sample assemble a TEVAreg and a DGA cartridge and
lock these onto the inner white tip (DGA cartridge below
TEVAreg
)
11134 Place reservoirs on the top end of the TEVAreg cartridge
11135 Seal unused openings on the vacuum box by inserting yellow
caps included with the vacuum box into unused white tips to
achieve a good seal during the separation Alternately plastic
tape can be used to seal the unused lid holes
11136 Turn the vacuum on and ensure proper fitting of the lid
11137 Add 5 mL of 3 M HNO3 to the column reservoir to precondition
the TEVAreg cartridges
11138 Adjust the vacuum to achieve a flow-rate of ~1 mLmin
IMPORTANT Unless the method specifies otherwise use a flow rate of ~ 1 mLmin
for load and strip solutions and ~ 2 -3 mLmin for rinse solutions
1114 TEVAreg
and DGA Resin Separation
11141 Transfer each solution from Step 11125 into the appropriate
reservoir Allow solution to pass through the stacked TEVAreg +
DGA cartridge at a flow rate of ~1 mLmin
11142 Add 5 mL of 6 M HNO3 to each tubebeaker as a rinse and
transfer each solution into the appropriate reservoir (the flow rate
can be adjusted to ~2 mLmin)
11143 Add a 5 mL rinse of 6 M HNO3 to each column (the flow rate
can be adjusted to ~2 mLmin)
11144 Turn off vacuum discard rinse solutions and remove reservoirs
and TEVAreg cartridges and discard Place new reservoirs on the
DGA cartridges
11145 Add a 20 mL rinse of 01 M HNO3 to each reservoir (flow rate
~1-2 mLmin)
NOTE The rinses with dilute nitric acid remove uranium while curium
and americium are retained Precipitation of uranium during
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 12 Revision 0
microprecipitation is inhibited by adding hydrogen peroxide to ensure
uranium is present as UO22+
11146 Add 15 mL of 3 M HNO3ndash025 M HF to each reservoir at ~1-2
mLmin to complex and remove Th from the DGA Resin
11147 Add 3 mL of 4 M HCl to each reservoir at ~1ndash2 mLmin to rinse
column of residual fluoride Once the HCl has passed through the
column quickly pulse the vacuum two or three times to
minimize the amount of residual HCl in the column prior to
proceeding
11148 Ensure that clean labeled plastic tubes are placed in the tube
rack under each cartridge For maximum removal of
interferences during elution also change connector tips prior to
CmAm elution
11149 Add 10 mL of 025 M HCl solution to elute curium and
americium from each cartridge reducing the flow rate to ~1
mLmin (or slightly slower)
111410 Set the curium fraction in the plastic tube aside for cerium
fluoride coprecipitation Step 112
111411 Discard the DGA cartridge
112 Preparation of the Sample Test Source
NOTE Instructions below describe preparation of a single sample test source (STS) Several
STSs can be prepared simultaneously if a multi-channel vacuum manifold system is available
1121 Pipet 100 microL of the cerium carrier solution into each tube
1122 Pipet 05 mL 30 wt H2O2 into each tube to prevent residual uranium from
precipitating
1123 Pipet 1 mL of concentrated HF into each tube
1124 Cap the tube and mix Allow samples sit for ~ 15 minutes before filtering
1125 Set up a filter apparatus to accommodate a 01-micron 25-mm membrane
filter on a microprecipitation filtering apparatus
Caution Following deposition of the microprecipitate there is no visible difference
between the two sides of the filter
1126 If a hydrophobic filter is used add a few drops of 95 ethanol to wet each
filter and apply vacuum Ensure that there are no leaks along the sides
before proceeding
1127 While vacuum is applied add 2-3 mL of filtered Type I water to each filter
and allow the liquid to drain
1128 Add the sample to the reservoir rinsing the sample tubes with ~3 mL of
water and transfer this rinse to filter apparatus Allow to drain
1129 Wash each filter with ~2-3 mL of water and allow to drain
11210 Wash each filter with ~1-2 mL of 95 ethanol to displace water
11211 Allow to drain completely before turning the vacuum off
11212 Mount the filter on a labeled adhesive mounting disk (or equivalent)
ensuring that the filter is not wrinkled and is centered on the mounting disk
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 13 Revision 0
11213 Place the filter under a heat lamp for approximately 5 minutes or longer
until it is completely dry
11214 Count filters for an appropriate period of time by alpha spectrometry
11215 Discard the filtrate to waste for future disposal If the filtrate is to be
retained it should be stored in a plastic container since glass will be
attacked by HF
NOTE Other methods for STS preparation such as electrodeposition or
microprecipitation with neodymium fluoride may be used in lieu of the cerium
fluoride microprecipitation but any such substitution must be validated as described
in Step 15
12 Data Analysis and Calculations
121 Equations for activity concentration combined standard uncertainty and
radiochemical yield (if required)
1211 The activity concentration of the analyte and its combined standard
uncertainty are calculated using the following equations
aata
ttata
IDRV
IDRAAC
2
t
t
2
2
a
a
2
2
t
t
22
a2
a
2
a
2
t
2
a
2
t
2
t
2
ta
2
ac
)()()()()(
R
Ru
V
Vu
A
AuAC
IDRV
IDARuACu
ttt
tD
e
aat
aD
e
Where
ACa = activity concentration of the analyte at time of collection (or other
specified reference time) in picocuries per liter (pCiL)
At = activity of the tracer added to the sample aliquant on the tracer
solution reference datetime (pCi)
Ra = net count rate of the analyte in the defined region of interest (ROI)
in counts per second (see 1212)
Rt = net count rate of the tracer in the defined ROI in counts per second
(see 1212)
Va = volume of the sample aliquant (L)
Dt = correction factor for decay of the tracer from its reference date and
time to the midpoint of the counting period
Da = correction factor for decay of the analyte from the time of sample
collection (or other reference time) to the midpoint of the counting
period
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 14 Revision 0
It = probability of α emission in the defined ROI per decay of the tracer
(Table 171)
Ia = probability of α emission in the defined ROI per decay of the analyte
(Table 171)
uc(ACa) = combined standard uncertainty of the activity concentration of the
analyte (pCiL)
u(At) = standard uncertainty of the activity of the tracer added to the sample
(pCi)
u(Ra) = standard uncertainty of the net count rate of the analyte (sminus1
) (see
1212)
u(Rt) = standard uncertainty of the net count rate of the tracer (sminus1
) (see
1212)
u(Va) = standard uncertainty of the size of the sample aliquant volume (L)
λt = decay constant for the tracer radionuclide (sminus1
see Table 171)
λa = decay constant for the analyte radionuclide (sminus1
see Table 171)
tt = time elapsed between the activity reference date for the tracer and
the midpoint of the sample count (s)
ta = time elapsed between the activity reference date for the sample (eg
collection date) and the midpoint of the sample count (s)
NOTE The uncertainties of the decay-correction factors and of the probability of decay
factors are assumed to be negligible
NOTE The equation for the combined standard uncertainty (uc(ACa)) calculation is arranged to
eliminate the possibility of dividing by zero if Ra = 0
NOTE The standard uncertainty of the activity of the tracer added to the sample must reflect the
uncertainty associated with the activity of the standard reference material and any other
significant sources of uncertainty such as those introduced during the preparation of the tracer
solution (eg weighing or dilution factors) and during the process of adding the tracer to the
sample
1212 The net count rate of an analyte or tracer and its standard uncertainty are
calculated using the following equations
b
bx
s
xx
t
C
t
CR
and
2
b
bx
2
s
xx
11)(
t
C
t
CRu
where
Rx = net count rate of analyte or tracer in counts per second
Cx = sample counts in the analyte or the tracer ROI
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 15 Revision 0
ts = sample count time (s)
Cbx = background counts in the same ROI as for x
tb = background count time (s)
u(Rx) = standard uncertainty of the net count rate of tracer or analyte in
counts per second2
If the radiochemical yield of the tracer is requested the yield and its combined
standard uncertainty can be calculated using the following equations
ttt
t
0370 IDA
RRY
and
2
2
2
t
t
2
2
t
t
2)()()(
)(
u
A
Au
R
RuRYRYuc
where
RY = radiochemical yield of the tracer expressed as a fraction
Rt = net count rate of the tracer in counts per second
At = activity of the tracer added to the sample (pCi)
Dt = correction factor for decay of the tracer from its reference date and
time to the midpoint of the counting period
It = probability of α emission in the defined ROI per decay of the tracer
(Table 171)
ε = detector efficiency expressed as a fraction
uc(RY) = combined standard uncertainty of the radiochemical yield
u(Rt) = standard uncertainty of the net count rate of the tracer in counts per
second
u(At) = standard uncertainty of the activity of the tracer added to the sample
(pCi)
u(ε) = standard uncertainty of the detector efficiency
1213 If the critical level concentration (Lc) or the minimum detectable
concentration (MDC) are requested (at an error rate of 5) they can be
calculated using the following equations 3
2 For methods with very low counts MARLAP Section 19522 recommends adding one count each to the gross
counts and the background counts when estimating the uncertainty of the respective net counts This minimizes
negative bias in the estimate of uncertainty and protects against calculating zero uncertainty when a total of zero
counts are observed for the sample and background 3 The formulations for the critical level and minimum detectable concentration are based on the Stapleton
Approximation as recommended in MARLAP Section 20A22 Equations 2054 and 20A32 and Equation 2074
respectively (EPA 2004) The formulations presented here assume an error rate of α = 005 β = 005 (with z1minusα =
z1minusβ = 1645) and d = 04 For methods with very low numbers of counts these expressions provide better estimates
than do the traditional formulas for the critical level and MDC
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 16 Revision 0
aatas
ttt
b
s
b
sbba
b
s
b
s
cIDRVt
IDAt
t
t
ttR
t
t
t
t
L
140645116770140
aatas
ttt
b
ssba
b
s 13291271
MDCIDRVt
IDAt
ttR
t
t
where
Rba = background count rate for the analyte in the defined ROI in counts
per second
122 Results Reporting
1221 The following data should be reported for each result volume of sample
used yield of tracer and its uncertainty and FWHM of each peak used in
the analysis
1222 The following conventions should be used for each result
12221 Result in scientific notation plusmn combined standard uncertainty
13 Method Performance
131 Method validation results performed prior to analyzing samples are to be documented
and reported as required
132 Expected processing time per batch of 10-20 samples plus QC
1321 For an analysis of a 02 L sample aliquant precipitation and preparation of
load solution takes ~1 h
1322 Purification and separation using cartridges and vacuum box system should
take ~2 h
1323 The sample test source preparation step takes ~075 h
1324 A four-hour counting time should be sufficient to meet the MQOs listed in
Step 14 assuming detector efficiency of 015ndash03 and radiochemical yield
of at least 05 A different counting time may be necessary to meet these
MQOs if any of the relevant parameters are significantly different
1325 Data should be ready for reduction ~8-9 h after beginning of analysis
14 Pollution Prevention The method utilizes small volume (2 mL) extraction chromatographic
resin columns This approach leads to a significant reduction in the volumes of load rinse
and strip solutions as compared to classical methods using ion exchange resins to separate
and purify the curium fraction
15 Waste Management
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 17 Revision 0
151 Types of waste generated per sample analyzed
1511 Approximately 210 mL basic waste from the initial sample
preconcentration
1512 Approximately 65 mL of acidic waste from loading and rinsing the two
extraction columns will be generated
1513 Approximately 25 mL of acidic waste from the microprecipitation method
for source preparation will be generated The waste contains 1 mL of HF
and ~ 5 mL of ethanol
1514 TEVAreg
cartridge ndash ready for appropriate disposal
1515 DGA cartridge ndash ready for appropriate disposal
1516 These waste streams may contain low levels of 243
Am (added as tracer) 244
Cm (added to LCS) and other radionuclides as present in samples
152 Evaluate all waste streams according to disposal requirements by applicable
regulations
16 References
Cited References
161 EPA 2009 Method Validation Guide for Radiological Laboratories Participating in
Incident Response Activities Revision 0 Office of Air and Radiation Washington
104 Perform Continuing Instrument Quality Control Testing according to ASTM Standard
Practice D7282 Sections 20 21 and 24 ldquoContinuing Instrument Quality Control
Testingrdquo and ldquoQuality Control for Alpha Spectrometry Systemsrdquo (Reference 163)
11 Procedure
111 Rapid Curium Separation using TEVAreg and DGA Resins
NOTE This method addresses the analysis of soluble curium only Solid material if present must be
removed from the sample prior to aliquanting by filtering the unpreserved sample aliquant through a
045-μm filter The solid material may be screened for radioactivity or saved for potential future analysis
1111 Aliquanting and Preparation
11111 Aliquant 200 mL of sample into a 225-mL centrifuge tube
1 This helps minimize interference from alpha-emitting isotopes with potentially overlapping energies
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 10 Revision 0
11112 Aliquant a second 200 mL portion of one sample into a 225-mL
centrifuge tube as a sample duplicate
11113 Add 200 mL reagent water to an empty 225-mL centrifuge tube
as a reagent blank
11114 Add 200 mL reagent water to an empty 225-mL centrifuge tube
for the LCS
11115 Acidify each sample with concentrated HNO3 to a pH of less
than 20 by adding HNO3 This usually requires about 05 mL of
HNO3
11116 Add 10-40 dpm 244
Cm standard solution to the LCS centrifuge
tube following laboratory protocol
11117 Add 10-40 dpm 243
Am tracer to the blank LCS and sample and
sample duplicates following laboratory protocol
11118 Add 1 mL of 15 M Ca(NO3)2 3 mL of 32 M (NH4)2HPO4
solution and 2ndash3 drops of phenolphthalein indicator to each
centrifuge tube
11119 Slowly add concentrated NH4OH to each centrifuge tube with a
squeeze bottle Add enough NH4OH to reach a dark pink
phenolphthalein end point and form Ca3(PO4)2 precipitate Cap
and mix tubes and centrifuge at 2000 revolutions per minute
(rpm) or more for ~5 minutes
Note If a sample aliquant larger than 200 mL is needed the aliquant may be added to
a large beaker heated on a hot plate to near boiling with reagents added and allowed
to cool and settle After pouring off enough of the supernate the precipitate may be
transferred to a 225 mL tube rinsing the beaker well with water and centrifuged
111110 Decant supernatant solution and discard to waste
1112 Preparation of the Load Solution
11121 Dissolve the calcium phosphate precipitate with 15 mL of 3 M
HNO3 - 10 M Al(NO3)3 If the residue volume is large or if
residual solids remain an additional 5 mL may be needed to
obtain complete dissolution
11122 Add 05 mL of 15 M sulfamic acid to each sample Swirl to mix
NOTE If elevated levels of 237
Np are potentially present in the sample also add 05 mL
of 4 mgmL iron carrier to enhance neptunium (Np) reduction to Np4+
The addition of
ascorbic acid in the next step will convert Fe3+
to Fe2+
and ensure removal of Np on
TEVAreg Resin
11123 Add 125 mL of 15 M ascorbic acid to each sample Swirl to
mix Wait 3 minutes
NOTE Plutonium (Pu) if present will be adjusted to Pu4+
to ensure retention and
removal on TEVAreg Resin A small amount of brown fumes results from nitrite
reaction with sulfamic acid The solution should clear with swirling If the solution
does not clear (is still dark) an additional small volume of sodium nitrite may be
added to clear the solution
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 11 Revision 0
11124 Add 1 mL of 35 M NaNO2 to each sample Swirl to mix
NOTE The load solution nitrate concentration is increased after valence adjustment to
provide greater retention of Am and more effective elution of calcium ions on DGA
Resin
11125 Add 15 mL concentrated HNO3 to each sample and swirl to mix
NOTE The steps in this section were optimized for a commercially available filtration
system Other vacuum systems may be substituted here The cartridges may be set up
and conditioned with nitric acid so that they are ready for column loading just prior
to completion of the valence adjustment steps More than one vacuum box may be
used to increase throughput
1113 Set up TEVAreg and DGA cartridges on the vacuum box system
11131 Place the inner centrifuge tube rack (supplied with vacuum box)
into the vacuum box with the centrifuge tubes in the rack Place
the lid on the vacuum box system
11132 Place the yellow outer tips into all 24 openings of the lid of the
vacuum box Fit an inner white tip into each yellow tip
11133 For each sample assemble a TEVAreg and a DGA cartridge and
lock these onto the inner white tip (DGA cartridge below
TEVAreg
)
11134 Place reservoirs on the top end of the TEVAreg cartridge
11135 Seal unused openings on the vacuum box by inserting yellow
caps included with the vacuum box into unused white tips to
achieve a good seal during the separation Alternately plastic
tape can be used to seal the unused lid holes
11136 Turn the vacuum on and ensure proper fitting of the lid
11137 Add 5 mL of 3 M HNO3 to the column reservoir to precondition
the TEVAreg cartridges
11138 Adjust the vacuum to achieve a flow-rate of ~1 mLmin
IMPORTANT Unless the method specifies otherwise use a flow rate of ~ 1 mLmin
for load and strip solutions and ~ 2 -3 mLmin for rinse solutions
1114 TEVAreg
and DGA Resin Separation
11141 Transfer each solution from Step 11125 into the appropriate
reservoir Allow solution to pass through the stacked TEVAreg +
DGA cartridge at a flow rate of ~1 mLmin
11142 Add 5 mL of 6 M HNO3 to each tubebeaker as a rinse and
transfer each solution into the appropriate reservoir (the flow rate
can be adjusted to ~2 mLmin)
11143 Add a 5 mL rinse of 6 M HNO3 to each column (the flow rate
can be adjusted to ~2 mLmin)
11144 Turn off vacuum discard rinse solutions and remove reservoirs
and TEVAreg cartridges and discard Place new reservoirs on the
DGA cartridges
11145 Add a 20 mL rinse of 01 M HNO3 to each reservoir (flow rate
~1-2 mLmin)
NOTE The rinses with dilute nitric acid remove uranium while curium
and americium are retained Precipitation of uranium during
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 12 Revision 0
microprecipitation is inhibited by adding hydrogen peroxide to ensure
uranium is present as UO22+
11146 Add 15 mL of 3 M HNO3ndash025 M HF to each reservoir at ~1-2
mLmin to complex and remove Th from the DGA Resin
11147 Add 3 mL of 4 M HCl to each reservoir at ~1ndash2 mLmin to rinse
column of residual fluoride Once the HCl has passed through the
column quickly pulse the vacuum two or three times to
minimize the amount of residual HCl in the column prior to
proceeding
11148 Ensure that clean labeled plastic tubes are placed in the tube
rack under each cartridge For maximum removal of
interferences during elution also change connector tips prior to
CmAm elution
11149 Add 10 mL of 025 M HCl solution to elute curium and
americium from each cartridge reducing the flow rate to ~1
mLmin (or slightly slower)
111410 Set the curium fraction in the plastic tube aside for cerium
fluoride coprecipitation Step 112
111411 Discard the DGA cartridge
112 Preparation of the Sample Test Source
NOTE Instructions below describe preparation of a single sample test source (STS) Several
STSs can be prepared simultaneously if a multi-channel vacuum manifold system is available
1121 Pipet 100 microL of the cerium carrier solution into each tube
1122 Pipet 05 mL 30 wt H2O2 into each tube to prevent residual uranium from
precipitating
1123 Pipet 1 mL of concentrated HF into each tube
1124 Cap the tube and mix Allow samples sit for ~ 15 minutes before filtering
1125 Set up a filter apparatus to accommodate a 01-micron 25-mm membrane
filter on a microprecipitation filtering apparatus
Caution Following deposition of the microprecipitate there is no visible difference
between the two sides of the filter
1126 If a hydrophobic filter is used add a few drops of 95 ethanol to wet each
filter and apply vacuum Ensure that there are no leaks along the sides
before proceeding
1127 While vacuum is applied add 2-3 mL of filtered Type I water to each filter
and allow the liquid to drain
1128 Add the sample to the reservoir rinsing the sample tubes with ~3 mL of
water and transfer this rinse to filter apparatus Allow to drain
1129 Wash each filter with ~2-3 mL of water and allow to drain
11210 Wash each filter with ~1-2 mL of 95 ethanol to displace water
11211 Allow to drain completely before turning the vacuum off
11212 Mount the filter on a labeled adhesive mounting disk (or equivalent)
ensuring that the filter is not wrinkled and is centered on the mounting disk
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 13 Revision 0
11213 Place the filter under a heat lamp for approximately 5 minutes or longer
until it is completely dry
11214 Count filters for an appropriate period of time by alpha spectrometry
11215 Discard the filtrate to waste for future disposal If the filtrate is to be
retained it should be stored in a plastic container since glass will be
attacked by HF
NOTE Other methods for STS preparation such as electrodeposition or
microprecipitation with neodymium fluoride may be used in lieu of the cerium
fluoride microprecipitation but any such substitution must be validated as described
in Step 15
12 Data Analysis and Calculations
121 Equations for activity concentration combined standard uncertainty and
radiochemical yield (if required)
1211 The activity concentration of the analyte and its combined standard
uncertainty are calculated using the following equations
aata
ttata
IDRV
IDRAAC
2
t
t
2
2
a
a
2
2
t
t
22
a2
a
2
a
2
t
2
a
2
t
2
t
2
ta
2
ac
)()()()()(
R
Ru
V
Vu
A
AuAC
IDRV
IDARuACu
ttt
tD
e
aat
aD
e
Where
ACa = activity concentration of the analyte at time of collection (or other
specified reference time) in picocuries per liter (pCiL)
At = activity of the tracer added to the sample aliquant on the tracer
solution reference datetime (pCi)
Ra = net count rate of the analyte in the defined region of interest (ROI)
in counts per second (see 1212)
Rt = net count rate of the tracer in the defined ROI in counts per second
(see 1212)
Va = volume of the sample aliquant (L)
Dt = correction factor for decay of the tracer from its reference date and
time to the midpoint of the counting period
Da = correction factor for decay of the analyte from the time of sample
collection (or other reference time) to the midpoint of the counting
period
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 14 Revision 0
It = probability of α emission in the defined ROI per decay of the tracer
(Table 171)
Ia = probability of α emission in the defined ROI per decay of the analyte
(Table 171)
uc(ACa) = combined standard uncertainty of the activity concentration of the
analyte (pCiL)
u(At) = standard uncertainty of the activity of the tracer added to the sample
(pCi)
u(Ra) = standard uncertainty of the net count rate of the analyte (sminus1
) (see
1212)
u(Rt) = standard uncertainty of the net count rate of the tracer (sminus1
) (see
1212)
u(Va) = standard uncertainty of the size of the sample aliquant volume (L)
λt = decay constant for the tracer radionuclide (sminus1
see Table 171)
λa = decay constant for the analyte radionuclide (sminus1
see Table 171)
tt = time elapsed between the activity reference date for the tracer and
the midpoint of the sample count (s)
ta = time elapsed between the activity reference date for the sample (eg
collection date) and the midpoint of the sample count (s)
NOTE The uncertainties of the decay-correction factors and of the probability of decay
factors are assumed to be negligible
NOTE The equation for the combined standard uncertainty (uc(ACa)) calculation is arranged to
eliminate the possibility of dividing by zero if Ra = 0
NOTE The standard uncertainty of the activity of the tracer added to the sample must reflect the
uncertainty associated with the activity of the standard reference material and any other
significant sources of uncertainty such as those introduced during the preparation of the tracer
solution (eg weighing or dilution factors) and during the process of adding the tracer to the
sample
1212 The net count rate of an analyte or tracer and its standard uncertainty are
calculated using the following equations
b
bx
s
xx
t
C
t
CR
and
2
b
bx
2
s
xx
11)(
t
C
t
CRu
where
Rx = net count rate of analyte or tracer in counts per second
Cx = sample counts in the analyte or the tracer ROI
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 15 Revision 0
ts = sample count time (s)
Cbx = background counts in the same ROI as for x
tb = background count time (s)
u(Rx) = standard uncertainty of the net count rate of tracer or analyte in
counts per second2
If the radiochemical yield of the tracer is requested the yield and its combined
standard uncertainty can be calculated using the following equations
ttt
t
0370 IDA
RRY
and
2
2
2
t
t
2
2
t
t
2)()()(
)(
u
A
Au
R
RuRYRYuc
where
RY = radiochemical yield of the tracer expressed as a fraction
Rt = net count rate of the tracer in counts per second
At = activity of the tracer added to the sample (pCi)
Dt = correction factor for decay of the tracer from its reference date and
time to the midpoint of the counting period
It = probability of α emission in the defined ROI per decay of the tracer
(Table 171)
ε = detector efficiency expressed as a fraction
uc(RY) = combined standard uncertainty of the radiochemical yield
u(Rt) = standard uncertainty of the net count rate of the tracer in counts per
second
u(At) = standard uncertainty of the activity of the tracer added to the sample
(pCi)
u(ε) = standard uncertainty of the detector efficiency
1213 If the critical level concentration (Lc) or the minimum detectable
concentration (MDC) are requested (at an error rate of 5) they can be
calculated using the following equations 3
2 For methods with very low counts MARLAP Section 19522 recommends adding one count each to the gross
counts and the background counts when estimating the uncertainty of the respective net counts This minimizes
negative bias in the estimate of uncertainty and protects against calculating zero uncertainty when a total of zero
counts are observed for the sample and background 3 The formulations for the critical level and minimum detectable concentration are based on the Stapleton
Approximation as recommended in MARLAP Section 20A22 Equations 2054 and 20A32 and Equation 2074
respectively (EPA 2004) The formulations presented here assume an error rate of α = 005 β = 005 (with z1minusα =
z1minusβ = 1645) and d = 04 For methods with very low numbers of counts these expressions provide better estimates
than do the traditional formulas for the critical level and MDC
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 16 Revision 0
aatas
ttt
b
s
b
sbba
b
s
b
s
cIDRVt
IDAt
t
t
ttR
t
t
t
t
L
140645116770140
aatas
ttt
b
ssba
b
s 13291271
MDCIDRVt
IDAt
ttR
t
t
where
Rba = background count rate for the analyte in the defined ROI in counts
per second
122 Results Reporting
1221 The following data should be reported for each result volume of sample
used yield of tracer and its uncertainty and FWHM of each peak used in
the analysis
1222 The following conventions should be used for each result
12221 Result in scientific notation plusmn combined standard uncertainty
13 Method Performance
131 Method validation results performed prior to analyzing samples are to be documented
and reported as required
132 Expected processing time per batch of 10-20 samples plus QC
1321 For an analysis of a 02 L sample aliquant precipitation and preparation of
load solution takes ~1 h
1322 Purification and separation using cartridges and vacuum box system should
take ~2 h
1323 The sample test source preparation step takes ~075 h
1324 A four-hour counting time should be sufficient to meet the MQOs listed in
Step 14 assuming detector efficiency of 015ndash03 and radiochemical yield
of at least 05 A different counting time may be necessary to meet these
MQOs if any of the relevant parameters are significantly different
1325 Data should be ready for reduction ~8-9 h after beginning of analysis
14 Pollution Prevention The method utilizes small volume (2 mL) extraction chromatographic
resin columns This approach leads to a significant reduction in the volumes of load rinse
and strip solutions as compared to classical methods using ion exchange resins to separate
and purify the curium fraction
15 Waste Management
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 17 Revision 0
151 Types of waste generated per sample analyzed
1511 Approximately 210 mL basic waste from the initial sample
preconcentration
1512 Approximately 65 mL of acidic waste from loading and rinsing the two
extraction columns will be generated
1513 Approximately 25 mL of acidic waste from the microprecipitation method
for source preparation will be generated The waste contains 1 mL of HF
and ~ 5 mL of ethanol
1514 TEVAreg
cartridge ndash ready for appropriate disposal
1515 DGA cartridge ndash ready for appropriate disposal
1516 These waste streams may contain low levels of 243
Am (added as tracer) 244
Cm (added to LCS) and other radionuclides as present in samples
152 Evaluate all waste streams according to disposal requirements by applicable
regulations
16 References
Cited References
161 EPA 2009 Method Validation Guide for Radiological Laboratories Participating in
Incident Response Activities Revision 0 Office of Air and Radiation Washington
104 Perform Continuing Instrument Quality Control Testing according to ASTM Standard
Practice D7282 Sections 20 21 and 24 ldquoContinuing Instrument Quality Control
Testingrdquo and ldquoQuality Control for Alpha Spectrometry Systemsrdquo (Reference 163)
11 Procedure
111 Rapid Curium Separation using TEVAreg and DGA Resins
NOTE This method addresses the analysis of soluble curium only Solid material if present must be
removed from the sample prior to aliquanting by filtering the unpreserved sample aliquant through a
045-μm filter The solid material may be screened for radioactivity or saved for potential future analysis
1111 Aliquanting and Preparation
11111 Aliquant 200 mL of sample into a 225-mL centrifuge tube
1 This helps minimize interference from alpha-emitting isotopes with potentially overlapping energies
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 10 Revision 0
11112 Aliquant a second 200 mL portion of one sample into a 225-mL
centrifuge tube as a sample duplicate
11113 Add 200 mL reagent water to an empty 225-mL centrifuge tube
as a reagent blank
11114 Add 200 mL reagent water to an empty 225-mL centrifuge tube
for the LCS
11115 Acidify each sample with concentrated HNO3 to a pH of less
than 20 by adding HNO3 This usually requires about 05 mL of
HNO3
11116 Add 10-40 dpm 244
Cm standard solution to the LCS centrifuge
tube following laboratory protocol
11117 Add 10-40 dpm 243
Am tracer to the blank LCS and sample and
sample duplicates following laboratory protocol
11118 Add 1 mL of 15 M Ca(NO3)2 3 mL of 32 M (NH4)2HPO4
solution and 2ndash3 drops of phenolphthalein indicator to each
centrifuge tube
11119 Slowly add concentrated NH4OH to each centrifuge tube with a
squeeze bottle Add enough NH4OH to reach a dark pink
phenolphthalein end point and form Ca3(PO4)2 precipitate Cap
and mix tubes and centrifuge at 2000 revolutions per minute
(rpm) or more for ~5 minutes
Note If a sample aliquant larger than 200 mL is needed the aliquant may be added to
a large beaker heated on a hot plate to near boiling with reagents added and allowed
to cool and settle After pouring off enough of the supernate the precipitate may be
transferred to a 225 mL tube rinsing the beaker well with water and centrifuged
111110 Decant supernatant solution and discard to waste
1112 Preparation of the Load Solution
11121 Dissolve the calcium phosphate precipitate with 15 mL of 3 M
HNO3 - 10 M Al(NO3)3 If the residue volume is large or if
residual solids remain an additional 5 mL may be needed to
obtain complete dissolution
11122 Add 05 mL of 15 M sulfamic acid to each sample Swirl to mix
NOTE If elevated levels of 237
Np are potentially present in the sample also add 05 mL
of 4 mgmL iron carrier to enhance neptunium (Np) reduction to Np4+
The addition of
ascorbic acid in the next step will convert Fe3+
to Fe2+
and ensure removal of Np on
TEVAreg Resin
11123 Add 125 mL of 15 M ascorbic acid to each sample Swirl to
mix Wait 3 minutes
NOTE Plutonium (Pu) if present will be adjusted to Pu4+
to ensure retention and
removal on TEVAreg Resin A small amount of brown fumes results from nitrite
reaction with sulfamic acid The solution should clear with swirling If the solution
does not clear (is still dark) an additional small volume of sodium nitrite may be
added to clear the solution
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 11 Revision 0
11124 Add 1 mL of 35 M NaNO2 to each sample Swirl to mix
NOTE The load solution nitrate concentration is increased after valence adjustment to
provide greater retention of Am and more effective elution of calcium ions on DGA
Resin
11125 Add 15 mL concentrated HNO3 to each sample and swirl to mix
NOTE The steps in this section were optimized for a commercially available filtration
system Other vacuum systems may be substituted here The cartridges may be set up
and conditioned with nitric acid so that they are ready for column loading just prior
to completion of the valence adjustment steps More than one vacuum box may be
used to increase throughput
1113 Set up TEVAreg and DGA cartridges on the vacuum box system
11131 Place the inner centrifuge tube rack (supplied with vacuum box)
into the vacuum box with the centrifuge tubes in the rack Place
the lid on the vacuum box system
11132 Place the yellow outer tips into all 24 openings of the lid of the
vacuum box Fit an inner white tip into each yellow tip
11133 For each sample assemble a TEVAreg and a DGA cartridge and
lock these onto the inner white tip (DGA cartridge below
TEVAreg
)
11134 Place reservoirs on the top end of the TEVAreg cartridge
11135 Seal unused openings on the vacuum box by inserting yellow
caps included with the vacuum box into unused white tips to
achieve a good seal during the separation Alternately plastic
tape can be used to seal the unused lid holes
11136 Turn the vacuum on and ensure proper fitting of the lid
11137 Add 5 mL of 3 M HNO3 to the column reservoir to precondition
the TEVAreg cartridges
11138 Adjust the vacuum to achieve a flow-rate of ~1 mLmin
IMPORTANT Unless the method specifies otherwise use a flow rate of ~ 1 mLmin
for load and strip solutions and ~ 2 -3 mLmin for rinse solutions
1114 TEVAreg
and DGA Resin Separation
11141 Transfer each solution from Step 11125 into the appropriate
reservoir Allow solution to pass through the stacked TEVAreg +
DGA cartridge at a flow rate of ~1 mLmin
11142 Add 5 mL of 6 M HNO3 to each tubebeaker as a rinse and
transfer each solution into the appropriate reservoir (the flow rate
can be adjusted to ~2 mLmin)
11143 Add a 5 mL rinse of 6 M HNO3 to each column (the flow rate
can be adjusted to ~2 mLmin)
11144 Turn off vacuum discard rinse solutions and remove reservoirs
and TEVAreg cartridges and discard Place new reservoirs on the
DGA cartridges
11145 Add a 20 mL rinse of 01 M HNO3 to each reservoir (flow rate
~1-2 mLmin)
NOTE The rinses with dilute nitric acid remove uranium while curium
and americium are retained Precipitation of uranium during
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 12 Revision 0
microprecipitation is inhibited by adding hydrogen peroxide to ensure
uranium is present as UO22+
11146 Add 15 mL of 3 M HNO3ndash025 M HF to each reservoir at ~1-2
mLmin to complex and remove Th from the DGA Resin
11147 Add 3 mL of 4 M HCl to each reservoir at ~1ndash2 mLmin to rinse
column of residual fluoride Once the HCl has passed through the
column quickly pulse the vacuum two or three times to
minimize the amount of residual HCl in the column prior to
proceeding
11148 Ensure that clean labeled plastic tubes are placed in the tube
rack under each cartridge For maximum removal of
interferences during elution also change connector tips prior to
CmAm elution
11149 Add 10 mL of 025 M HCl solution to elute curium and
americium from each cartridge reducing the flow rate to ~1
mLmin (or slightly slower)
111410 Set the curium fraction in the plastic tube aside for cerium
fluoride coprecipitation Step 112
111411 Discard the DGA cartridge
112 Preparation of the Sample Test Source
NOTE Instructions below describe preparation of a single sample test source (STS) Several
STSs can be prepared simultaneously if a multi-channel vacuum manifold system is available
1121 Pipet 100 microL of the cerium carrier solution into each tube
1122 Pipet 05 mL 30 wt H2O2 into each tube to prevent residual uranium from
precipitating
1123 Pipet 1 mL of concentrated HF into each tube
1124 Cap the tube and mix Allow samples sit for ~ 15 minutes before filtering
1125 Set up a filter apparatus to accommodate a 01-micron 25-mm membrane
filter on a microprecipitation filtering apparatus
Caution Following deposition of the microprecipitate there is no visible difference
between the two sides of the filter
1126 If a hydrophobic filter is used add a few drops of 95 ethanol to wet each
filter and apply vacuum Ensure that there are no leaks along the sides
before proceeding
1127 While vacuum is applied add 2-3 mL of filtered Type I water to each filter
and allow the liquid to drain
1128 Add the sample to the reservoir rinsing the sample tubes with ~3 mL of
water and transfer this rinse to filter apparatus Allow to drain
1129 Wash each filter with ~2-3 mL of water and allow to drain
11210 Wash each filter with ~1-2 mL of 95 ethanol to displace water
11211 Allow to drain completely before turning the vacuum off
11212 Mount the filter on a labeled adhesive mounting disk (or equivalent)
ensuring that the filter is not wrinkled and is centered on the mounting disk
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 13 Revision 0
11213 Place the filter under a heat lamp for approximately 5 minutes or longer
until it is completely dry
11214 Count filters for an appropriate period of time by alpha spectrometry
11215 Discard the filtrate to waste for future disposal If the filtrate is to be
retained it should be stored in a plastic container since glass will be
attacked by HF
NOTE Other methods for STS preparation such as electrodeposition or
microprecipitation with neodymium fluoride may be used in lieu of the cerium
fluoride microprecipitation but any such substitution must be validated as described
in Step 15
12 Data Analysis and Calculations
121 Equations for activity concentration combined standard uncertainty and
radiochemical yield (if required)
1211 The activity concentration of the analyte and its combined standard
uncertainty are calculated using the following equations
aata
ttata
IDRV
IDRAAC
2
t
t
2
2
a
a
2
2
t
t
22
a2
a
2
a
2
t
2
a
2
t
2
t
2
ta
2
ac
)()()()()(
R
Ru
V
Vu
A
AuAC
IDRV
IDARuACu
ttt
tD
e
aat
aD
e
Where
ACa = activity concentration of the analyte at time of collection (or other
specified reference time) in picocuries per liter (pCiL)
At = activity of the tracer added to the sample aliquant on the tracer
solution reference datetime (pCi)
Ra = net count rate of the analyte in the defined region of interest (ROI)
in counts per second (see 1212)
Rt = net count rate of the tracer in the defined ROI in counts per second
(see 1212)
Va = volume of the sample aliquant (L)
Dt = correction factor for decay of the tracer from its reference date and
time to the midpoint of the counting period
Da = correction factor for decay of the analyte from the time of sample
collection (or other reference time) to the midpoint of the counting
period
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 14 Revision 0
It = probability of α emission in the defined ROI per decay of the tracer
(Table 171)
Ia = probability of α emission in the defined ROI per decay of the analyte
(Table 171)
uc(ACa) = combined standard uncertainty of the activity concentration of the
analyte (pCiL)
u(At) = standard uncertainty of the activity of the tracer added to the sample
(pCi)
u(Ra) = standard uncertainty of the net count rate of the analyte (sminus1
) (see
1212)
u(Rt) = standard uncertainty of the net count rate of the tracer (sminus1
) (see
1212)
u(Va) = standard uncertainty of the size of the sample aliquant volume (L)
λt = decay constant for the tracer radionuclide (sminus1
see Table 171)
λa = decay constant for the analyte radionuclide (sminus1
see Table 171)
tt = time elapsed between the activity reference date for the tracer and
the midpoint of the sample count (s)
ta = time elapsed between the activity reference date for the sample (eg
collection date) and the midpoint of the sample count (s)
NOTE The uncertainties of the decay-correction factors and of the probability of decay
factors are assumed to be negligible
NOTE The equation for the combined standard uncertainty (uc(ACa)) calculation is arranged to
eliminate the possibility of dividing by zero if Ra = 0
NOTE The standard uncertainty of the activity of the tracer added to the sample must reflect the
uncertainty associated with the activity of the standard reference material and any other
significant sources of uncertainty such as those introduced during the preparation of the tracer
solution (eg weighing or dilution factors) and during the process of adding the tracer to the
sample
1212 The net count rate of an analyte or tracer and its standard uncertainty are
calculated using the following equations
b
bx
s
xx
t
C
t
CR
and
2
b
bx
2
s
xx
11)(
t
C
t
CRu
where
Rx = net count rate of analyte or tracer in counts per second
Cx = sample counts in the analyte or the tracer ROI
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 15 Revision 0
ts = sample count time (s)
Cbx = background counts in the same ROI as for x
tb = background count time (s)
u(Rx) = standard uncertainty of the net count rate of tracer or analyte in
counts per second2
If the radiochemical yield of the tracer is requested the yield and its combined
standard uncertainty can be calculated using the following equations
ttt
t
0370 IDA
RRY
and
2
2
2
t
t
2
2
t
t
2)()()(
)(
u
A
Au
R
RuRYRYuc
where
RY = radiochemical yield of the tracer expressed as a fraction
Rt = net count rate of the tracer in counts per second
At = activity of the tracer added to the sample (pCi)
Dt = correction factor for decay of the tracer from its reference date and
time to the midpoint of the counting period
It = probability of α emission in the defined ROI per decay of the tracer
(Table 171)
ε = detector efficiency expressed as a fraction
uc(RY) = combined standard uncertainty of the radiochemical yield
u(Rt) = standard uncertainty of the net count rate of the tracer in counts per
second
u(At) = standard uncertainty of the activity of the tracer added to the sample
(pCi)
u(ε) = standard uncertainty of the detector efficiency
1213 If the critical level concentration (Lc) or the minimum detectable
concentration (MDC) are requested (at an error rate of 5) they can be
calculated using the following equations 3
2 For methods with very low counts MARLAP Section 19522 recommends adding one count each to the gross
counts and the background counts when estimating the uncertainty of the respective net counts This minimizes
negative bias in the estimate of uncertainty and protects against calculating zero uncertainty when a total of zero
counts are observed for the sample and background 3 The formulations for the critical level and minimum detectable concentration are based on the Stapleton
Approximation as recommended in MARLAP Section 20A22 Equations 2054 and 20A32 and Equation 2074
respectively (EPA 2004) The formulations presented here assume an error rate of α = 005 β = 005 (with z1minusα =
z1minusβ = 1645) and d = 04 For methods with very low numbers of counts these expressions provide better estimates
than do the traditional formulas for the critical level and MDC
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 16 Revision 0
aatas
ttt
b
s
b
sbba
b
s
b
s
cIDRVt
IDAt
t
t
ttR
t
t
t
t
L
140645116770140
aatas
ttt
b
ssba
b
s 13291271
MDCIDRVt
IDAt
ttR
t
t
where
Rba = background count rate for the analyte in the defined ROI in counts
per second
122 Results Reporting
1221 The following data should be reported for each result volume of sample
used yield of tracer and its uncertainty and FWHM of each peak used in
the analysis
1222 The following conventions should be used for each result
12221 Result in scientific notation plusmn combined standard uncertainty
13 Method Performance
131 Method validation results performed prior to analyzing samples are to be documented
and reported as required
132 Expected processing time per batch of 10-20 samples plus QC
1321 For an analysis of a 02 L sample aliquant precipitation and preparation of
load solution takes ~1 h
1322 Purification and separation using cartridges and vacuum box system should
take ~2 h
1323 The sample test source preparation step takes ~075 h
1324 A four-hour counting time should be sufficient to meet the MQOs listed in
Step 14 assuming detector efficiency of 015ndash03 and radiochemical yield
of at least 05 A different counting time may be necessary to meet these
MQOs if any of the relevant parameters are significantly different
1325 Data should be ready for reduction ~8-9 h after beginning of analysis
14 Pollution Prevention The method utilizes small volume (2 mL) extraction chromatographic
resin columns This approach leads to a significant reduction in the volumes of load rinse
and strip solutions as compared to classical methods using ion exchange resins to separate
and purify the curium fraction
15 Waste Management
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 17 Revision 0
151 Types of waste generated per sample analyzed
1511 Approximately 210 mL basic waste from the initial sample
preconcentration
1512 Approximately 65 mL of acidic waste from loading and rinsing the two
extraction columns will be generated
1513 Approximately 25 mL of acidic waste from the microprecipitation method
for source preparation will be generated The waste contains 1 mL of HF
and ~ 5 mL of ethanol
1514 TEVAreg
cartridge ndash ready for appropriate disposal
1515 DGA cartridge ndash ready for appropriate disposal
1516 These waste streams may contain low levels of 243
Am (added as tracer) 244
Cm (added to LCS) and other radionuclides as present in samples
152 Evaluate all waste streams according to disposal requirements by applicable
regulations
16 References
Cited References
161 EPA 2009 Method Validation Guide for Radiological Laboratories Participating in
Incident Response Activities Revision 0 Office of Air and Radiation Washington
104 Perform Continuing Instrument Quality Control Testing according to ASTM Standard
Practice D7282 Sections 20 21 and 24 ldquoContinuing Instrument Quality Control
Testingrdquo and ldquoQuality Control for Alpha Spectrometry Systemsrdquo (Reference 163)
11 Procedure
111 Rapid Curium Separation using TEVAreg and DGA Resins
NOTE This method addresses the analysis of soluble curium only Solid material if present must be
removed from the sample prior to aliquanting by filtering the unpreserved sample aliquant through a
045-μm filter The solid material may be screened for radioactivity or saved for potential future analysis
1111 Aliquanting and Preparation
11111 Aliquant 200 mL of sample into a 225-mL centrifuge tube
1 This helps minimize interference from alpha-emitting isotopes with potentially overlapping energies
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 10 Revision 0
11112 Aliquant a second 200 mL portion of one sample into a 225-mL
centrifuge tube as a sample duplicate
11113 Add 200 mL reagent water to an empty 225-mL centrifuge tube
as a reagent blank
11114 Add 200 mL reagent water to an empty 225-mL centrifuge tube
for the LCS
11115 Acidify each sample with concentrated HNO3 to a pH of less
than 20 by adding HNO3 This usually requires about 05 mL of
HNO3
11116 Add 10-40 dpm 244
Cm standard solution to the LCS centrifuge
tube following laboratory protocol
11117 Add 10-40 dpm 243
Am tracer to the blank LCS and sample and
sample duplicates following laboratory protocol
11118 Add 1 mL of 15 M Ca(NO3)2 3 mL of 32 M (NH4)2HPO4
solution and 2ndash3 drops of phenolphthalein indicator to each
centrifuge tube
11119 Slowly add concentrated NH4OH to each centrifuge tube with a
squeeze bottle Add enough NH4OH to reach a dark pink
phenolphthalein end point and form Ca3(PO4)2 precipitate Cap
and mix tubes and centrifuge at 2000 revolutions per minute
(rpm) or more for ~5 minutes
Note If a sample aliquant larger than 200 mL is needed the aliquant may be added to
a large beaker heated on a hot plate to near boiling with reagents added and allowed
to cool and settle After pouring off enough of the supernate the precipitate may be
transferred to a 225 mL tube rinsing the beaker well with water and centrifuged
111110 Decant supernatant solution and discard to waste
1112 Preparation of the Load Solution
11121 Dissolve the calcium phosphate precipitate with 15 mL of 3 M
HNO3 - 10 M Al(NO3)3 If the residue volume is large or if
residual solids remain an additional 5 mL may be needed to
obtain complete dissolution
11122 Add 05 mL of 15 M sulfamic acid to each sample Swirl to mix
NOTE If elevated levels of 237
Np are potentially present in the sample also add 05 mL
of 4 mgmL iron carrier to enhance neptunium (Np) reduction to Np4+
The addition of
ascorbic acid in the next step will convert Fe3+
to Fe2+
and ensure removal of Np on
TEVAreg Resin
11123 Add 125 mL of 15 M ascorbic acid to each sample Swirl to
mix Wait 3 minutes
NOTE Plutonium (Pu) if present will be adjusted to Pu4+
to ensure retention and
removal on TEVAreg Resin A small amount of brown fumes results from nitrite
reaction with sulfamic acid The solution should clear with swirling If the solution
does not clear (is still dark) an additional small volume of sodium nitrite may be
added to clear the solution
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 11 Revision 0
11124 Add 1 mL of 35 M NaNO2 to each sample Swirl to mix
NOTE The load solution nitrate concentration is increased after valence adjustment to
provide greater retention of Am and more effective elution of calcium ions on DGA
Resin
11125 Add 15 mL concentrated HNO3 to each sample and swirl to mix
NOTE The steps in this section were optimized for a commercially available filtration
system Other vacuum systems may be substituted here The cartridges may be set up
and conditioned with nitric acid so that they are ready for column loading just prior
to completion of the valence adjustment steps More than one vacuum box may be
used to increase throughput
1113 Set up TEVAreg and DGA cartridges on the vacuum box system
11131 Place the inner centrifuge tube rack (supplied with vacuum box)
into the vacuum box with the centrifuge tubes in the rack Place
the lid on the vacuum box system
11132 Place the yellow outer tips into all 24 openings of the lid of the
vacuum box Fit an inner white tip into each yellow tip
11133 For each sample assemble a TEVAreg and a DGA cartridge and
lock these onto the inner white tip (DGA cartridge below
TEVAreg
)
11134 Place reservoirs on the top end of the TEVAreg cartridge
11135 Seal unused openings on the vacuum box by inserting yellow
caps included with the vacuum box into unused white tips to
achieve a good seal during the separation Alternately plastic
tape can be used to seal the unused lid holes
11136 Turn the vacuum on and ensure proper fitting of the lid
11137 Add 5 mL of 3 M HNO3 to the column reservoir to precondition
the TEVAreg cartridges
11138 Adjust the vacuum to achieve a flow-rate of ~1 mLmin
IMPORTANT Unless the method specifies otherwise use a flow rate of ~ 1 mLmin
for load and strip solutions and ~ 2 -3 mLmin for rinse solutions
1114 TEVAreg
and DGA Resin Separation
11141 Transfer each solution from Step 11125 into the appropriate
reservoir Allow solution to pass through the stacked TEVAreg +
DGA cartridge at a flow rate of ~1 mLmin
11142 Add 5 mL of 6 M HNO3 to each tubebeaker as a rinse and
transfer each solution into the appropriate reservoir (the flow rate
can be adjusted to ~2 mLmin)
11143 Add a 5 mL rinse of 6 M HNO3 to each column (the flow rate
can be adjusted to ~2 mLmin)
11144 Turn off vacuum discard rinse solutions and remove reservoirs
and TEVAreg cartridges and discard Place new reservoirs on the
DGA cartridges
11145 Add a 20 mL rinse of 01 M HNO3 to each reservoir (flow rate
~1-2 mLmin)
NOTE The rinses with dilute nitric acid remove uranium while curium
and americium are retained Precipitation of uranium during
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 12 Revision 0
microprecipitation is inhibited by adding hydrogen peroxide to ensure
uranium is present as UO22+
11146 Add 15 mL of 3 M HNO3ndash025 M HF to each reservoir at ~1-2
mLmin to complex and remove Th from the DGA Resin
11147 Add 3 mL of 4 M HCl to each reservoir at ~1ndash2 mLmin to rinse
column of residual fluoride Once the HCl has passed through the
column quickly pulse the vacuum two or three times to
minimize the amount of residual HCl in the column prior to
proceeding
11148 Ensure that clean labeled plastic tubes are placed in the tube
rack under each cartridge For maximum removal of
interferences during elution also change connector tips prior to
CmAm elution
11149 Add 10 mL of 025 M HCl solution to elute curium and
americium from each cartridge reducing the flow rate to ~1
mLmin (or slightly slower)
111410 Set the curium fraction in the plastic tube aside for cerium
fluoride coprecipitation Step 112
111411 Discard the DGA cartridge
112 Preparation of the Sample Test Source
NOTE Instructions below describe preparation of a single sample test source (STS) Several
STSs can be prepared simultaneously if a multi-channel vacuum manifold system is available
1121 Pipet 100 microL of the cerium carrier solution into each tube
1122 Pipet 05 mL 30 wt H2O2 into each tube to prevent residual uranium from
precipitating
1123 Pipet 1 mL of concentrated HF into each tube
1124 Cap the tube and mix Allow samples sit for ~ 15 minutes before filtering
1125 Set up a filter apparatus to accommodate a 01-micron 25-mm membrane
filter on a microprecipitation filtering apparatus
Caution Following deposition of the microprecipitate there is no visible difference
between the two sides of the filter
1126 If a hydrophobic filter is used add a few drops of 95 ethanol to wet each
filter and apply vacuum Ensure that there are no leaks along the sides
before proceeding
1127 While vacuum is applied add 2-3 mL of filtered Type I water to each filter
and allow the liquid to drain
1128 Add the sample to the reservoir rinsing the sample tubes with ~3 mL of
water and transfer this rinse to filter apparatus Allow to drain
1129 Wash each filter with ~2-3 mL of water and allow to drain
11210 Wash each filter with ~1-2 mL of 95 ethanol to displace water
11211 Allow to drain completely before turning the vacuum off
11212 Mount the filter on a labeled adhesive mounting disk (or equivalent)
ensuring that the filter is not wrinkled and is centered on the mounting disk
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 13 Revision 0
11213 Place the filter under a heat lamp for approximately 5 minutes or longer
until it is completely dry
11214 Count filters for an appropriate period of time by alpha spectrometry
11215 Discard the filtrate to waste for future disposal If the filtrate is to be
retained it should be stored in a plastic container since glass will be
attacked by HF
NOTE Other methods for STS preparation such as electrodeposition or
microprecipitation with neodymium fluoride may be used in lieu of the cerium
fluoride microprecipitation but any such substitution must be validated as described
in Step 15
12 Data Analysis and Calculations
121 Equations for activity concentration combined standard uncertainty and
radiochemical yield (if required)
1211 The activity concentration of the analyte and its combined standard
uncertainty are calculated using the following equations
aata
ttata
IDRV
IDRAAC
2
t
t
2
2
a
a
2
2
t
t
22
a2
a
2
a
2
t
2
a
2
t
2
t
2
ta
2
ac
)()()()()(
R
Ru
V
Vu
A
AuAC
IDRV
IDARuACu
ttt
tD
e
aat
aD
e
Where
ACa = activity concentration of the analyte at time of collection (or other
specified reference time) in picocuries per liter (pCiL)
At = activity of the tracer added to the sample aliquant on the tracer
solution reference datetime (pCi)
Ra = net count rate of the analyte in the defined region of interest (ROI)
in counts per second (see 1212)
Rt = net count rate of the tracer in the defined ROI in counts per second
(see 1212)
Va = volume of the sample aliquant (L)
Dt = correction factor for decay of the tracer from its reference date and
time to the midpoint of the counting period
Da = correction factor for decay of the analyte from the time of sample
collection (or other reference time) to the midpoint of the counting
period
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 14 Revision 0
It = probability of α emission in the defined ROI per decay of the tracer
(Table 171)
Ia = probability of α emission in the defined ROI per decay of the analyte
(Table 171)
uc(ACa) = combined standard uncertainty of the activity concentration of the
analyte (pCiL)
u(At) = standard uncertainty of the activity of the tracer added to the sample
(pCi)
u(Ra) = standard uncertainty of the net count rate of the analyte (sminus1
) (see
1212)
u(Rt) = standard uncertainty of the net count rate of the tracer (sminus1
) (see
1212)
u(Va) = standard uncertainty of the size of the sample aliquant volume (L)
λt = decay constant for the tracer radionuclide (sminus1
see Table 171)
λa = decay constant for the analyte radionuclide (sminus1
see Table 171)
tt = time elapsed between the activity reference date for the tracer and
the midpoint of the sample count (s)
ta = time elapsed between the activity reference date for the sample (eg
collection date) and the midpoint of the sample count (s)
NOTE The uncertainties of the decay-correction factors and of the probability of decay
factors are assumed to be negligible
NOTE The equation for the combined standard uncertainty (uc(ACa)) calculation is arranged to
eliminate the possibility of dividing by zero if Ra = 0
NOTE The standard uncertainty of the activity of the tracer added to the sample must reflect the
uncertainty associated with the activity of the standard reference material and any other
significant sources of uncertainty such as those introduced during the preparation of the tracer
solution (eg weighing or dilution factors) and during the process of adding the tracer to the
sample
1212 The net count rate of an analyte or tracer and its standard uncertainty are
calculated using the following equations
b
bx
s
xx
t
C
t
CR
and
2
b
bx
2
s
xx
11)(
t
C
t
CRu
where
Rx = net count rate of analyte or tracer in counts per second
Cx = sample counts in the analyte or the tracer ROI
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 15 Revision 0
ts = sample count time (s)
Cbx = background counts in the same ROI as for x
tb = background count time (s)
u(Rx) = standard uncertainty of the net count rate of tracer or analyte in
counts per second2
If the radiochemical yield of the tracer is requested the yield and its combined
standard uncertainty can be calculated using the following equations
ttt
t
0370 IDA
RRY
and
2
2
2
t
t
2
2
t
t
2)()()(
)(
u
A
Au
R
RuRYRYuc
where
RY = radiochemical yield of the tracer expressed as a fraction
Rt = net count rate of the tracer in counts per second
At = activity of the tracer added to the sample (pCi)
Dt = correction factor for decay of the tracer from its reference date and
time to the midpoint of the counting period
It = probability of α emission in the defined ROI per decay of the tracer
(Table 171)
ε = detector efficiency expressed as a fraction
uc(RY) = combined standard uncertainty of the radiochemical yield
u(Rt) = standard uncertainty of the net count rate of the tracer in counts per
second
u(At) = standard uncertainty of the activity of the tracer added to the sample
(pCi)
u(ε) = standard uncertainty of the detector efficiency
1213 If the critical level concentration (Lc) or the minimum detectable
concentration (MDC) are requested (at an error rate of 5) they can be
calculated using the following equations 3
2 For methods with very low counts MARLAP Section 19522 recommends adding one count each to the gross
counts and the background counts when estimating the uncertainty of the respective net counts This minimizes
negative bias in the estimate of uncertainty and protects against calculating zero uncertainty when a total of zero
counts are observed for the sample and background 3 The formulations for the critical level and minimum detectable concentration are based on the Stapleton
Approximation as recommended in MARLAP Section 20A22 Equations 2054 and 20A32 and Equation 2074
respectively (EPA 2004) The formulations presented here assume an error rate of α = 005 β = 005 (with z1minusα =
z1minusβ = 1645) and d = 04 For methods with very low numbers of counts these expressions provide better estimates
than do the traditional formulas for the critical level and MDC
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 16 Revision 0
aatas
ttt
b
s
b
sbba
b
s
b
s
cIDRVt
IDAt
t
t
ttR
t
t
t
t
L
140645116770140
aatas
ttt
b
ssba
b
s 13291271
MDCIDRVt
IDAt
ttR
t
t
where
Rba = background count rate for the analyte in the defined ROI in counts
per second
122 Results Reporting
1221 The following data should be reported for each result volume of sample
used yield of tracer and its uncertainty and FWHM of each peak used in
the analysis
1222 The following conventions should be used for each result
12221 Result in scientific notation plusmn combined standard uncertainty
13 Method Performance
131 Method validation results performed prior to analyzing samples are to be documented
and reported as required
132 Expected processing time per batch of 10-20 samples plus QC
1321 For an analysis of a 02 L sample aliquant precipitation and preparation of
load solution takes ~1 h
1322 Purification and separation using cartridges and vacuum box system should
take ~2 h
1323 The sample test source preparation step takes ~075 h
1324 A four-hour counting time should be sufficient to meet the MQOs listed in
Step 14 assuming detector efficiency of 015ndash03 and radiochemical yield
of at least 05 A different counting time may be necessary to meet these
MQOs if any of the relevant parameters are significantly different
1325 Data should be ready for reduction ~8-9 h after beginning of analysis
14 Pollution Prevention The method utilizes small volume (2 mL) extraction chromatographic
resin columns This approach leads to a significant reduction in the volumes of load rinse
and strip solutions as compared to classical methods using ion exchange resins to separate
and purify the curium fraction
15 Waste Management
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 17 Revision 0
151 Types of waste generated per sample analyzed
1511 Approximately 210 mL basic waste from the initial sample
preconcentration
1512 Approximately 65 mL of acidic waste from loading and rinsing the two
extraction columns will be generated
1513 Approximately 25 mL of acidic waste from the microprecipitation method
for source preparation will be generated The waste contains 1 mL of HF
and ~ 5 mL of ethanol
1514 TEVAreg
cartridge ndash ready for appropriate disposal
1515 DGA cartridge ndash ready for appropriate disposal
1516 These waste streams may contain low levels of 243
Am (added as tracer) 244
Cm (added to LCS) and other radionuclides as present in samples
152 Evaluate all waste streams according to disposal requirements by applicable
regulations
16 References
Cited References
161 EPA 2009 Method Validation Guide for Radiological Laboratories Participating in
Incident Response Activities Revision 0 Office of Air and Radiation Washington
(MARLAP) 2004 EPA 402-B-1304 04-001A July Volume I Chapters 6 7 20
Glossary Volume II and Volume III Appendix G Available here
163 ASTM D7282 ldquoStandard Practice for Set-up Calibration and Quality Control of
Instruments Used for Radioactivity Measurementsrdquo ASTM Book of Standards 1102
current version ASTM International West Conshohocken PA
164 ASTM D1193 ldquoStandard Specification for Reagent Waterrdquo ASTM Book of Standards
1102 current version ASTM International West Conshohocken PA
Other References
165 EPA 2012 Rapid Radiochemical Method for Americium-241 in Building Materials
for Environmental Remediation Following Radiological Incidents Office of Air and
Radiation Washington DC Available here
166 Maxwell S Culligan B and Noyes G 2010 Rapid Separation Method for Actinides
in Emergency Soil Samples Radiochimica Acta 98(12) 793-800
167 Maxwell S Culligan B Kelsey-Wall A and Shaw P 2011 ldquoRapid Radiochemical
Method for Determination of Actinides in Emergency Concrete and Brick Samplesrdquo
Analytica Chimica Acta 701(1) 112-8
168 VBS01 Rev14 ldquoSetup and Operation Instructions for Eichromrsquos Vacuum Box
System (VBS)rdquo Eichrom Technologies LLC Lisle Illinois (January 2014)
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 18 Revision 0
17 Tables Diagrams Flow Charts and Validation Data
171 Tables
Table 171 Alpha Particle Energies and Abundances of Importance[1]
Nuclide Half-Life
(Years)
λ
(sminus1
) Abundance
α Emission Energy
in kilo electron volts
244Cm
1811 1213times10
minus09
07690 5805
02310 5763
243Cm
291 755times10
minus10
00150 6066
0047 6058
0010968 6010
00568 5992
00069797 5876
0730 5785
0115 5742
0015954 5686
00019942 5682
00013959 5639 244243
Cm (combined) 1811 1213times10
minus09 1000 5805
242Cm
04462 4923times10minus08
02592 6113
07408 6069
245Cm
850times10
3 258times10
minus12
00058 5529
00083 5489
00045 5370
09320 5361
05000 5304
00032 5234
246Cm
476times10
3 461times10
minus12
0822 5387
0178 5344
247Cm
1560times10
7 1408times10
minus15
0138 5267
0057 5212
00120 5147
00200 4985
00160 4943
0710 4870
0047 4820
243Am
7370times10
3 2980times10
minus12
00016 5349
00016 5321
0871 5275
0112 5233
00136 5181 243
Am (combined) 7370times10
3 2980times10
minus12 09998 5275
241Am
4326 5078times10
minus11
00037 5545
000225 5512
0848 5486
0131 5443
001660 5388
[1] Particle energies with abundances less than 01 have been omitted unless they are contiguous with the
radionuclide region of interest
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 19 Revision 0
Data were queried from the NUDAT 2 Decay Radiation database at the Brookhaven National Laboratory National
Nuclear Data Center (httpwwwnndcbnlgovnudat2indx_decjsp) on 9192014
Table 172 Alpha Emissions Sorted by Decreasing Energy
Nuclide Half-Life
(years) λ
(sminus1
) α Emission
Energy (keV)[1]
Abundance 242
Cm 04462 4923times10-08
6113 07408 242
Cm 04462 4923times10-08
6069 02592 243
Cm 291 755times10-10
6066 00150 243
Cm 291 755times10-10
6058 0047 243
Cm 291 755times10-10
6010 0010968 243
Cm 291 755times10-10
5992 00568 243
Cm 291 755times10-10
5876 00069797 244
Cm 1811 1213times10-09
5805 07690 243
Cm 291 755times10-10
5785 0730 244
Cm 1811 1213times10-09
5763 02310 243
Cm 291 755times10-10
5742 0115 243
Cm 291 755times10-10
5686 0015954 243
Cm 291 755times10-10
5682 00019942 243
Cm 291 755times10-10
5639 00013959 241
Am 4326times102 5078times10
-11 5545 00037
245Cm 850times10
3 258times10
-12 5529 00058
241Am 4326times10
2 5078times10
-11 5512 000225
245Cm 850times10
3 258times10
-12 5489 00083
241Am 4326times10
2 5078times10
-11 5486 0848
241Am 4326times10
2 5078times10
-11 5443 0131
241Am 4326times10
2 5078times10
-11 5388 001660
246Cm 476times10
3 461times10
-12 5387 0822
245Cm 850times10
3 258times10
-12 5370 00045
245Cm 850times10
3 258times10
-12 5361 09320
243Am 7370times10
3 2980times10
-12 5349 00016
246Cm 476times10
3 461times10
-12 5344 0178
243Am 7370times10
3 2980times10
-12 5321 00016
245Cm 850times10
3 258times10
-12 5304 05000
243Am 7370times10
3 2980times10
-12 5275 0871
247Cm 1560times10
7 1408times10
-15 5267 0138
245Cm 850times10
3 258times10
-12 5234 00032
243Am 7370times10
3 2980times10
-12 5233 0112
247Cm 1560times10
7 1408times10
-15 5212 0057
247Cm 1560times10
7 1408times10
-15 5147 00120
247Cm 1560times10
7 1408times10
-15 4985 00200
247Cm 1560times10
7 1408times10
-15 4943 00160
247Cm
1560times107 1408times10
-15 4870 0710
247Cm
1560times107 1408times10
-15 4820 0047
[1]Particle energies with abundances less than 01 have been omitted unless they would be contiguous with the
radionuclide region of interest
Data were queried from the NUDAT 2 Decay Radiation database at Brookhaven National Laboratory National
Nuclear Data Center (httpwwwnndcbnlgovnudat2indx_decjsp) on 9192014
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 20 Revision 0
Ingrowth Curves and Ingrowth Factors
This section intentionally left blank
172 Spectrum from a Processed Sample
Curium-244 Spectrum
173 Decay Scheme
244Cm
240Pu
tfrac12=1811 y
tfrac12= 6561times10
3y
α
α
243Am
239Np
tfrac12=7330y
239Pu
tfrac12=619m
β
243Cm
239Pu
tfrac12=291 y
tfrac12= 2411times10
4y
α
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 21 Revision 0
174 Flow Chart
Separation Scheme and Timeline for theDetermination of 244Cm in Water Samples
Aliquant preparation batch
bull Aliquant 200 mL of each sample and QC sample into
centrifuge tubes (11111 - 11114)
bull Acidify with HNO3 to pH lt 2 (11115)
bull Add 244Cm to LCS and 243Am tracer to all samples
(11116- 11117)
Elapsed Time
1 hour
Vacuum box setup
bull Assemble TEVAreg +
DGA cartridges on
vacuum box (11131 -
11135)
bull Condition cartridges with
3M HNO3 and adjust
f low to ~1 mLmin
(11136 - 11138)
Load sample onto TEVAreg amp DGA cartridges
bull Load sample 1 mLmin (11141)
bull Add 5 mL 6M HNO3 tube rinse to column ~2 mLmin (11142)
bull Rinse column with 5 mL 6 MHNO3 ~2 mLmin (11143)
Prepare load solution adjust Pu to Pu4+
bull Dissolve Ca3(PO4)2 with 15 mL HNO3Al(NO3)3 (11121)
bull Add 05 mL 15M sulfamic acid and swirl to mix (11122)
bull Add 125 mL 15M ascorbic acid and swirl to mix and
wait 3 minutes (11123)
bull Add 1 mL 35M sodium nitrite and swirl to mix (11124)
bull Add 15 mL concentrated nitric acid and swirl to mix
(11125)
bull Discard TEVAreg cartridge and load
and rinse solutions (11144)
bull Place f resh reservoirs above each
cartridge (11144)
Continue with Step 11145
frac34 hour
Calcium phosphate preconcentration
bull Add 1 mL 15M Ca(NO3)2 3 mL 32M (NH4)2HPO4
and 2-3 drops phenolphthalein indicator (11118)
bull Add 15M NH4OH to pink phenolphthalein endpoint to
precipitate Ca3(PO4)2 and centrifuge (11119)
bull Decant supernate to waste (111110)
2 hours
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 22 Revision 0
Microprecipitation and sample test source preparation
bull Add 100 microL (50 microg) Ce carrier to each sample (1121)
bull Add 05 mL 30 wt H2O2 (1122)
bull Add 1 mL concentrated HF into each sample (1123)
bull Cap tube mix and wait 15 min (1124)
bull Set up f iltering apparatus (1125 - 1127)
bull Filter sample onto 25-mm 01-microm membrane f ilter (1128)
bull Rinse with ~2-3 mL water and allow to drain (1129)
bull Rinse with ~1-2 mL alcohol to displace water (11210-11211)
bull Mount f ilter for counting (11212)
bull Place f ilter under heat lamp under gentle heat for ~5 min (11213)
Elapsed Time
Cm separation on DGA Resin
bull Rinse column with 20 mL 01M HNO3 ~1-2 mLmin (11145)
bull Rinse column with 15 mL 3M HNO3-025M HF ~1-2 mLmin (11146)
bull Rinse column with 3 mL 4M HCl ~1-2 mLmin remove excess HCl f rom
column (11147)
bull Place f resh connector tips under each column and tubes under each column to
catch Cm (11148)
bull Elute Cm with 10 mL 025M HCl ~1 mLmin (11149)
bull Remove tubes for microprecipitation and continue with Step 112 (111410)
Discard DGA cartridge (111411)
Discard filtrates and rinses (11215)
Continue from Step 11144 2 hours
3 hours
3 frac34 hours
8 hours
Separation Scheme and Timeline for theDetermination of 244Cm in Water Samples (cont)
Count sample test sources (STS)
by alpha spectrometry for 244Cm and 243Am for
four hours or as needed to meet MQOs
(11214)
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 23 Revision 0
Appendix A Composition of Test Samples Used for Validation
Metals by ICP-MS Concentration (μgL) amp Be 0015 (J)
Na 3400
Mg 1500
Al 15 (J)
K 1500
Ca 17000
V 030 (J)
Cr 0075 (J)
Mn 63
Fe 26 (J)
Co 0047 (J)
Ni 069 (J)
Cu 59
Zn 80
As 027 (J)
Se 011 (J)
Mo lt041 (U)
Ag lt00082 (U)
Cd 0010 (J)
Sb 0060 (J)
Ba 20
Tl 0054 (J)
Pb 023 (J)
U 0010 (J)
Radionuclide Activity Concentration (pCiL) 244
Cm 0012 plusmn 0050
252250Cf 0001 plusmn 0044
241Am 020 plusmn 029
232Th
230Th
228Th
0003 plusmn 0034 amp
0052 plusmn 0081 amp
031 plusmn 012 amp
238U
235U
234U
018 plusmn 012 amp
0219 plusmn 0095 amp
0232 plusmn 0096 amp
226Ra 0049 plusmn 0024
amp
Qualifiers (U) ndash Result is less than the Instrument Detection Limit (IDL) per
SW846 Method 6020A
(J) ndash Result falls between the IDL and the reporting limit amp Mean plusmn 2 standard deviations of triplicate analyses of each of two Montgomery
Alabama tap water Mean plusmn 2 standard deviations of replicate analysis of seven samples of
Montgomery Alabama tap water
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 10 Revision 0
11112 Aliquant a second 200 mL portion of one sample into a 225-mL
centrifuge tube as a sample duplicate
11113 Add 200 mL reagent water to an empty 225-mL centrifuge tube
as a reagent blank
11114 Add 200 mL reagent water to an empty 225-mL centrifuge tube
for the LCS
11115 Acidify each sample with concentrated HNO3 to a pH of less
than 20 by adding HNO3 This usually requires about 05 mL of
HNO3
11116 Add 10-40 dpm 244
Cm standard solution to the LCS centrifuge
tube following laboratory protocol
11117 Add 10-40 dpm 243
Am tracer to the blank LCS and sample and
sample duplicates following laboratory protocol
11118 Add 1 mL of 15 M Ca(NO3)2 3 mL of 32 M (NH4)2HPO4
solution and 2ndash3 drops of phenolphthalein indicator to each
centrifuge tube
11119 Slowly add concentrated NH4OH to each centrifuge tube with a
squeeze bottle Add enough NH4OH to reach a dark pink
phenolphthalein end point and form Ca3(PO4)2 precipitate Cap
and mix tubes and centrifuge at 2000 revolutions per minute
(rpm) or more for ~5 minutes
Note If a sample aliquant larger than 200 mL is needed the aliquant may be added to
a large beaker heated on a hot plate to near boiling with reagents added and allowed
to cool and settle After pouring off enough of the supernate the precipitate may be
transferred to a 225 mL tube rinsing the beaker well with water and centrifuged
111110 Decant supernatant solution and discard to waste
1112 Preparation of the Load Solution
11121 Dissolve the calcium phosphate precipitate with 15 mL of 3 M
HNO3 - 10 M Al(NO3)3 If the residue volume is large or if
residual solids remain an additional 5 mL may be needed to
obtain complete dissolution
11122 Add 05 mL of 15 M sulfamic acid to each sample Swirl to mix
NOTE If elevated levels of 237
Np are potentially present in the sample also add 05 mL
of 4 mgmL iron carrier to enhance neptunium (Np) reduction to Np4+
The addition of
ascorbic acid in the next step will convert Fe3+
to Fe2+
and ensure removal of Np on
TEVAreg Resin
11123 Add 125 mL of 15 M ascorbic acid to each sample Swirl to
mix Wait 3 minutes
NOTE Plutonium (Pu) if present will be adjusted to Pu4+
to ensure retention and
removal on TEVAreg Resin A small amount of brown fumes results from nitrite
reaction with sulfamic acid The solution should clear with swirling If the solution
does not clear (is still dark) an additional small volume of sodium nitrite may be
added to clear the solution
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 11 Revision 0
11124 Add 1 mL of 35 M NaNO2 to each sample Swirl to mix
NOTE The load solution nitrate concentration is increased after valence adjustment to
provide greater retention of Am and more effective elution of calcium ions on DGA
Resin
11125 Add 15 mL concentrated HNO3 to each sample and swirl to mix
NOTE The steps in this section were optimized for a commercially available filtration
system Other vacuum systems may be substituted here The cartridges may be set up
and conditioned with nitric acid so that they are ready for column loading just prior
to completion of the valence adjustment steps More than one vacuum box may be
used to increase throughput
1113 Set up TEVAreg and DGA cartridges on the vacuum box system
11131 Place the inner centrifuge tube rack (supplied with vacuum box)
into the vacuum box with the centrifuge tubes in the rack Place
the lid on the vacuum box system
11132 Place the yellow outer tips into all 24 openings of the lid of the
vacuum box Fit an inner white tip into each yellow tip
11133 For each sample assemble a TEVAreg and a DGA cartridge and
lock these onto the inner white tip (DGA cartridge below
TEVAreg
)
11134 Place reservoirs on the top end of the TEVAreg cartridge
11135 Seal unused openings on the vacuum box by inserting yellow
caps included with the vacuum box into unused white tips to
achieve a good seal during the separation Alternately plastic
tape can be used to seal the unused lid holes
11136 Turn the vacuum on and ensure proper fitting of the lid
11137 Add 5 mL of 3 M HNO3 to the column reservoir to precondition
the TEVAreg cartridges
11138 Adjust the vacuum to achieve a flow-rate of ~1 mLmin
IMPORTANT Unless the method specifies otherwise use a flow rate of ~ 1 mLmin
for load and strip solutions and ~ 2 -3 mLmin for rinse solutions
1114 TEVAreg
and DGA Resin Separation
11141 Transfer each solution from Step 11125 into the appropriate
reservoir Allow solution to pass through the stacked TEVAreg +
DGA cartridge at a flow rate of ~1 mLmin
11142 Add 5 mL of 6 M HNO3 to each tubebeaker as a rinse and
transfer each solution into the appropriate reservoir (the flow rate
can be adjusted to ~2 mLmin)
11143 Add a 5 mL rinse of 6 M HNO3 to each column (the flow rate
can be adjusted to ~2 mLmin)
11144 Turn off vacuum discard rinse solutions and remove reservoirs
and TEVAreg cartridges and discard Place new reservoirs on the
DGA cartridges
11145 Add a 20 mL rinse of 01 M HNO3 to each reservoir (flow rate
~1-2 mLmin)
NOTE The rinses with dilute nitric acid remove uranium while curium
and americium are retained Precipitation of uranium during
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 12 Revision 0
microprecipitation is inhibited by adding hydrogen peroxide to ensure
uranium is present as UO22+
11146 Add 15 mL of 3 M HNO3ndash025 M HF to each reservoir at ~1-2
mLmin to complex and remove Th from the DGA Resin
11147 Add 3 mL of 4 M HCl to each reservoir at ~1ndash2 mLmin to rinse
column of residual fluoride Once the HCl has passed through the
column quickly pulse the vacuum two or three times to
minimize the amount of residual HCl in the column prior to
proceeding
11148 Ensure that clean labeled plastic tubes are placed in the tube
rack under each cartridge For maximum removal of
interferences during elution also change connector tips prior to
CmAm elution
11149 Add 10 mL of 025 M HCl solution to elute curium and
americium from each cartridge reducing the flow rate to ~1
mLmin (or slightly slower)
111410 Set the curium fraction in the plastic tube aside for cerium
fluoride coprecipitation Step 112
111411 Discard the DGA cartridge
112 Preparation of the Sample Test Source
NOTE Instructions below describe preparation of a single sample test source (STS) Several
STSs can be prepared simultaneously if a multi-channel vacuum manifold system is available
1121 Pipet 100 microL of the cerium carrier solution into each tube
1122 Pipet 05 mL 30 wt H2O2 into each tube to prevent residual uranium from
precipitating
1123 Pipet 1 mL of concentrated HF into each tube
1124 Cap the tube and mix Allow samples sit for ~ 15 minutes before filtering
1125 Set up a filter apparatus to accommodate a 01-micron 25-mm membrane
filter on a microprecipitation filtering apparatus
Caution Following deposition of the microprecipitate there is no visible difference
between the two sides of the filter
1126 If a hydrophobic filter is used add a few drops of 95 ethanol to wet each
filter and apply vacuum Ensure that there are no leaks along the sides
before proceeding
1127 While vacuum is applied add 2-3 mL of filtered Type I water to each filter
and allow the liquid to drain
1128 Add the sample to the reservoir rinsing the sample tubes with ~3 mL of
water and transfer this rinse to filter apparatus Allow to drain
1129 Wash each filter with ~2-3 mL of water and allow to drain
11210 Wash each filter with ~1-2 mL of 95 ethanol to displace water
11211 Allow to drain completely before turning the vacuum off
11212 Mount the filter on a labeled adhesive mounting disk (or equivalent)
ensuring that the filter is not wrinkled and is centered on the mounting disk
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 13 Revision 0
11213 Place the filter under a heat lamp for approximately 5 minutes or longer
until it is completely dry
11214 Count filters for an appropriate period of time by alpha spectrometry
11215 Discard the filtrate to waste for future disposal If the filtrate is to be
retained it should be stored in a plastic container since glass will be
attacked by HF
NOTE Other methods for STS preparation such as electrodeposition or
microprecipitation with neodymium fluoride may be used in lieu of the cerium
fluoride microprecipitation but any such substitution must be validated as described
in Step 15
12 Data Analysis and Calculations
121 Equations for activity concentration combined standard uncertainty and
radiochemical yield (if required)
1211 The activity concentration of the analyte and its combined standard
uncertainty are calculated using the following equations
aata
ttata
IDRV
IDRAAC
2
t
t
2
2
a
a
2
2
t
t
22
a2
a
2
a
2
t
2
a
2
t
2
t
2
ta
2
ac
)()()()()(
R
Ru
V
Vu
A
AuAC
IDRV
IDARuACu
ttt
tD
e
aat
aD
e
Where
ACa = activity concentration of the analyte at time of collection (or other
specified reference time) in picocuries per liter (pCiL)
At = activity of the tracer added to the sample aliquant on the tracer
solution reference datetime (pCi)
Ra = net count rate of the analyte in the defined region of interest (ROI)
in counts per second (see 1212)
Rt = net count rate of the tracer in the defined ROI in counts per second
(see 1212)
Va = volume of the sample aliquant (L)
Dt = correction factor for decay of the tracer from its reference date and
time to the midpoint of the counting period
Da = correction factor for decay of the analyte from the time of sample
collection (or other reference time) to the midpoint of the counting
period
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 14 Revision 0
It = probability of α emission in the defined ROI per decay of the tracer
(Table 171)
Ia = probability of α emission in the defined ROI per decay of the analyte
(Table 171)
uc(ACa) = combined standard uncertainty of the activity concentration of the
analyte (pCiL)
u(At) = standard uncertainty of the activity of the tracer added to the sample
(pCi)
u(Ra) = standard uncertainty of the net count rate of the analyte (sminus1
) (see
1212)
u(Rt) = standard uncertainty of the net count rate of the tracer (sminus1
) (see
1212)
u(Va) = standard uncertainty of the size of the sample aliquant volume (L)
λt = decay constant for the tracer radionuclide (sminus1
see Table 171)
λa = decay constant for the analyte radionuclide (sminus1
see Table 171)
tt = time elapsed between the activity reference date for the tracer and
the midpoint of the sample count (s)
ta = time elapsed between the activity reference date for the sample (eg
collection date) and the midpoint of the sample count (s)
NOTE The uncertainties of the decay-correction factors and of the probability of decay
factors are assumed to be negligible
NOTE The equation for the combined standard uncertainty (uc(ACa)) calculation is arranged to
eliminate the possibility of dividing by zero if Ra = 0
NOTE The standard uncertainty of the activity of the tracer added to the sample must reflect the
uncertainty associated with the activity of the standard reference material and any other
significant sources of uncertainty such as those introduced during the preparation of the tracer
solution (eg weighing or dilution factors) and during the process of adding the tracer to the
sample
1212 The net count rate of an analyte or tracer and its standard uncertainty are
calculated using the following equations
b
bx
s
xx
t
C
t
CR
and
2
b
bx
2
s
xx
11)(
t
C
t
CRu
where
Rx = net count rate of analyte or tracer in counts per second
Cx = sample counts in the analyte or the tracer ROI
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 15 Revision 0
ts = sample count time (s)
Cbx = background counts in the same ROI as for x
tb = background count time (s)
u(Rx) = standard uncertainty of the net count rate of tracer or analyte in
counts per second2
If the radiochemical yield of the tracer is requested the yield and its combined
standard uncertainty can be calculated using the following equations
ttt
t
0370 IDA
RRY
and
2
2
2
t
t
2
2
t
t
2)()()(
)(
u
A
Au
R
RuRYRYuc
where
RY = radiochemical yield of the tracer expressed as a fraction
Rt = net count rate of the tracer in counts per second
At = activity of the tracer added to the sample (pCi)
Dt = correction factor for decay of the tracer from its reference date and
time to the midpoint of the counting period
It = probability of α emission in the defined ROI per decay of the tracer
(Table 171)
ε = detector efficiency expressed as a fraction
uc(RY) = combined standard uncertainty of the radiochemical yield
u(Rt) = standard uncertainty of the net count rate of the tracer in counts per
second
u(At) = standard uncertainty of the activity of the tracer added to the sample
(pCi)
u(ε) = standard uncertainty of the detector efficiency
1213 If the critical level concentration (Lc) or the minimum detectable
concentration (MDC) are requested (at an error rate of 5) they can be
calculated using the following equations 3
2 For methods with very low counts MARLAP Section 19522 recommends adding one count each to the gross
counts and the background counts when estimating the uncertainty of the respective net counts This minimizes
negative bias in the estimate of uncertainty and protects against calculating zero uncertainty when a total of zero
counts are observed for the sample and background 3 The formulations for the critical level and minimum detectable concentration are based on the Stapleton
Approximation as recommended in MARLAP Section 20A22 Equations 2054 and 20A32 and Equation 2074
respectively (EPA 2004) The formulations presented here assume an error rate of α = 005 β = 005 (with z1minusα =
z1minusβ = 1645) and d = 04 For methods with very low numbers of counts these expressions provide better estimates
than do the traditional formulas for the critical level and MDC
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 16 Revision 0
aatas
ttt
b
s
b
sbba
b
s
b
s
cIDRVt
IDAt
t
t
ttR
t
t
t
t
L
140645116770140
aatas
ttt
b
ssba
b
s 13291271
MDCIDRVt
IDAt
ttR
t
t
where
Rba = background count rate for the analyte in the defined ROI in counts
per second
122 Results Reporting
1221 The following data should be reported for each result volume of sample
used yield of tracer and its uncertainty and FWHM of each peak used in
the analysis
1222 The following conventions should be used for each result
12221 Result in scientific notation plusmn combined standard uncertainty
13 Method Performance
131 Method validation results performed prior to analyzing samples are to be documented
and reported as required
132 Expected processing time per batch of 10-20 samples plus QC
1321 For an analysis of a 02 L sample aliquant precipitation and preparation of
load solution takes ~1 h
1322 Purification and separation using cartridges and vacuum box system should
take ~2 h
1323 The sample test source preparation step takes ~075 h
1324 A four-hour counting time should be sufficient to meet the MQOs listed in
Step 14 assuming detector efficiency of 015ndash03 and radiochemical yield
of at least 05 A different counting time may be necessary to meet these
MQOs if any of the relevant parameters are significantly different
1325 Data should be ready for reduction ~8-9 h after beginning of analysis
14 Pollution Prevention The method utilizes small volume (2 mL) extraction chromatographic
resin columns This approach leads to a significant reduction in the volumes of load rinse
and strip solutions as compared to classical methods using ion exchange resins to separate
and purify the curium fraction
15 Waste Management
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 17 Revision 0
151 Types of waste generated per sample analyzed
1511 Approximately 210 mL basic waste from the initial sample
preconcentration
1512 Approximately 65 mL of acidic waste from loading and rinsing the two
extraction columns will be generated
1513 Approximately 25 mL of acidic waste from the microprecipitation method
for source preparation will be generated The waste contains 1 mL of HF
and ~ 5 mL of ethanol
1514 TEVAreg
cartridge ndash ready for appropriate disposal
1515 DGA cartridge ndash ready for appropriate disposal
1516 These waste streams may contain low levels of 243
Am (added as tracer) 244
Cm (added to LCS) and other radionuclides as present in samples
152 Evaluate all waste streams according to disposal requirements by applicable
regulations
16 References
Cited References
161 EPA 2009 Method Validation Guide for Radiological Laboratories Participating in
Incident Response Activities Revision 0 Office of Air and Radiation Washington
(MARLAP) 2004 EPA 402-B-1304 04-001A July Volume I Chapters 6 7 20
Glossary Volume II and Volume III Appendix G Available here
163 ASTM D7282 ldquoStandard Practice for Set-up Calibration and Quality Control of
Instruments Used for Radioactivity Measurementsrdquo ASTM Book of Standards 1102
current version ASTM International West Conshohocken PA
164 ASTM D1193 ldquoStandard Specification for Reagent Waterrdquo ASTM Book of Standards
1102 current version ASTM International West Conshohocken PA
Other References
165 EPA 2012 Rapid Radiochemical Method for Americium-241 in Building Materials
for Environmental Remediation Following Radiological Incidents Office of Air and
Radiation Washington DC Available here
166 Maxwell S Culligan B and Noyes G 2010 Rapid Separation Method for Actinides
in Emergency Soil Samples Radiochimica Acta 98(12) 793-800
167 Maxwell S Culligan B Kelsey-Wall A and Shaw P 2011 ldquoRapid Radiochemical
Method for Determination of Actinides in Emergency Concrete and Brick Samplesrdquo
Analytica Chimica Acta 701(1) 112-8
168 VBS01 Rev14 ldquoSetup and Operation Instructions for Eichromrsquos Vacuum Box
System (VBS)rdquo Eichrom Technologies LLC Lisle Illinois (January 2014)
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 18 Revision 0
17 Tables Diagrams Flow Charts and Validation Data
171 Tables
Table 171 Alpha Particle Energies and Abundances of Importance[1]
Nuclide Half-Life
(Years)
λ
(sminus1
) Abundance
α Emission Energy
in kilo electron volts
244Cm
1811 1213times10
minus09
07690 5805
02310 5763
243Cm
291 755times10
minus10
00150 6066
0047 6058
0010968 6010
00568 5992
00069797 5876
0730 5785
0115 5742
0015954 5686
00019942 5682
00013959 5639 244243
Cm (combined) 1811 1213times10
minus09 1000 5805
242Cm
04462 4923times10minus08
02592 6113
07408 6069
245Cm
850times10
3 258times10
minus12
00058 5529
00083 5489
00045 5370
09320 5361
05000 5304
00032 5234
246Cm
476times10
3 461times10
minus12
0822 5387
0178 5344
247Cm
1560times10
7 1408times10
minus15
0138 5267
0057 5212
00120 5147
00200 4985
00160 4943
0710 4870
0047 4820
243Am
7370times10
3 2980times10
minus12
00016 5349
00016 5321
0871 5275
0112 5233
00136 5181 243
Am (combined) 7370times10
3 2980times10
minus12 09998 5275
241Am
4326 5078times10
minus11
00037 5545
000225 5512
0848 5486
0131 5443
001660 5388
[1] Particle energies with abundances less than 01 have been omitted unless they are contiguous with the
radionuclide region of interest
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 19 Revision 0
Data were queried from the NUDAT 2 Decay Radiation database at the Brookhaven National Laboratory National
Nuclear Data Center (httpwwwnndcbnlgovnudat2indx_decjsp) on 9192014
Table 172 Alpha Emissions Sorted by Decreasing Energy
Nuclide Half-Life
(years) λ
(sminus1
) α Emission
Energy (keV)[1]
Abundance 242
Cm 04462 4923times10-08
6113 07408 242
Cm 04462 4923times10-08
6069 02592 243
Cm 291 755times10-10
6066 00150 243
Cm 291 755times10-10
6058 0047 243
Cm 291 755times10-10
6010 0010968 243
Cm 291 755times10-10
5992 00568 243
Cm 291 755times10-10
5876 00069797 244
Cm 1811 1213times10-09
5805 07690 243
Cm 291 755times10-10
5785 0730 244
Cm 1811 1213times10-09
5763 02310 243
Cm 291 755times10-10
5742 0115 243
Cm 291 755times10-10
5686 0015954 243
Cm 291 755times10-10
5682 00019942 243
Cm 291 755times10-10
5639 00013959 241
Am 4326times102 5078times10
-11 5545 00037
245Cm 850times10
3 258times10
-12 5529 00058
241Am 4326times10
2 5078times10
-11 5512 000225
245Cm 850times10
3 258times10
-12 5489 00083
241Am 4326times10
2 5078times10
-11 5486 0848
241Am 4326times10
2 5078times10
-11 5443 0131
241Am 4326times10
2 5078times10
-11 5388 001660
246Cm 476times10
3 461times10
-12 5387 0822
245Cm 850times10
3 258times10
-12 5370 00045
245Cm 850times10
3 258times10
-12 5361 09320
243Am 7370times10
3 2980times10
-12 5349 00016
246Cm 476times10
3 461times10
-12 5344 0178
243Am 7370times10
3 2980times10
-12 5321 00016
245Cm 850times10
3 258times10
-12 5304 05000
243Am 7370times10
3 2980times10
-12 5275 0871
247Cm 1560times10
7 1408times10
-15 5267 0138
245Cm 850times10
3 258times10
-12 5234 00032
243Am 7370times10
3 2980times10
-12 5233 0112
247Cm 1560times10
7 1408times10
-15 5212 0057
247Cm 1560times10
7 1408times10
-15 5147 00120
247Cm 1560times10
7 1408times10
-15 4985 00200
247Cm 1560times10
7 1408times10
-15 4943 00160
247Cm
1560times107 1408times10
-15 4870 0710
247Cm
1560times107 1408times10
-15 4820 0047
[1]Particle energies with abundances less than 01 have been omitted unless they would be contiguous with the
radionuclide region of interest
Data were queried from the NUDAT 2 Decay Radiation database at Brookhaven National Laboratory National
Nuclear Data Center (httpwwwnndcbnlgovnudat2indx_decjsp) on 9192014
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 20 Revision 0
Ingrowth Curves and Ingrowth Factors
This section intentionally left blank
172 Spectrum from a Processed Sample
Curium-244 Spectrum
173 Decay Scheme
244Cm
240Pu
tfrac12=1811 y
tfrac12= 6561times10
3y
α
α
243Am
239Np
tfrac12=7330y
239Pu
tfrac12=619m
β
243Cm
239Pu
tfrac12=291 y
tfrac12= 2411times10
4y
α
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 21 Revision 0
174 Flow Chart
Separation Scheme and Timeline for theDetermination of 244Cm in Water Samples
Aliquant preparation batch
bull Aliquant 200 mL of each sample and QC sample into
centrifuge tubes (11111 - 11114)
bull Acidify with HNO3 to pH lt 2 (11115)
bull Add 244Cm to LCS and 243Am tracer to all samples
(11116- 11117)
Elapsed Time
1 hour
Vacuum box setup
bull Assemble TEVAreg +
DGA cartridges on
vacuum box (11131 -
11135)
bull Condition cartridges with
3M HNO3 and adjust
f low to ~1 mLmin
(11136 - 11138)
Load sample onto TEVAreg amp DGA cartridges
bull Load sample 1 mLmin (11141)
bull Add 5 mL 6M HNO3 tube rinse to column ~2 mLmin (11142)
bull Rinse column with 5 mL 6 MHNO3 ~2 mLmin (11143)
Prepare load solution adjust Pu to Pu4+
bull Dissolve Ca3(PO4)2 with 15 mL HNO3Al(NO3)3 (11121)
bull Add 05 mL 15M sulfamic acid and swirl to mix (11122)
bull Add 125 mL 15M ascorbic acid and swirl to mix and
wait 3 minutes (11123)
bull Add 1 mL 35M sodium nitrite and swirl to mix (11124)
bull Add 15 mL concentrated nitric acid and swirl to mix
(11125)
bull Discard TEVAreg cartridge and load
and rinse solutions (11144)
bull Place f resh reservoirs above each
cartridge (11144)
Continue with Step 11145
frac34 hour
Calcium phosphate preconcentration
bull Add 1 mL 15M Ca(NO3)2 3 mL 32M (NH4)2HPO4
and 2-3 drops phenolphthalein indicator (11118)
bull Add 15M NH4OH to pink phenolphthalein endpoint to
precipitate Ca3(PO4)2 and centrifuge (11119)
bull Decant supernate to waste (111110)
2 hours
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 22 Revision 0
Microprecipitation and sample test source preparation
bull Add 100 microL (50 microg) Ce carrier to each sample (1121)
bull Add 05 mL 30 wt H2O2 (1122)
bull Add 1 mL concentrated HF into each sample (1123)
bull Cap tube mix and wait 15 min (1124)
bull Set up f iltering apparatus (1125 - 1127)
bull Filter sample onto 25-mm 01-microm membrane f ilter (1128)
bull Rinse with ~2-3 mL water and allow to drain (1129)
bull Rinse with ~1-2 mL alcohol to displace water (11210-11211)
bull Mount f ilter for counting (11212)
bull Place f ilter under heat lamp under gentle heat for ~5 min (11213)
Elapsed Time
Cm separation on DGA Resin
bull Rinse column with 20 mL 01M HNO3 ~1-2 mLmin (11145)
bull Rinse column with 15 mL 3M HNO3-025M HF ~1-2 mLmin (11146)
bull Rinse column with 3 mL 4M HCl ~1-2 mLmin remove excess HCl f rom
column (11147)
bull Place f resh connector tips under each column and tubes under each column to
catch Cm (11148)
bull Elute Cm with 10 mL 025M HCl ~1 mLmin (11149)
bull Remove tubes for microprecipitation and continue with Step 112 (111410)
Discard DGA cartridge (111411)
Discard filtrates and rinses (11215)
Continue from Step 11144 2 hours
3 hours
3 frac34 hours
8 hours
Separation Scheme and Timeline for theDetermination of 244Cm in Water Samples (cont)
Count sample test sources (STS)
by alpha spectrometry for 244Cm and 243Am for
four hours or as needed to meet MQOs
(11214)
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 23 Revision 0
Appendix A Composition of Test Samples Used for Validation
Metals by ICP-MS Concentration (μgL) amp Be 0015 (J)
Na 3400
Mg 1500
Al 15 (J)
K 1500
Ca 17000
V 030 (J)
Cr 0075 (J)
Mn 63
Fe 26 (J)
Co 0047 (J)
Ni 069 (J)
Cu 59
Zn 80
As 027 (J)
Se 011 (J)
Mo lt041 (U)
Ag lt00082 (U)
Cd 0010 (J)
Sb 0060 (J)
Ba 20
Tl 0054 (J)
Pb 023 (J)
U 0010 (J)
Radionuclide Activity Concentration (pCiL) 244
Cm 0012 plusmn 0050
252250Cf 0001 plusmn 0044
241Am 020 plusmn 029
232Th
230Th
228Th
0003 plusmn 0034 amp
0052 plusmn 0081 amp
031 plusmn 012 amp
238U
235U
234U
018 plusmn 012 amp
0219 plusmn 0095 amp
0232 plusmn 0096 amp
226Ra 0049 plusmn 0024
amp
Qualifiers (U) ndash Result is less than the Instrument Detection Limit (IDL) per
SW846 Method 6020A
(J) ndash Result falls between the IDL and the reporting limit amp Mean plusmn 2 standard deviations of triplicate analyses of each of two Montgomery
Alabama tap water Mean plusmn 2 standard deviations of replicate analysis of seven samples of
Montgomery Alabama tap water
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 11 Revision 0
11124 Add 1 mL of 35 M NaNO2 to each sample Swirl to mix
NOTE The load solution nitrate concentration is increased after valence adjustment to
provide greater retention of Am and more effective elution of calcium ions on DGA
Resin
11125 Add 15 mL concentrated HNO3 to each sample and swirl to mix
NOTE The steps in this section were optimized for a commercially available filtration
system Other vacuum systems may be substituted here The cartridges may be set up
and conditioned with nitric acid so that they are ready for column loading just prior
to completion of the valence adjustment steps More than one vacuum box may be
used to increase throughput
1113 Set up TEVAreg and DGA cartridges on the vacuum box system
11131 Place the inner centrifuge tube rack (supplied with vacuum box)
into the vacuum box with the centrifuge tubes in the rack Place
the lid on the vacuum box system
11132 Place the yellow outer tips into all 24 openings of the lid of the
vacuum box Fit an inner white tip into each yellow tip
11133 For each sample assemble a TEVAreg and a DGA cartridge and
lock these onto the inner white tip (DGA cartridge below
TEVAreg
)
11134 Place reservoirs on the top end of the TEVAreg cartridge
11135 Seal unused openings on the vacuum box by inserting yellow
caps included with the vacuum box into unused white tips to
achieve a good seal during the separation Alternately plastic
tape can be used to seal the unused lid holes
11136 Turn the vacuum on and ensure proper fitting of the lid
11137 Add 5 mL of 3 M HNO3 to the column reservoir to precondition
the TEVAreg cartridges
11138 Adjust the vacuum to achieve a flow-rate of ~1 mLmin
IMPORTANT Unless the method specifies otherwise use a flow rate of ~ 1 mLmin
for load and strip solutions and ~ 2 -3 mLmin for rinse solutions
1114 TEVAreg
and DGA Resin Separation
11141 Transfer each solution from Step 11125 into the appropriate
reservoir Allow solution to pass through the stacked TEVAreg +
DGA cartridge at a flow rate of ~1 mLmin
11142 Add 5 mL of 6 M HNO3 to each tubebeaker as a rinse and
transfer each solution into the appropriate reservoir (the flow rate
can be adjusted to ~2 mLmin)
11143 Add a 5 mL rinse of 6 M HNO3 to each column (the flow rate
can be adjusted to ~2 mLmin)
11144 Turn off vacuum discard rinse solutions and remove reservoirs
and TEVAreg cartridges and discard Place new reservoirs on the
DGA cartridges
11145 Add a 20 mL rinse of 01 M HNO3 to each reservoir (flow rate
~1-2 mLmin)
NOTE The rinses with dilute nitric acid remove uranium while curium
and americium are retained Precipitation of uranium during
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 12 Revision 0
microprecipitation is inhibited by adding hydrogen peroxide to ensure
uranium is present as UO22+
11146 Add 15 mL of 3 M HNO3ndash025 M HF to each reservoir at ~1-2
mLmin to complex and remove Th from the DGA Resin
11147 Add 3 mL of 4 M HCl to each reservoir at ~1ndash2 mLmin to rinse
column of residual fluoride Once the HCl has passed through the
column quickly pulse the vacuum two or three times to
minimize the amount of residual HCl in the column prior to
proceeding
11148 Ensure that clean labeled plastic tubes are placed in the tube
rack under each cartridge For maximum removal of
interferences during elution also change connector tips prior to
CmAm elution
11149 Add 10 mL of 025 M HCl solution to elute curium and
americium from each cartridge reducing the flow rate to ~1
mLmin (or slightly slower)
111410 Set the curium fraction in the plastic tube aside for cerium
fluoride coprecipitation Step 112
111411 Discard the DGA cartridge
112 Preparation of the Sample Test Source
NOTE Instructions below describe preparation of a single sample test source (STS) Several
STSs can be prepared simultaneously if a multi-channel vacuum manifold system is available
1121 Pipet 100 microL of the cerium carrier solution into each tube
1122 Pipet 05 mL 30 wt H2O2 into each tube to prevent residual uranium from
precipitating
1123 Pipet 1 mL of concentrated HF into each tube
1124 Cap the tube and mix Allow samples sit for ~ 15 minutes before filtering
1125 Set up a filter apparatus to accommodate a 01-micron 25-mm membrane
filter on a microprecipitation filtering apparatus
Caution Following deposition of the microprecipitate there is no visible difference
between the two sides of the filter
1126 If a hydrophobic filter is used add a few drops of 95 ethanol to wet each
filter and apply vacuum Ensure that there are no leaks along the sides
before proceeding
1127 While vacuum is applied add 2-3 mL of filtered Type I water to each filter
and allow the liquid to drain
1128 Add the sample to the reservoir rinsing the sample tubes with ~3 mL of
water and transfer this rinse to filter apparatus Allow to drain
1129 Wash each filter with ~2-3 mL of water and allow to drain
11210 Wash each filter with ~1-2 mL of 95 ethanol to displace water
11211 Allow to drain completely before turning the vacuum off
11212 Mount the filter on a labeled adhesive mounting disk (or equivalent)
ensuring that the filter is not wrinkled and is centered on the mounting disk
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 13 Revision 0
11213 Place the filter under a heat lamp for approximately 5 minutes or longer
until it is completely dry
11214 Count filters for an appropriate period of time by alpha spectrometry
11215 Discard the filtrate to waste for future disposal If the filtrate is to be
retained it should be stored in a plastic container since glass will be
attacked by HF
NOTE Other methods for STS preparation such as electrodeposition or
microprecipitation with neodymium fluoride may be used in lieu of the cerium
fluoride microprecipitation but any such substitution must be validated as described
in Step 15
12 Data Analysis and Calculations
121 Equations for activity concentration combined standard uncertainty and
radiochemical yield (if required)
1211 The activity concentration of the analyte and its combined standard
uncertainty are calculated using the following equations
aata
ttata
IDRV
IDRAAC
2
t
t
2
2
a
a
2
2
t
t
22
a2
a
2
a
2
t
2
a
2
t
2
t
2
ta
2
ac
)()()()()(
R
Ru
V
Vu
A
AuAC
IDRV
IDARuACu
ttt
tD
e
aat
aD
e
Where
ACa = activity concentration of the analyte at time of collection (or other
specified reference time) in picocuries per liter (pCiL)
At = activity of the tracer added to the sample aliquant on the tracer
solution reference datetime (pCi)
Ra = net count rate of the analyte in the defined region of interest (ROI)
in counts per second (see 1212)
Rt = net count rate of the tracer in the defined ROI in counts per second
(see 1212)
Va = volume of the sample aliquant (L)
Dt = correction factor for decay of the tracer from its reference date and
time to the midpoint of the counting period
Da = correction factor for decay of the analyte from the time of sample
collection (or other reference time) to the midpoint of the counting
period
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 14 Revision 0
It = probability of α emission in the defined ROI per decay of the tracer
(Table 171)
Ia = probability of α emission in the defined ROI per decay of the analyte
(Table 171)
uc(ACa) = combined standard uncertainty of the activity concentration of the
analyte (pCiL)
u(At) = standard uncertainty of the activity of the tracer added to the sample
(pCi)
u(Ra) = standard uncertainty of the net count rate of the analyte (sminus1
) (see
1212)
u(Rt) = standard uncertainty of the net count rate of the tracer (sminus1
) (see
1212)
u(Va) = standard uncertainty of the size of the sample aliquant volume (L)
λt = decay constant for the tracer radionuclide (sminus1
see Table 171)
λa = decay constant for the analyte radionuclide (sminus1
see Table 171)
tt = time elapsed between the activity reference date for the tracer and
the midpoint of the sample count (s)
ta = time elapsed between the activity reference date for the sample (eg
collection date) and the midpoint of the sample count (s)
NOTE The uncertainties of the decay-correction factors and of the probability of decay
factors are assumed to be negligible
NOTE The equation for the combined standard uncertainty (uc(ACa)) calculation is arranged to
eliminate the possibility of dividing by zero if Ra = 0
NOTE The standard uncertainty of the activity of the tracer added to the sample must reflect the
uncertainty associated with the activity of the standard reference material and any other
significant sources of uncertainty such as those introduced during the preparation of the tracer
solution (eg weighing or dilution factors) and during the process of adding the tracer to the
sample
1212 The net count rate of an analyte or tracer and its standard uncertainty are
calculated using the following equations
b
bx
s
xx
t
C
t
CR
and
2
b
bx
2
s
xx
11)(
t
C
t
CRu
where
Rx = net count rate of analyte or tracer in counts per second
Cx = sample counts in the analyte or the tracer ROI
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 15 Revision 0
ts = sample count time (s)
Cbx = background counts in the same ROI as for x
tb = background count time (s)
u(Rx) = standard uncertainty of the net count rate of tracer or analyte in
counts per second2
If the radiochemical yield of the tracer is requested the yield and its combined
standard uncertainty can be calculated using the following equations
ttt
t
0370 IDA
RRY
and
2
2
2
t
t
2
2
t
t
2)()()(
)(
u
A
Au
R
RuRYRYuc
where
RY = radiochemical yield of the tracer expressed as a fraction
Rt = net count rate of the tracer in counts per second
At = activity of the tracer added to the sample (pCi)
Dt = correction factor for decay of the tracer from its reference date and
time to the midpoint of the counting period
It = probability of α emission in the defined ROI per decay of the tracer
(Table 171)
ε = detector efficiency expressed as a fraction
uc(RY) = combined standard uncertainty of the radiochemical yield
u(Rt) = standard uncertainty of the net count rate of the tracer in counts per
second
u(At) = standard uncertainty of the activity of the tracer added to the sample
(pCi)
u(ε) = standard uncertainty of the detector efficiency
1213 If the critical level concentration (Lc) or the minimum detectable
concentration (MDC) are requested (at an error rate of 5) they can be
calculated using the following equations 3
2 For methods with very low counts MARLAP Section 19522 recommends adding one count each to the gross
counts and the background counts when estimating the uncertainty of the respective net counts This minimizes
negative bias in the estimate of uncertainty and protects against calculating zero uncertainty when a total of zero
counts are observed for the sample and background 3 The formulations for the critical level and minimum detectable concentration are based on the Stapleton
Approximation as recommended in MARLAP Section 20A22 Equations 2054 and 20A32 and Equation 2074
respectively (EPA 2004) The formulations presented here assume an error rate of α = 005 β = 005 (with z1minusα =
z1minusβ = 1645) and d = 04 For methods with very low numbers of counts these expressions provide better estimates
than do the traditional formulas for the critical level and MDC
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 16 Revision 0
aatas
ttt
b
s
b
sbba
b
s
b
s
cIDRVt
IDAt
t
t
ttR
t
t
t
t
L
140645116770140
aatas
ttt
b
ssba
b
s 13291271
MDCIDRVt
IDAt
ttR
t
t
where
Rba = background count rate for the analyte in the defined ROI in counts
per second
122 Results Reporting
1221 The following data should be reported for each result volume of sample
used yield of tracer and its uncertainty and FWHM of each peak used in
the analysis
1222 The following conventions should be used for each result
12221 Result in scientific notation plusmn combined standard uncertainty
13 Method Performance
131 Method validation results performed prior to analyzing samples are to be documented
and reported as required
132 Expected processing time per batch of 10-20 samples plus QC
1321 For an analysis of a 02 L sample aliquant precipitation and preparation of
load solution takes ~1 h
1322 Purification and separation using cartridges and vacuum box system should
take ~2 h
1323 The sample test source preparation step takes ~075 h
1324 A four-hour counting time should be sufficient to meet the MQOs listed in
Step 14 assuming detector efficiency of 015ndash03 and radiochemical yield
of at least 05 A different counting time may be necessary to meet these
MQOs if any of the relevant parameters are significantly different
1325 Data should be ready for reduction ~8-9 h after beginning of analysis
14 Pollution Prevention The method utilizes small volume (2 mL) extraction chromatographic
resin columns This approach leads to a significant reduction in the volumes of load rinse
and strip solutions as compared to classical methods using ion exchange resins to separate
and purify the curium fraction
15 Waste Management
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 17 Revision 0
151 Types of waste generated per sample analyzed
1511 Approximately 210 mL basic waste from the initial sample
preconcentration
1512 Approximately 65 mL of acidic waste from loading and rinsing the two
extraction columns will be generated
1513 Approximately 25 mL of acidic waste from the microprecipitation method
for source preparation will be generated The waste contains 1 mL of HF
and ~ 5 mL of ethanol
1514 TEVAreg
cartridge ndash ready for appropriate disposal
1515 DGA cartridge ndash ready for appropriate disposal
1516 These waste streams may contain low levels of 243
Am (added as tracer) 244
Cm (added to LCS) and other radionuclides as present in samples
152 Evaluate all waste streams according to disposal requirements by applicable
regulations
16 References
Cited References
161 EPA 2009 Method Validation Guide for Radiological Laboratories Participating in
Incident Response Activities Revision 0 Office of Air and Radiation Washington
(MARLAP) 2004 EPA 402-B-1304 04-001A July Volume I Chapters 6 7 20
Glossary Volume II and Volume III Appendix G Available here
163 ASTM D7282 ldquoStandard Practice for Set-up Calibration and Quality Control of
Instruments Used for Radioactivity Measurementsrdquo ASTM Book of Standards 1102
current version ASTM International West Conshohocken PA
164 ASTM D1193 ldquoStandard Specification for Reagent Waterrdquo ASTM Book of Standards
1102 current version ASTM International West Conshohocken PA
Other References
165 EPA 2012 Rapid Radiochemical Method for Americium-241 in Building Materials
for Environmental Remediation Following Radiological Incidents Office of Air and
Radiation Washington DC Available here
166 Maxwell S Culligan B and Noyes G 2010 Rapid Separation Method for Actinides
in Emergency Soil Samples Radiochimica Acta 98(12) 793-800
167 Maxwell S Culligan B Kelsey-Wall A and Shaw P 2011 ldquoRapid Radiochemical
Method for Determination of Actinides in Emergency Concrete and Brick Samplesrdquo
Analytica Chimica Acta 701(1) 112-8
168 VBS01 Rev14 ldquoSetup and Operation Instructions for Eichromrsquos Vacuum Box
System (VBS)rdquo Eichrom Technologies LLC Lisle Illinois (January 2014)
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 18 Revision 0
17 Tables Diagrams Flow Charts and Validation Data
171 Tables
Table 171 Alpha Particle Energies and Abundances of Importance[1]
Nuclide Half-Life
(Years)
λ
(sminus1
) Abundance
α Emission Energy
in kilo electron volts
244Cm
1811 1213times10
minus09
07690 5805
02310 5763
243Cm
291 755times10
minus10
00150 6066
0047 6058
0010968 6010
00568 5992
00069797 5876
0730 5785
0115 5742
0015954 5686
00019942 5682
00013959 5639 244243
Cm (combined) 1811 1213times10
minus09 1000 5805
242Cm
04462 4923times10minus08
02592 6113
07408 6069
245Cm
850times10
3 258times10
minus12
00058 5529
00083 5489
00045 5370
09320 5361
05000 5304
00032 5234
246Cm
476times10
3 461times10
minus12
0822 5387
0178 5344
247Cm
1560times10
7 1408times10
minus15
0138 5267
0057 5212
00120 5147
00200 4985
00160 4943
0710 4870
0047 4820
243Am
7370times10
3 2980times10
minus12
00016 5349
00016 5321
0871 5275
0112 5233
00136 5181 243
Am (combined) 7370times10
3 2980times10
minus12 09998 5275
241Am
4326 5078times10
minus11
00037 5545
000225 5512
0848 5486
0131 5443
001660 5388
[1] Particle energies with abundances less than 01 have been omitted unless they are contiguous with the
radionuclide region of interest
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 19 Revision 0
Data were queried from the NUDAT 2 Decay Radiation database at the Brookhaven National Laboratory National
Nuclear Data Center (httpwwwnndcbnlgovnudat2indx_decjsp) on 9192014
Table 172 Alpha Emissions Sorted by Decreasing Energy
Nuclide Half-Life
(years) λ
(sminus1
) α Emission
Energy (keV)[1]
Abundance 242
Cm 04462 4923times10-08
6113 07408 242
Cm 04462 4923times10-08
6069 02592 243
Cm 291 755times10-10
6066 00150 243
Cm 291 755times10-10
6058 0047 243
Cm 291 755times10-10
6010 0010968 243
Cm 291 755times10-10
5992 00568 243
Cm 291 755times10-10
5876 00069797 244
Cm 1811 1213times10-09
5805 07690 243
Cm 291 755times10-10
5785 0730 244
Cm 1811 1213times10-09
5763 02310 243
Cm 291 755times10-10
5742 0115 243
Cm 291 755times10-10
5686 0015954 243
Cm 291 755times10-10
5682 00019942 243
Cm 291 755times10-10
5639 00013959 241
Am 4326times102 5078times10
-11 5545 00037
245Cm 850times10
3 258times10
-12 5529 00058
241Am 4326times10
2 5078times10
-11 5512 000225
245Cm 850times10
3 258times10
-12 5489 00083
241Am 4326times10
2 5078times10
-11 5486 0848
241Am 4326times10
2 5078times10
-11 5443 0131
241Am 4326times10
2 5078times10
-11 5388 001660
246Cm 476times10
3 461times10
-12 5387 0822
245Cm 850times10
3 258times10
-12 5370 00045
245Cm 850times10
3 258times10
-12 5361 09320
243Am 7370times10
3 2980times10
-12 5349 00016
246Cm 476times10
3 461times10
-12 5344 0178
243Am 7370times10
3 2980times10
-12 5321 00016
245Cm 850times10
3 258times10
-12 5304 05000
243Am 7370times10
3 2980times10
-12 5275 0871
247Cm 1560times10
7 1408times10
-15 5267 0138
245Cm 850times10
3 258times10
-12 5234 00032
243Am 7370times10
3 2980times10
-12 5233 0112
247Cm 1560times10
7 1408times10
-15 5212 0057
247Cm 1560times10
7 1408times10
-15 5147 00120
247Cm 1560times10
7 1408times10
-15 4985 00200
247Cm 1560times10
7 1408times10
-15 4943 00160
247Cm
1560times107 1408times10
-15 4870 0710
247Cm
1560times107 1408times10
-15 4820 0047
[1]Particle energies with abundances less than 01 have been omitted unless they would be contiguous with the
radionuclide region of interest
Data were queried from the NUDAT 2 Decay Radiation database at Brookhaven National Laboratory National
Nuclear Data Center (httpwwwnndcbnlgovnudat2indx_decjsp) on 9192014
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 20 Revision 0
Ingrowth Curves and Ingrowth Factors
This section intentionally left blank
172 Spectrum from a Processed Sample
Curium-244 Spectrum
173 Decay Scheme
244Cm
240Pu
tfrac12=1811 y
tfrac12= 6561times10
3y
α
α
243Am
239Np
tfrac12=7330y
239Pu
tfrac12=619m
β
243Cm
239Pu
tfrac12=291 y
tfrac12= 2411times10
4y
α
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 21 Revision 0
174 Flow Chart
Separation Scheme and Timeline for theDetermination of 244Cm in Water Samples
Aliquant preparation batch
bull Aliquant 200 mL of each sample and QC sample into
centrifuge tubes (11111 - 11114)
bull Acidify with HNO3 to pH lt 2 (11115)
bull Add 244Cm to LCS and 243Am tracer to all samples
(11116- 11117)
Elapsed Time
1 hour
Vacuum box setup
bull Assemble TEVAreg +
DGA cartridges on
vacuum box (11131 -
11135)
bull Condition cartridges with
3M HNO3 and adjust
f low to ~1 mLmin
(11136 - 11138)
Load sample onto TEVAreg amp DGA cartridges
bull Load sample 1 mLmin (11141)
bull Add 5 mL 6M HNO3 tube rinse to column ~2 mLmin (11142)
bull Rinse column with 5 mL 6 MHNO3 ~2 mLmin (11143)
Prepare load solution adjust Pu to Pu4+
bull Dissolve Ca3(PO4)2 with 15 mL HNO3Al(NO3)3 (11121)
bull Add 05 mL 15M sulfamic acid and swirl to mix (11122)
bull Add 125 mL 15M ascorbic acid and swirl to mix and
wait 3 minutes (11123)
bull Add 1 mL 35M sodium nitrite and swirl to mix (11124)
bull Add 15 mL concentrated nitric acid and swirl to mix
(11125)
bull Discard TEVAreg cartridge and load
and rinse solutions (11144)
bull Place f resh reservoirs above each
cartridge (11144)
Continue with Step 11145
frac34 hour
Calcium phosphate preconcentration
bull Add 1 mL 15M Ca(NO3)2 3 mL 32M (NH4)2HPO4
and 2-3 drops phenolphthalein indicator (11118)
bull Add 15M NH4OH to pink phenolphthalein endpoint to
precipitate Ca3(PO4)2 and centrifuge (11119)
bull Decant supernate to waste (111110)
2 hours
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 22 Revision 0
Microprecipitation and sample test source preparation
bull Add 100 microL (50 microg) Ce carrier to each sample (1121)
bull Add 05 mL 30 wt H2O2 (1122)
bull Add 1 mL concentrated HF into each sample (1123)
bull Cap tube mix and wait 15 min (1124)
bull Set up f iltering apparatus (1125 - 1127)
bull Filter sample onto 25-mm 01-microm membrane f ilter (1128)
bull Rinse with ~2-3 mL water and allow to drain (1129)
bull Rinse with ~1-2 mL alcohol to displace water (11210-11211)
bull Mount f ilter for counting (11212)
bull Place f ilter under heat lamp under gentle heat for ~5 min (11213)
Elapsed Time
Cm separation on DGA Resin
bull Rinse column with 20 mL 01M HNO3 ~1-2 mLmin (11145)
bull Rinse column with 15 mL 3M HNO3-025M HF ~1-2 mLmin (11146)
bull Rinse column with 3 mL 4M HCl ~1-2 mLmin remove excess HCl f rom
column (11147)
bull Place f resh connector tips under each column and tubes under each column to
catch Cm (11148)
bull Elute Cm with 10 mL 025M HCl ~1 mLmin (11149)
bull Remove tubes for microprecipitation and continue with Step 112 (111410)
Discard DGA cartridge (111411)
Discard filtrates and rinses (11215)
Continue from Step 11144 2 hours
3 hours
3 frac34 hours
8 hours
Separation Scheme and Timeline for theDetermination of 244Cm in Water Samples (cont)
Count sample test sources (STS)
by alpha spectrometry for 244Cm and 243Am for
four hours or as needed to meet MQOs
(11214)
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 23 Revision 0
Appendix A Composition of Test Samples Used for Validation
Metals by ICP-MS Concentration (μgL) amp Be 0015 (J)
Na 3400
Mg 1500
Al 15 (J)
K 1500
Ca 17000
V 030 (J)
Cr 0075 (J)
Mn 63
Fe 26 (J)
Co 0047 (J)
Ni 069 (J)
Cu 59
Zn 80
As 027 (J)
Se 011 (J)
Mo lt041 (U)
Ag lt00082 (U)
Cd 0010 (J)
Sb 0060 (J)
Ba 20
Tl 0054 (J)
Pb 023 (J)
U 0010 (J)
Radionuclide Activity Concentration (pCiL) 244
Cm 0012 plusmn 0050
252250Cf 0001 plusmn 0044
241Am 020 plusmn 029
232Th
230Th
228Th
0003 plusmn 0034 amp
0052 plusmn 0081 amp
031 plusmn 012 amp
238U
235U
234U
018 plusmn 012 amp
0219 plusmn 0095 amp
0232 plusmn 0096 amp
226Ra 0049 plusmn 0024
amp
Qualifiers (U) ndash Result is less than the Instrument Detection Limit (IDL) per
SW846 Method 6020A
(J) ndash Result falls between the IDL and the reporting limit amp Mean plusmn 2 standard deviations of triplicate analyses of each of two Montgomery
Alabama tap water Mean plusmn 2 standard deviations of replicate analysis of seven samples of
Montgomery Alabama tap water
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 12 Revision 0
microprecipitation is inhibited by adding hydrogen peroxide to ensure
uranium is present as UO22+
11146 Add 15 mL of 3 M HNO3ndash025 M HF to each reservoir at ~1-2
mLmin to complex and remove Th from the DGA Resin
11147 Add 3 mL of 4 M HCl to each reservoir at ~1ndash2 mLmin to rinse
column of residual fluoride Once the HCl has passed through the
column quickly pulse the vacuum two or three times to
minimize the amount of residual HCl in the column prior to
proceeding
11148 Ensure that clean labeled plastic tubes are placed in the tube
rack under each cartridge For maximum removal of
interferences during elution also change connector tips prior to
CmAm elution
11149 Add 10 mL of 025 M HCl solution to elute curium and
americium from each cartridge reducing the flow rate to ~1
mLmin (or slightly slower)
111410 Set the curium fraction in the plastic tube aside for cerium
fluoride coprecipitation Step 112
111411 Discard the DGA cartridge
112 Preparation of the Sample Test Source
NOTE Instructions below describe preparation of a single sample test source (STS) Several
STSs can be prepared simultaneously if a multi-channel vacuum manifold system is available
1121 Pipet 100 microL of the cerium carrier solution into each tube
1122 Pipet 05 mL 30 wt H2O2 into each tube to prevent residual uranium from
precipitating
1123 Pipet 1 mL of concentrated HF into each tube
1124 Cap the tube and mix Allow samples sit for ~ 15 minutes before filtering
1125 Set up a filter apparatus to accommodate a 01-micron 25-mm membrane
filter on a microprecipitation filtering apparatus
Caution Following deposition of the microprecipitate there is no visible difference
between the two sides of the filter
1126 If a hydrophobic filter is used add a few drops of 95 ethanol to wet each
filter and apply vacuum Ensure that there are no leaks along the sides
before proceeding
1127 While vacuum is applied add 2-3 mL of filtered Type I water to each filter
and allow the liquid to drain
1128 Add the sample to the reservoir rinsing the sample tubes with ~3 mL of
water and transfer this rinse to filter apparatus Allow to drain
1129 Wash each filter with ~2-3 mL of water and allow to drain
11210 Wash each filter with ~1-2 mL of 95 ethanol to displace water
11211 Allow to drain completely before turning the vacuum off
11212 Mount the filter on a labeled adhesive mounting disk (or equivalent)
ensuring that the filter is not wrinkled and is centered on the mounting disk
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 13 Revision 0
11213 Place the filter under a heat lamp for approximately 5 minutes or longer
until it is completely dry
11214 Count filters for an appropriate period of time by alpha spectrometry
11215 Discard the filtrate to waste for future disposal If the filtrate is to be
retained it should be stored in a plastic container since glass will be
attacked by HF
NOTE Other methods for STS preparation such as electrodeposition or
microprecipitation with neodymium fluoride may be used in lieu of the cerium
fluoride microprecipitation but any such substitution must be validated as described
in Step 15
12 Data Analysis and Calculations
121 Equations for activity concentration combined standard uncertainty and
radiochemical yield (if required)
1211 The activity concentration of the analyte and its combined standard
uncertainty are calculated using the following equations
aata
ttata
IDRV
IDRAAC
2
t
t
2
2
a
a
2
2
t
t
22
a2
a
2
a
2
t
2
a
2
t
2
t
2
ta
2
ac
)()()()()(
R
Ru
V
Vu
A
AuAC
IDRV
IDARuACu
ttt
tD
e
aat
aD
e
Where
ACa = activity concentration of the analyte at time of collection (or other
specified reference time) in picocuries per liter (pCiL)
At = activity of the tracer added to the sample aliquant on the tracer
solution reference datetime (pCi)
Ra = net count rate of the analyte in the defined region of interest (ROI)
in counts per second (see 1212)
Rt = net count rate of the tracer in the defined ROI in counts per second
(see 1212)
Va = volume of the sample aliquant (L)
Dt = correction factor for decay of the tracer from its reference date and
time to the midpoint of the counting period
Da = correction factor for decay of the analyte from the time of sample
collection (or other reference time) to the midpoint of the counting
period
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 14 Revision 0
It = probability of α emission in the defined ROI per decay of the tracer
(Table 171)
Ia = probability of α emission in the defined ROI per decay of the analyte
(Table 171)
uc(ACa) = combined standard uncertainty of the activity concentration of the
analyte (pCiL)
u(At) = standard uncertainty of the activity of the tracer added to the sample
(pCi)
u(Ra) = standard uncertainty of the net count rate of the analyte (sminus1
) (see
1212)
u(Rt) = standard uncertainty of the net count rate of the tracer (sminus1
) (see
1212)
u(Va) = standard uncertainty of the size of the sample aliquant volume (L)
λt = decay constant for the tracer radionuclide (sminus1
see Table 171)
λa = decay constant for the analyte radionuclide (sminus1
see Table 171)
tt = time elapsed between the activity reference date for the tracer and
the midpoint of the sample count (s)
ta = time elapsed between the activity reference date for the sample (eg
collection date) and the midpoint of the sample count (s)
NOTE The uncertainties of the decay-correction factors and of the probability of decay
factors are assumed to be negligible
NOTE The equation for the combined standard uncertainty (uc(ACa)) calculation is arranged to
eliminate the possibility of dividing by zero if Ra = 0
NOTE The standard uncertainty of the activity of the tracer added to the sample must reflect the
uncertainty associated with the activity of the standard reference material and any other
significant sources of uncertainty such as those introduced during the preparation of the tracer
solution (eg weighing or dilution factors) and during the process of adding the tracer to the
sample
1212 The net count rate of an analyte or tracer and its standard uncertainty are
calculated using the following equations
b
bx
s
xx
t
C
t
CR
and
2
b
bx
2
s
xx
11)(
t
C
t
CRu
where
Rx = net count rate of analyte or tracer in counts per second
Cx = sample counts in the analyte or the tracer ROI
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 15 Revision 0
ts = sample count time (s)
Cbx = background counts in the same ROI as for x
tb = background count time (s)
u(Rx) = standard uncertainty of the net count rate of tracer or analyte in
counts per second2
If the radiochemical yield of the tracer is requested the yield and its combined
standard uncertainty can be calculated using the following equations
ttt
t
0370 IDA
RRY
and
2
2
2
t
t
2
2
t
t
2)()()(
)(
u
A
Au
R
RuRYRYuc
where
RY = radiochemical yield of the tracer expressed as a fraction
Rt = net count rate of the tracer in counts per second
At = activity of the tracer added to the sample (pCi)
Dt = correction factor for decay of the tracer from its reference date and
time to the midpoint of the counting period
It = probability of α emission in the defined ROI per decay of the tracer
(Table 171)
ε = detector efficiency expressed as a fraction
uc(RY) = combined standard uncertainty of the radiochemical yield
u(Rt) = standard uncertainty of the net count rate of the tracer in counts per
second
u(At) = standard uncertainty of the activity of the tracer added to the sample
(pCi)
u(ε) = standard uncertainty of the detector efficiency
1213 If the critical level concentration (Lc) or the minimum detectable
concentration (MDC) are requested (at an error rate of 5) they can be
calculated using the following equations 3
2 For methods with very low counts MARLAP Section 19522 recommends adding one count each to the gross
counts and the background counts when estimating the uncertainty of the respective net counts This minimizes
negative bias in the estimate of uncertainty and protects against calculating zero uncertainty when a total of zero
counts are observed for the sample and background 3 The formulations for the critical level and minimum detectable concentration are based on the Stapleton
Approximation as recommended in MARLAP Section 20A22 Equations 2054 and 20A32 and Equation 2074
respectively (EPA 2004) The formulations presented here assume an error rate of α = 005 β = 005 (with z1minusα =
z1minusβ = 1645) and d = 04 For methods with very low numbers of counts these expressions provide better estimates
than do the traditional formulas for the critical level and MDC
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 16 Revision 0
aatas
ttt
b
s
b
sbba
b
s
b
s
cIDRVt
IDAt
t
t
ttR
t
t
t
t
L
140645116770140
aatas
ttt
b
ssba
b
s 13291271
MDCIDRVt
IDAt
ttR
t
t
where
Rba = background count rate for the analyte in the defined ROI in counts
per second
122 Results Reporting
1221 The following data should be reported for each result volume of sample
used yield of tracer and its uncertainty and FWHM of each peak used in
the analysis
1222 The following conventions should be used for each result
12221 Result in scientific notation plusmn combined standard uncertainty
13 Method Performance
131 Method validation results performed prior to analyzing samples are to be documented
and reported as required
132 Expected processing time per batch of 10-20 samples plus QC
1321 For an analysis of a 02 L sample aliquant precipitation and preparation of
load solution takes ~1 h
1322 Purification and separation using cartridges and vacuum box system should
take ~2 h
1323 The sample test source preparation step takes ~075 h
1324 A four-hour counting time should be sufficient to meet the MQOs listed in
Step 14 assuming detector efficiency of 015ndash03 and radiochemical yield
of at least 05 A different counting time may be necessary to meet these
MQOs if any of the relevant parameters are significantly different
1325 Data should be ready for reduction ~8-9 h after beginning of analysis
14 Pollution Prevention The method utilizes small volume (2 mL) extraction chromatographic
resin columns This approach leads to a significant reduction in the volumes of load rinse
and strip solutions as compared to classical methods using ion exchange resins to separate
and purify the curium fraction
15 Waste Management
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 17 Revision 0
151 Types of waste generated per sample analyzed
1511 Approximately 210 mL basic waste from the initial sample
preconcentration
1512 Approximately 65 mL of acidic waste from loading and rinsing the two
extraction columns will be generated
1513 Approximately 25 mL of acidic waste from the microprecipitation method
for source preparation will be generated The waste contains 1 mL of HF
and ~ 5 mL of ethanol
1514 TEVAreg
cartridge ndash ready for appropriate disposal
1515 DGA cartridge ndash ready for appropriate disposal
1516 These waste streams may contain low levels of 243
Am (added as tracer) 244
Cm (added to LCS) and other radionuclides as present in samples
152 Evaluate all waste streams according to disposal requirements by applicable
regulations
16 References
Cited References
161 EPA 2009 Method Validation Guide for Radiological Laboratories Participating in
Incident Response Activities Revision 0 Office of Air and Radiation Washington
(MARLAP) 2004 EPA 402-B-1304 04-001A July Volume I Chapters 6 7 20
Glossary Volume II and Volume III Appendix G Available here
163 ASTM D7282 ldquoStandard Practice for Set-up Calibration and Quality Control of
Instruments Used for Radioactivity Measurementsrdquo ASTM Book of Standards 1102
current version ASTM International West Conshohocken PA
164 ASTM D1193 ldquoStandard Specification for Reagent Waterrdquo ASTM Book of Standards
1102 current version ASTM International West Conshohocken PA
Other References
165 EPA 2012 Rapid Radiochemical Method for Americium-241 in Building Materials
for Environmental Remediation Following Radiological Incidents Office of Air and
Radiation Washington DC Available here
166 Maxwell S Culligan B and Noyes G 2010 Rapid Separation Method for Actinides
in Emergency Soil Samples Radiochimica Acta 98(12) 793-800
167 Maxwell S Culligan B Kelsey-Wall A and Shaw P 2011 ldquoRapid Radiochemical
Method for Determination of Actinides in Emergency Concrete and Brick Samplesrdquo
Analytica Chimica Acta 701(1) 112-8
168 VBS01 Rev14 ldquoSetup and Operation Instructions for Eichromrsquos Vacuum Box
System (VBS)rdquo Eichrom Technologies LLC Lisle Illinois (January 2014)
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 18 Revision 0
17 Tables Diagrams Flow Charts and Validation Data
171 Tables
Table 171 Alpha Particle Energies and Abundances of Importance[1]
Nuclide Half-Life
(Years)
λ
(sminus1
) Abundance
α Emission Energy
in kilo electron volts
244Cm
1811 1213times10
minus09
07690 5805
02310 5763
243Cm
291 755times10
minus10
00150 6066
0047 6058
0010968 6010
00568 5992
00069797 5876
0730 5785
0115 5742
0015954 5686
00019942 5682
00013959 5639 244243
Cm (combined) 1811 1213times10
minus09 1000 5805
242Cm
04462 4923times10minus08
02592 6113
07408 6069
245Cm
850times10
3 258times10
minus12
00058 5529
00083 5489
00045 5370
09320 5361
05000 5304
00032 5234
246Cm
476times10
3 461times10
minus12
0822 5387
0178 5344
247Cm
1560times10
7 1408times10
minus15
0138 5267
0057 5212
00120 5147
00200 4985
00160 4943
0710 4870
0047 4820
243Am
7370times10
3 2980times10
minus12
00016 5349
00016 5321
0871 5275
0112 5233
00136 5181 243
Am (combined) 7370times10
3 2980times10
minus12 09998 5275
241Am
4326 5078times10
minus11
00037 5545
000225 5512
0848 5486
0131 5443
001660 5388
[1] Particle energies with abundances less than 01 have been omitted unless they are contiguous with the
radionuclide region of interest
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 19 Revision 0
Data were queried from the NUDAT 2 Decay Radiation database at the Brookhaven National Laboratory National
Nuclear Data Center (httpwwwnndcbnlgovnudat2indx_decjsp) on 9192014
Table 172 Alpha Emissions Sorted by Decreasing Energy
Nuclide Half-Life
(years) λ
(sminus1
) α Emission
Energy (keV)[1]
Abundance 242
Cm 04462 4923times10-08
6113 07408 242
Cm 04462 4923times10-08
6069 02592 243
Cm 291 755times10-10
6066 00150 243
Cm 291 755times10-10
6058 0047 243
Cm 291 755times10-10
6010 0010968 243
Cm 291 755times10-10
5992 00568 243
Cm 291 755times10-10
5876 00069797 244
Cm 1811 1213times10-09
5805 07690 243
Cm 291 755times10-10
5785 0730 244
Cm 1811 1213times10-09
5763 02310 243
Cm 291 755times10-10
5742 0115 243
Cm 291 755times10-10
5686 0015954 243
Cm 291 755times10-10
5682 00019942 243
Cm 291 755times10-10
5639 00013959 241
Am 4326times102 5078times10
-11 5545 00037
245Cm 850times10
3 258times10
-12 5529 00058
241Am 4326times10
2 5078times10
-11 5512 000225
245Cm 850times10
3 258times10
-12 5489 00083
241Am 4326times10
2 5078times10
-11 5486 0848
241Am 4326times10
2 5078times10
-11 5443 0131
241Am 4326times10
2 5078times10
-11 5388 001660
246Cm 476times10
3 461times10
-12 5387 0822
245Cm 850times10
3 258times10
-12 5370 00045
245Cm 850times10
3 258times10
-12 5361 09320
243Am 7370times10
3 2980times10
-12 5349 00016
246Cm 476times10
3 461times10
-12 5344 0178
243Am 7370times10
3 2980times10
-12 5321 00016
245Cm 850times10
3 258times10
-12 5304 05000
243Am 7370times10
3 2980times10
-12 5275 0871
247Cm 1560times10
7 1408times10
-15 5267 0138
245Cm 850times10
3 258times10
-12 5234 00032
243Am 7370times10
3 2980times10
-12 5233 0112
247Cm 1560times10
7 1408times10
-15 5212 0057
247Cm 1560times10
7 1408times10
-15 5147 00120
247Cm 1560times10
7 1408times10
-15 4985 00200
247Cm 1560times10
7 1408times10
-15 4943 00160
247Cm
1560times107 1408times10
-15 4870 0710
247Cm
1560times107 1408times10
-15 4820 0047
[1]Particle energies with abundances less than 01 have been omitted unless they would be contiguous with the
radionuclide region of interest
Data were queried from the NUDAT 2 Decay Radiation database at Brookhaven National Laboratory National
Nuclear Data Center (httpwwwnndcbnlgovnudat2indx_decjsp) on 9192014
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 20 Revision 0
Ingrowth Curves and Ingrowth Factors
This section intentionally left blank
172 Spectrum from a Processed Sample
Curium-244 Spectrum
173 Decay Scheme
244Cm
240Pu
tfrac12=1811 y
tfrac12= 6561times10
3y
α
α
243Am
239Np
tfrac12=7330y
239Pu
tfrac12=619m
β
243Cm
239Pu
tfrac12=291 y
tfrac12= 2411times10
4y
α
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 21 Revision 0
174 Flow Chart
Separation Scheme and Timeline for theDetermination of 244Cm in Water Samples
Aliquant preparation batch
bull Aliquant 200 mL of each sample and QC sample into
centrifuge tubes (11111 - 11114)
bull Acidify with HNO3 to pH lt 2 (11115)
bull Add 244Cm to LCS and 243Am tracer to all samples
(11116- 11117)
Elapsed Time
1 hour
Vacuum box setup
bull Assemble TEVAreg +
DGA cartridges on
vacuum box (11131 -
11135)
bull Condition cartridges with
3M HNO3 and adjust
f low to ~1 mLmin
(11136 - 11138)
Load sample onto TEVAreg amp DGA cartridges
bull Load sample 1 mLmin (11141)
bull Add 5 mL 6M HNO3 tube rinse to column ~2 mLmin (11142)
bull Rinse column with 5 mL 6 MHNO3 ~2 mLmin (11143)
Prepare load solution adjust Pu to Pu4+
bull Dissolve Ca3(PO4)2 with 15 mL HNO3Al(NO3)3 (11121)
bull Add 05 mL 15M sulfamic acid and swirl to mix (11122)
bull Add 125 mL 15M ascorbic acid and swirl to mix and
wait 3 minutes (11123)
bull Add 1 mL 35M sodium nitrite and swirl to mix (11124)
bull Add 15 mL concentrated nitric acid and swirl to mix
(11125)
bull Discard TEVAreg cartridge and load
and rinse solutions (11144)
bull Place f resh reservoirs above each
cartridge (11144)
Continue with Step 11145
frac34 hour
Calcium phosphate preconcentration
bull Add 1 mL 15M Ca(NO3)2 3 mL 32M (NH4)2HPO4
and 2-3 drops phenolphthalein indicator (11118)
bull Add 15M NH4OH to pink phenolphthalein endpoint to
precipitate Ca3(PO4)2 and centrifuge (11119)
bull Decant supernate to waste (111110)
2 hours
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 22 Revision 0
Microprecipitation and sample test source preparation
bull Add 100 microL (50 microg) Ce carrier to each sample (1121)
bull Add 05 mL 30 wt H2O2 (1122)
bull Add 1 mL concentrated HF into each sample (1123)
bull Cap tube mix and wait 15 min (1124)
bull Set up f iltering apparatus (1125 - 1127)
bull Filter sample onto 25-mm 01-microm membrane f ilter (1128)
bull Rinse with ~2-3 mL water and allow to drain (1129)
bull Rinse with ~1-2 mL alcohol to displace water (11210-11211)
bull Mount f ilter for counting (11212)
bull Place f ilter under heat lamp under gentle heat for ~5 min (11213)
Elapsed Time
Cm separation on DGA Resin
bull Rinse column with 20 mL 01M HNO3 ~1-2 mLmin (11145)
bull Rinse column with 15 mL 3M HNO3-025M HF ~1-2 mLmin (11146)
bull Rinse column with 3 mL 4M HCl ~1-2 mLmin remove excess HCl f rom
column (11147)
bull Place f resh connector tips under each column and tubes under each column to
catch Cm (11148)
bull Elute Cm with 10 mL 025M HCl ~1 mLmin (11149)
bull Remove tubes for microprecipitation and continue with Step 112 (111410)
Discard DGA cartridge (111411)
Discard filtrates and rinses (11215)
Continue from Step 11144 2 hours
3 hours
3 frac34 hours
8 hours
Separation Scheme and Timeline for theDetermination of 244Cm in Water Samples (cont)
Count sample test sources (STS)
by alpha spectrometry for 244Cm and 243Am for
four hours or as needed to meet MQOs
(11214)
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 23 Revision 0
Appendix A Composition of Test Samples Used for Validation
Metals by ICP-MS Concentration (μgL) amp Be 0015 (J)
Na 3400
Mg 1500
Al 15 (J)
K 1500
Ca 17000
V 030 (J)
Cr 0075 (J)
Mn 63
Fe 26 (J)
Co 0047 (J)
Ni 069 (J)
Cu 59
Zn 80
As 027 (J)
Se 011 (J)
Mo lt041 (U)
Ag lt00082 (U)
Cd 0010 (J)
Sb 0060 (J)
Ba 20
Tl 0054 (J)
Pb 023 (J)
U 0010 (J)
Radionuclide Activity Concentration (pCiL) 244
Cm 0012 plusmn 0050
252250Cf 0001 plusmn 0044
241Am 020 plusmn 029
232Th
230Th
228Th
0003 plusmn 0034 amp
0052 plusmn 0081 amp
031 plusmn 012 amp
238U
235U
234U
018 plusmn 012 amp
0219 plusmn 0095 amp
0232 plusmn 0096 amp
226Ra 0049 plusmn 0024
amp
Qualifiers (U) ndash Result is less than the Instrument Detection Limit (IDL) per
SW846 Method 6020A
(J) ndash Result falls between the IDL and the reporting limit amp Mean plusmn 2 standard deviations of triplicate analyses of each of two Montgomery
Alabama tap water Mean plusmn 2 standard deviations of replicate analysis of seven samples of
Montgomery Alabama tap water
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 13 Revision 0
11213 Place the filter under a heat lamp for approximately 5 minutes or longer
until it is completely dry
11214 Count filters for an appropriate period of time by alpha spectrometry
11215 Discard the filtrate to waste for future disposal If the filtrate is to be
retained it should be stored in a plastic container since glass will be
attacked by HF
NOTE Other methods for STS preparation such as electrodeposition or
microprecipitation with neodymium fluoride may be used in lieu of the cerium
fluoride microprecipitation but any such substitution must be validated as described
in Step 15
12 Data Analysis and Calculations
121 Equations for activity concentration combined standard uncertainty and
radiochemical yield (if required)
1211 The activity concentration of the analyte and its combined standard
uncertainty are calculated using the following equations
aata
ttata
IDRV
IDRAAC
2
t
t
2
2
a
a
2
2
t
t
22
a2
a
2
a
2
t
2
a
2
t
2
t
2
ta
2
ac
)()()()()(
R
Ru
V
Vu
A
AuAC
IDRV
IDARuACu
ttt
tD
e
aat
aD
e
Where
ACa = activity concentration of the analyte at time of collection (or other
specified reference time) in picocuries per liter (pCiL)
At = activity of the tracer added to the sample aliquant on the tracer
solution reference datetime (pCi)
Ra = net count rate of the analyte in the defined region of interest (ROI)
in counts per second (see 1212)
Rt = net count rate of the tracer in the defined ROI in counts per second
(see 1212)
Va = volume of the sample aliquant (L)
Dt = correction factor for decay of the tracer from its reference date and
time to the midpoint of the counting period
Da = correction factor for decay of the analyte from the time of sample
collection (or other reference time) to the midpoint of the counting
period
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 14 Revision 0
It = probability of α emission in the defined ROI per decay of the tracer
(Table 171)
Ia = probability of α emission in the defined ROI per decay of the analyte
(Table 171)
uc(ACa) = combined standard uncertainty of the activity concentration of the
analyte (pCiL)
u(At) = standard uncertainty of the activity of the tracer added to the sample
(pCi)
u(Ra) = standard uncertainty of the net count rate of the analyte (sminus1
) (see
1212)
u(Rt) = standard uncertainty of the net count rate of the tracer (sminus1
) (see
1212)
u(Va) = standard uncertainty of the size of the sample aliquant volume (L)
λt = decay constant for the tracer radionuclide (sminus1
see Table 171)
λa = decay constant for the analyte radionuclide (sminus1
see Table 171)
tt = time elapsed between the activity reference date for the tracer and
the midpoint of the sample count (s)
ta = time elapsed between the activity reference date for the sample (eg
collection date) and the midpoint of the sample count (s)
NOTE The uncertainties of the decay-correction factors and of the probability of decay
factors are assumed to be negligible
NOTE The equation for the combined standard uncertainty (uc(ACa)) calculation is arranged to
eliminate the possibility of dividing by zero if Ra = 0
NOTE The standard uncertainty of the activity of the tracer added to the sample must reflect the
uncertainty associated with the activity of the standard reference material and any other
significant sources of uncertainty such as those introduced during the preparation of the tracer
solution (eg weighing or dilution factors) and during the process of adding the tracer to the
sample
1212 The net count rate of an analyte or tracer and its standard uncertainty are
calculated using the following equations
b
bx
s
xx
t
C
t
CR
and
2
b
bx
2
s
xx
11)(
t
C
t
CRu
where
Rx = net count rate of analyte or tracer in counts per second
Cx = sample counts in the analyte or the tracer ROI
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 15 Revision 0
ts = sample count time (s)
Cbx = background counts in the same ROI as for x
tb = background count time (s)
u(Rx) = standard uncertainty of the net count rate of tracer or analyte in
counts per second2
If the radiochemical yield of the tracer is requested the yield and its combined
standard uncertainty can be calculated using the following equations
ttt
t
0370 IDA
RRY
and
2
2
2
t
t
2
2
t
t
2)()()(
)(
u
A
Au
R
RuRYRYuc
where
RY = radiochemical yield of the tracer expressed as a fraction
Rt = net count rate of the tracer in counts per second
At = activity of the tracer added to the sample (pCi)
Dt = correction factor for decay of the tracer from its reference date and
time to the midpoint of the counting period
It = probability of α emission in the defined ROI per decay of the tracer
(Table 171)
ε = detector efficiency expressed as a fraction
uc(RY) = combined standard uncertainty of the radiochemical yield
u(Rt) = standard uncertainty of the net count rate of the tracer in counts per
second
u(At) = standard uncertainty of the activity of the tracer added to the sample
(pCi)
u(ε) = standard uncertainty of the detector efficiency
1213 If the critical level concentration (Lc) or the minimum detectable
concentration (MDC) are requested (at an error rate of 5) they can be
calculated using the following equations 3
2 For methods with very low counts MARLAP Section 19522 recommends adding one count each to the gross
counts and the background counts when estimating the uncertainty of the respective net counts This minimizes
negative bias in the estimate of uncertainty and protects against calculating zero uncertainty when a total of zero
counts are observed for the sample and background 3 The formulations for the critical level and minimum detectable concentration are based on the Stapleton
Approximation as recommended in MARLAP Section 20A22 Equations 2054 and 20A32 and Equation 2074
respectively (EPA 2004) The formulations presented here assume an error rate of α = 005 β = 005 (with z1minusα =
z1minusβ = 1645) and d = 04 For methods with very low numbers of counts these expressions provide better estimates
than do the traditional formulas for the critical level and MDC
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 16 Revision 0
aatas
ttt
b
s
b
sbba
b
s
b
s
cIDRVt
IDAt
t
t
ttR
t
t
t
t
L
140645116770140
aatas
ttt
b
ssba
b
s 13291271
MDCIDRVt
IDAt
ttR
t
t
where
Rba = background count rate for the analyte in the defined ROI in counts
per second
122 Results Reporting
1221 The following data should be reported for each result volume of sample
used yield of tracer and its uncertainty and FWHM of each peak used in
the analysis
1222 The following conventions should be used for each result
12221 Result in scientific notation plusmn combined standard uncertainty
13 Method Performance
131 Method validation results performed prior to analyzing samples are to be documented
and reported as required
132 Expected processing time per batch of 10-20 samples plus QC
1321 For an analysis of a 02 L sample aliquant precipitation and preparation of
load solution takes ~1 h
1322 Purification and separation using cartridges and vacuum box system should
take ~2 h
1323 The sample test source preparation step takes ~075 h
1324 A four-hour counting time should be sufficient to meet the MQOs listed in
Step 14 assuming detector efficiency of 015ndash03 and radiochemical yield
of at least 05 A different counting time may be necessary to meet these
MQOs if any of the relevant parameters are significantly different
1325 Data should be ready for reduction ~8-9 h after beginning of analysis
14 Pollution Prevention The method utilizes small volume (2 mL) extraction chromatographic
resin columns This approach leads to a significant reduction in the volumes of load rinse
and strip solutions as compared to classical methods using ion exchange resins to separate
and purify the curium fraction
15 Waste Management
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 17 Revision 0
151 Types of waste generated per sample analyzed
1511 Approximately 210 mL basic waste from the initial sample
preconcentration
1512 Approximately 65 mL of acidic waste from loading and rinsing the two
extraction columns will be generated
1513 Approximately 25 mL of acidic waste from the microprecipitation method
for source preparation will be generated The waste contains 1 mL of HF
and ~ 5 mL of ethanol
1514 TEVAreg
cartridge ndash ready for appropriate disposal
1515 DGA cartridge ndash ready for appropriate disposal
1516 These waste streams may contain low levels of 243
Am (added as tracer) 244
Cm (added to LCS) and other radionuclides as present in samples
152 Evaluate all waste streams according to disposal requirements by applicable
regulations
16 References
Cited References
161 EPA 2009 Method Validation Guide for Radiological Laboratories Participating in
Incident Response Activities Revision 0 Office of Air and Radiation Washington
(MARLAP) 2004 EPA 402-B-1304 04-001A July Volume I Chapters 6 7 20
Glossary Volume II and Volume III Appendix G Available here
163 ASTM D7282 ldquoStandard Practice for Set-up Calibration and Quality Control of
Instruments Used for Radioactivity Measurementsrdquo ASTM Book of Standards 1102
current version ASTM International West Conshohocken PA
164 ASTM D1193 ldquoStandard Specification for Reagent Waterrdquo ASTM Book of Standards
1102 current version ASTM International West Conshohocken PA
Other References
165 EPA 2012 Rapid Radiochemical Method for Americium-241 in Building Materials
for Environmental Remediation Following Radiological Incidents Office of Air and
Radiation Washington DC Available here
166 Maxwell S Culligan B and Noyes G 2010 Rapid Separation Method for Actinides
in Emergency Soil Samples Radiochimica Acta 98(12) 793-800
167 Maxwell S Culligan B Kelsey-Wall A and Shaw P 2011 ldquoRapid Radiochemical
Method for Determination of Actinides in Emergency Concrete and Brick Samplesrdquo
Analytica Chimica Acta 701(1) 112-8
168 VBS01 Rev14 ldquoSetup and Operation Instructions for Eichromrsquos Vacuum Box
System (VBS)rdquo Eichrom Technologies LLC Lisle Illinois (January 2014)
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 18 Revision 0
17 Tables Diagrams Flow Charts and Validation Data
171 Tables
Table 171 Alpha Particle Energies and Abundances of Importance[1]
Nuclide Half-Life
(Years)
λ
(sminus1
) Abundance
α Emission Energy
in kilo electron volts
244Cm
1811 1213times10
minus09
07690 5805
02310 5763
243Cm
291 755times10
minus10
00150 6066
0047 6058
0010968 6010
00568 5992
00069797 5876
0730 5785
0115 5742
0015954 5686
00019942 5682
00013959 5639 244243
Cm (combined) 1811 1213times10
minus09 1000 5805
242Cm
04462 4923times10minus08
02592 6113
07408 6069
245Cm
850times10
3 258times10
minus12
00058 5529
00083 5489
00045 5370
09320 5361
05000 5304
00032 5234
246Cm
476times10
3 461times10
minus12
0822 5387
0178 5344
247Cm
1560times10
7 1408times10
minus15
0138 5267
0057 5212
00120 5147
00200 4985
00160 4943
0710 4870
0047 4820
243Am
7370times10
3 2980times10
minus12
00016 5349
00016 5321
0871 5275
0112 5233
00136 5181 243
Am (combined) 7370times10
3 2980times10
minus12 09998 5275
241Am
4326 5078times10
minus11
00037 5545
000225 5512
0848 5486
0131 5443
001660 5388
[1] Particle energies with abundances less than 01 have been omitted unless they are contiguous with the
radionuclide region of interest
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 19 Revision 0
Data were queried from the NUDAT 2 Decay Radiation database at the Brookhaven National Laboratory National
Nuclear Data Center (httpwwwnndcbnlgovnudat2indx_decjsp) on 9192014
Table 172 Alpha Emissions Sorted by Decreasing Energy
Nuclide Half-Life
(years) λ
(sminus1
) α Emission
Energy (keV)[1]
Abundance 242
Cm 04462 4923times10-08
6113 07408 242
Cm 04462 4923times10-08
6069 02592 243
Cm 291 755times10-10
6066 00150 243
Cm 291 755times10-10
6058 0047 243
Cm 291 755times10-10
6010 0010968 243
Cm 291 755times10-10
5992 00568 243
Cm 291 755times10-10
5876 00069797 244
Cm 1811 1213times10-09
5805 07690 243
Cm 291 755times10-10
5785 0730 244
Cm 1811 1213times10-09
5763 02310 243
Cm 291 755times10-10
5742 0115 243
Cm 291 755times10-10
5686 0015954 243
Cm 291 755times10-10
5682 00019942 243
Cm 291 755times10-10
5639 00013959 241
Am 4326times102 5078times10
-11 5545 00037
245Cm 850times10
3 258times10
-12 5529 00058
241Am 4326times10
2 5078times10
-11 5512 000225
245Cm 850times10
3 258times10
-12 5489 00083
241Am 4326times10
2 5078times10
-11 5486 0848
241Am 4326times10
2 5078times10
-11 5443 0131
241Am 4326times10
2 5078times10
-11 5388 001660
246Cm 476times10
3 461times10
-12 5387 0822
245Cm 850times10
3 258times10
-12 5370 00045
245Cm 850times10
3 258times10
-12 5361 09320
243Am 7370times10
3 2980times10
-12 5349 00016
246Cm 476times10
3 461times10
-12 5344 0178
243Am 7370times10
3 2980times10
-12 5321 00016
245Cm 850times10
3 258times10
-12 5304 05000
243Am 7370times10
3 2980times10
-12 5275 0871
247Cm 1560times10
7 1408times10
-15 5267 0138
245Cm 850times10
3 258times10
-12 5234 00032
243Am 7370times10
3 2980times10
-12 5233 0112
247Cm 1560times10
7 1408times10
-15 5212 0057
247Cm 1560times10
7 1408times10
-15 5147 00120
247Cm 1560times10
7 1408times10
-15 4985 00200
247Cm 1560times10
7 1408times10
-15 4943 00160
247Cm
1560times107 1408times10
-15 4870 0710
247Cm
1560times107 1408times10
-15 4820 0047
[1]Particle energies with abundances less than 01 have been omitted unless they would be contiguous with the
radionuclide region of interest
Data were queried from the NUDAT 2 Decay Radiation database at Brookhaven National Laboratory National
Nuclear Data Center (httpwwwnndcbnlgovnudat2indx_decjsp) on 9192014
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 20 Revision 0
Ingrowth Curves and Ingrowth Factors
This section intentionally left blank
172 Spectrum from a Processed Sample
Curium-244 Spectrum
173 Decay Scheme
244Cm
240Pu
tfrac12=1811 y
tfrac12= 6561times10
3y
α
α
243Am
239Np
tfrac12=7330y
239Pu
tfrac12=619m
β
243Cm
239Pu
tfrac12=291 y
tfrac12= 2411times10
4y
α
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 21 Revision 0
174 Flow Chart
Separation Scheme and Timeline for theDetermination of 244Cm in Water Samples
Aliquant preparation batch
bull Aliquant 200 mL of each sample and QC sample into
centrifuge tubes (11111 - 11114)
bull Acidify with HNO3 to pH lt 2 (11115)
bull Add 244Cm to LCS and 243Am tracer to all samples
(11116- 11117)
Elapsed Time
1 hour
Vacuum box setup
bull Assemble TEVAreg +
DGA cartridges on
vacuum box (11131 -
11135)
bull Condition cartridges with
3M HNO3 and adjust
f low to ~1 mLmin
(11136 - 11138)
Load sample onto TEVAreg amp DGA cartridges
bull Load sample 1 mLmin (11141)
bull Add 5 mL 6M HNO3 tube rinse to column ~2 mLmin (11142)
bull Rinse column with 5 mL 6 MHNO3 ~2 mLmin (11143)
Prepare load solution adjust Pu to Pu4+
bull Dissolve Ca3(PO4)2 with 15 mL HNO3Al(NO3)3 (11121)
bull Add 05 mL 15M sulfamic acid and swirl to mix (11122)
bull Add 125 mL 15M ascorbic acid and swirl to mix and
wait 3 minutes (11123)
bull Add 1 mL 35M sodium nitrite and swirl to mix (11124)
bull Add 15 mL concentrated nitric acid and swirl to mix
(11125)
bull Discard TEVAreg cartridge and load
and rinse solutions (11144)
bull Place f resh reservoirs above each
cartridge (11144)
Continue with Step 11145
frac34 hour
Calcium phosphate preconcentration
bull Add 1 mL 15M Ca(NO3)2 3 mL 32M (NH4)2HPO4
and 2-3 drops phenolphthalein indicator (11118)
bull Add 15M NH4OH to pink phenolphthalein endpoint to
precipitate Ca3(PO4)2 and centrifuge (11119)
bull Decant supernate to waste (111110)
2 hours
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 22 Revision 0
Microprecipitation and sample test source preparation
bull Add 100 microL (50 microg) Ce carrier to each sample (1121)
bull Add 05 mL 30 wt H2O2 (1122)
bull Add 1 mL concentrated HF into each sample (1123)
bull Cap tube mix and wait 15 min (1124)
bull Set up f iltering apparatus (1125 - 1127)
bull Filter sample onto 25-mm 01-microm membrane f ilter (1128)
bull Rinse with ~2-3 mL water and allow to drain (1129)
bull Rinse with ~1-2 mL alcohol to displace water (11210-11211)
bull Mount f ilter for counting (11212)
bull Place f ilter under heat lamp under gentle heat for ~5 min (11213)
Elapsed Time
Cm separation on DGA Resin
bull Rinse column with 20 mL 01M HNO3 ~1-2 mLmin (11145)
bull Rinse column with 15 mL 3M HNO3-025M HF ~1-2 mLmin (11146)
bull Rinse column with 3 mL 4M HCl ~1-2 mLmin remove excess HCl f rom
column (11147)
bull Place f resh connector tips under each column and tubes under each column to
catch Cm (11148)
bull Elute Cm with 10 mL 025M HCl ~1 mLmin (11149)
bull Remove tubes for microprecipitation and continue with Step 112 (111410)
Discard DGA cartridge (111411)
Discard filtrates and rinses (11215)
Continue from Step 11144 2 hours
3 hours
3 frac34 hours
8 hours
Separation Scheme and Timeline for theDetermination of 244Cm in Water Samples (cont)
Count sample test sources (STS)
by alpha spectrometry for 244Cm and 243Am for
four hours or as needed to meet MQOs
(11214)
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 23 Revision 0
Appendix A Composition of Test Samples Used for Validation
Metals by ICP-MS Concentration (μgL) amp Be 0015 (J)
Na 3400
Mg 1500
Al 15 (J)
K 1500
Ca 17000
V 030 (J)
Cr 0075 (J)
Mn 63
Fe 26 (J)
Co 0047 (J)
Ni 069 (J)
Cu 59
Zn 80
As 027 (J)
Se 011 (J)
Mo lt041 (U)
Ag lt00082 (U)
Cd 0010 (J)
Sb 0060 (J)
Ba 20
Tl 0054 (J)
Pb 023 (J)
U 0010 (J)
Radionuclide Activity Concentration (pCiL) 244
Cm 0012 plusmn 0050
252250Cf 0001 plusmn 0044
241Am 020 plusmn 029
232Th
230Th
228Th
0003 plusmn 0034 amp
0052 plusmn 0081 amp
031 plusmn 012 amp
238U
235U
234U
018 plusmn 012 amp
0219 plusmn 0095 amp
0232 plusmn 0096 amp
226Ra 0049 plusmn 0024
amp
Qualifiers (U) ndash Result is less than the Instrument Detection Limit (IDL) per
SW846 Method 6020A
(J) ndash Result falls between the IDL and the reporting limit amp Mean plusmn 2 standard deviations of triplicate analyses of each of two Montgomery
Alabama tap water Mean plusmn 2 standard deviations of replicate analysis of seven samples of
Montgomery Alabama tap water
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 14 Revision 0
It = probability of α emission in the defined ROI per decay of the tracer
(Table 171)
Ia = probability of α emission in the defined ROI per decay of the analyte
(Table 171)
uc(ACa) = combined standard uncertainty of the activity concentration of the
analyte (pCiL)
u(At) = standard uncertainty of the activity of the tracer added to the sample
(pCi)
u(Ra) = standard uncertainty of the net count rate of the analyte (sminus1
) (see
1212)
u(Rt) = standard uncertainty of the net count rate of the tracer (sminus1
) (see
1212)
u(Va) = standard uncertainty of the size of the sample aliquant volume (L)
λt = decay constant for the tracer radionuclide (sminus1
see Table 171)
λa = decay constant for the analyte radionuclide (sminus1
see Table 171)
tt = time elapsed between the activity reference date for the tracer and
the midpoint of the sample count (s)
ta = time elapsed between the activity reference date for the sample (eg
collection date) and the midpoint of the sample count (s)
NOTE The uncertainties of the decay-correction factors and of the probability of decay
factors are assumed to be negligible
NOTE The equation for the combined standard uncertainty (uc(ACa)) calculation is arranged to
eliminate the possibility of dividing by zero if Ra = 0
NOTE The standard uncertainty of the activity of the tracer added to the sample must reflect the
uncertainty associated with the activity of the standard reference material and any other
significant sources of uncertainty such as those introduced during the preparation of the tracer
solution (eg weighing or dilution factors) and during the process of adding the tracer to the
sample
1212 The net count rate of an analyte or tracer and its standard uncertainty are
calculated using the following equations
b
bx
s
xx
t
C
t
CR
and
2
b
bx
2
s
xx
11)(
t
C
t
CRu
where
Rx = net count rate of analyte or tracer in counts per second
Cx = sample counts in the analyte or the tracer ROI
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 15 Revision 0
ts = sample count time (s)
Cbx = background counts in the same ROI as for x
tb = background count time (s)
u(Rx) = standard uncertainty of the net count rate of tracer or analyte in
counts per second2
If the radiochemical yield of the tracer is requested the yield and its combined
standard uncertainty can be calculated using the following equations
ttt
t
0370 IDA
RRY
and
2
2
2
t
t
2
2
t
t
2)()()(
)(
u
A
Au
R
RuRYRYuc
where
RY = radiochemical yield of the tracer expressed as a fraction
Rt = net count rate of the tracer in counts per second
At = activity of the tracer added to the sample (pCi)
Dt = correction factor for decay of the tracer from its reference date and
time to the midpoint of the counting period
It = probability of α emission in the defined ROI per decay of the tracer
(Table 171)
ε = detector efficiency expressed as a fraction
uc(RY) = combined standard uncertainty of the radiochemical yield
u(Rt) = standard uncertainty of the net count rate of the tracer in counts per
second
u(At) = standard uncertainty of the activity of the tracer added to the sample
(pCi)
u(ε) = standard uncertainty of the detector efficiency
1213 If the critical level concentration (Lc) or the minimum detectable
concentration (MDC) are requested (at an error rate of 5) they can be
calculated using the following equations 3
2 For methods with very low counts MARLAP Section 19522 recommends adding one count each to the gross
counts and the background counts when estimating the uncertainty of the respective net counts This minimizes
negative bias in the estimate of uncertainty and protects against calculating zero uncertainty when a total of zero
counts are observed for the sample and background 3 The formulations for the critical level and minimum detectable concentration are based on the Stapleton
Approximation as recommended in MARLAP Section 20A22 Equations 2054 and 20A32 and Equation 2074
respectively (EPA 2004) The formulations presented here assume an error rate of α = 005 β = 005 (with z1minusα =
z1minusβ = 1645) and d = 04 For methods with very low numbers of counts these expressions provide better estimates
than do the traditional formulas for the critical level and MDC
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 16 Revision 0
aatas
ttt
b
s
b
sbba
b
s
b
s
cIDRVt
IDAt
t
t
ttR
t
t
t
t
L
140645116770140
aatas
ttt
b
ssba
b
s 13291271
MDCIDRVt
IDAt
ttR
t
t
where
Rba = background count rate for the analyte in the defined ROI in counts
per second
122 Results Reporting
1221 The following data should be reported for each result volume of sample
used yield of tracer and its uncertainty and FWHM of each peak used in
the analysis
1222 The following conventions should be used for each result
12221 Result in scientific notation plusmn combined standard uncertainty
13 Method Performance
131 Method validation results performed prior to analyzing samples are to be documented
and reported as required
132 Expected processing time per batch of 10-20 samples plus QC
1321 For an analysis of a 02 L sample aliquant precipitation and preparation of
load solution takes ~1 h
1322 Purification and separation using cartridges and vacuum box system should
take ~2 h
1323 The sample test source preparation step takes ~075 h
1324 A four-hour counting time should be sufficient to meet the MQOs listed in
Step 14 assuming detector efficiency of 015ndash03 and radiochemical yield
of at least 05 A different counting time may be necessary to meet these
MQOs if any of the relevant parameters are significantly different
1325 Data should be ready for reduction ~8-9 h after beginning of analysis
14 Pollution Prevention The method utilizes small volume (2 mL) extraction chromatographic
resin columns This approach leads to a significant reduction in the volumes of load rinse
and strip solutions as compared to classical methods using ion exchange resins to separate
and purify the curium fraction
15 Waste Management
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 17 Revision 0
151 Types of waste generated per sample analyzed
1511 Approximately 210 mL basic waste from the initial sample
preconcentration
1512 Approximately 65 mL of acidic waste from loading and rinsing the two
extraction columns will be generated
1513 Approximately 25 mL of acidic waste from the microprecipitation method
for source preparation will be generated The waste contains 1 mL of HF
and ~ 5 mL of ethanol
1514 TEVAreg
cartridge ndash ready for appropriate disposal
1515 DGA cartridge ndash ready for appropriate disposal
1516 These waste streams may contain low levels of 243
Am (added as tracer) 244
Cm (added to LCS) and other radionuclides as present in samples
152 Evaluate all waste streams according to disposal requirements by applicable
regulations
16 References
Cited References
161 EPA 2009 Method Validation Guide for Radiological Laboratories Participating in
Incident Response Activities Revision 0 Office of Air and Radiation Washington
(MARLAP) 2004 EPA 402-B-1304 04-001A July Volume I Chapters 6 7 20
Glossary Volume II and Volume III Appendix G Available here
163 ASTM D7282 ldquoStandard Practice for Set-up Calibration and Quality Control of
Instruments Used for Radioactivity Measurementsrdquo ASTM Book of Standards 1102
current version ASTM International West Conshohocken PA
164 ASTM D1193 ldquoStandard Specification for Reagent Waterrdquo ASTM Book of Standards
1102 current version ASTM International West Conshohocken PA
Other References
165 EPA 2012 Rapid Radiochemical Method for Americium-241 in Building Materials
for Environmental Remediation Following Radiological Incidents Office of Air and
Radiation Washington DC Available here
166 Maxwell S Culligan B and Noyes G 2010 Rapid Separation Method for Actinides
in Emergency Soil Samples Radiochimica Acta 98(12) 793-800
167 Maxwell S Culligan B Kelsey-Wall A and Shaw P 2011 ldquoRapid Radiochemical
Method for Determination of Actinides in Emergency Concrete and Brick Samplesrdquo
Analytica Chimica Acta 701(1) 112-8
168 VBS01 Rev14 ldquoSetup and Operation Instructions for Eichromrsquos Vacuum Box
System (VBS)rdquo Eichrom Technologies LLC Lisle Illinois (January 2014)
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 18 Revision 0
17 Tables Diagrams Flow Charts and Validation Data
171 Tables
Table 171 Alpha Particle Energies and Abundances of Importance[1]
Nuclide Half-Life
(Years)
λ
(sminus1
) Abundance
α Emission Energy
in kilo electron volts
244Cm
1811 1213times10
minus09
07690 5805
02310 5763
243Cm
291 755times10
minus10
00150 6066
0047 6058
0010968 6010
00568 5992
00069797 5876
0730 5785
0115 5742
0015954 5686
00019942 5682
00013959 5639 244243
Cm (combined) 1811 1213times10
minus09 1000 5805
242Cm
04462 4923times10minus08
02592 6113
07408 6069
245Cm
850times10
3 258times10
minus12
00058 5529
00083 5489
00045 5370
09320 5361
05000 5304
00032 5234
246Cm
476times10
3 461times10
minus12
0822 5387
0178 5344
247Cm
1560times10
7 1408times10
minus15
0138 5267
0057 5212
00120 5147
00200 4985
00160 4943
0710 4870
0047 4820
243Am
7370times10
3 2980times10
minus12
00016 5349
00016 5321
0871 5275
0112 5233
00136 5181 243
Am (combined) 7370times10
3 2980times10
minus12 09998 5275
241Am
4326 5078times10
minus11
00037 5545
000225 5512
0848 5486
0131 5443
001660 5388
[1] Particle energies with abundances less than 01 have been omitted unless they are contiguous with the
radionuclide region of interest
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 19 Revision 0
Data were queried from the NUDAT 2 Decay Radiation database at the Brookhaven National Laboratory National
Nuclear Data Center (httpwwwnndcbnlgovnudat2indx_decjsp) on 9192014
Table 172 Alpha Emissions Sorted by Decreasing Energy
Nuclide Half-Life
(years) λ
(sminus1
) α Emission
Energy (keV)[1]
Abundance 242
Cm 04462 4923times10-08
6113 07408 242
Cm 04462 4923times10-08
6069 02592 243
Cm 291 755times10-10
6066 00150 243
Cm 291 755times10-10
6058 0047 243
Cm 291 755times10-10
6010 0010968 243
Cm 291 755times10-10
5992 00568 243
Cm 291 755times10-10
5876 00069797 244
Cm 1811 1213times10-09
5805 07690 243
Cm 291 755times10-10
5785 0730 244
Cm 1811 1213times10-09
5763 02310 243
Cm 291 755times10-10
5742 0115 243
Cm 291 755times10-10
5686 0015954 243
Cm 291 755times10-10
5682 00019942 243
Cm 291 755times10-10
5639 00013959 241
Am 4326times102 5078times10
-11 5545 00037
245Cm 850times10
3 258times10
-12 5529 00058
241Am 4326times10
2 5078times10
-11 5512 000225
245Cm 850times10
3 258times10
-12 5489 00083
241Am 4326times10
2 5078times10
-11 5486 0848
241Am 4326times10
2 5078times10
-11 5443 0131
241Am 4326times10
2 5078times10
-11 5388 001660
246Cm 476times10
3 461times10
-12 5387 0822
245Cm 850times10
3 258times10
-12 5370 00045
245Cm 850times10
3 258times10
-12 5361 09320
243Am 7370times10
3 2980times10
-12 5349 00016
246Cm 476times10
3 461times10
-12 5344 0178
243Am 7370times10
3 2980times10
-12 5321 00016
245Cm 850times10
3 258times10
-12 5304 05000
243Am 7370times10
3 2980times10
-12 5275 0871
247Cm 1560times10
7 1408times10
-15 5267 0138
245Cm 850times10
3 258times10
-12 5234 00032
243Am 7370times10
3 2980times10
-12 5233 0112
247Cm 1560times10
7 1408times10
-15 5212 0057
247Cm 1560times10
7 1408times10
-15 5147 00120
247Cm 1560times10
7 1408times10
-15 4985 00200
247Cm 1560times10
7 1408times10
-15 4943 00160
247Cm
1560times107 1408times10
-15 4870 0710
247Cm
1560times107 1408times10
-15 4820 0047
[1]Particle energies with abundances less than 01 have been omitted unless they would be contiguous with the
radionuclide region of interest
Data were queried from the NUDAT 2 Decay Radiation database at Brookhaven National Laboratory National
Nuclear Data Center (httpwwwnndcbnlgovnudat2indx_decjsp) on 9192014
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 20 Revision 0
Ingrowth Curves and Ingrowth Factors
This section intentionally left blank
172 Spectrum from a Processed Sample
Curium-244 Spectrum
173 Decay Scheme
244Cm
240Pu
tfrac12=1811 y
tfrac12= 6561times10
3y
α
α
243Am
239Np
tfrac12=7330y
239Pu
tfrac12=619m
β
243Cm
239Pu
tfrac12=291 y
tfrac12= 2411times10
4y
α
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 21 Revision 0
174 Flow Chart
Separation Scheme and Timeline for theDetermination of 244Cm in Water Samples
Aliquant preparation batch
bull Aliquant 200 mL of each sample and QC sample into
centrifuge tubes (11111 - 11114)
bull Acidify with HNO3 to pH lt 2 (11115)
bull Add 244Cm to LCS and 243Am tracer to all samples
(11116- 11117)
Elapsed Time
1 hour
Vacuum box setup
bull Assemble TEVAreg +
DGA cartridges on
vacuum box (11131 -
11135)
bull Condition cartridges with
3M HNO3 and adjust
f low to ~1 mLmin
(11136 - 11138)
Load sample onto TEVAreg amp DGA cartridges
bull Load sample 1 mLmin (11141)
bull Add 5 mL 6M HNO3 tube rinse to column ~2 mLmin (11142)
bull Rinse column with 5 mL 6 MHNO3 ~2 mLmin (11143)
Prepare load solution adjust Pu to Pu4+
bull Dissolve Ca3(PO4)2 with 15 mL HNO3Al(NO3)3 (11121)
bull Add 05 mL 15M sulfamic acid and swirl to mix (11122)
bull Add 125 mL 15M ascorbic acid and swirl to mix and
wait 3 minutes (11123)
bull Add 1 mL 35M sodium nitrite and swirl to mix (11124)
bull Add 15 mL concentrated nitric acid and swirl to mix
(11125)
bull Discard TEVAreg cartridge and load
and rinse solutions (11144)
bull Place f resh reservoirs above each
cartridge (11144)
Continue with Step 11145
frac34 hour
Calcium phosphate preconcentration
bull Add 1 mL 15M Ca(NO3)2 3 mL 32M (NH4)2HPO4
and 2-3 drops phenolphthalein indicator (11118)
bull Add 15M NH4OH to pink phenolphthalein endpoint to
precipitate Ca3(PO4)2 and centrifuge (11119)
bull Decant supernate to waste (111110)
2 hours
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 22 Revision 0
Microprecipitation and sample test source preparation
bull Add 100 microL (50 microg) Ce carrier to each sample (1121)
bull Add 05 mL 30 wt H2O2 (1122)
bull Add 1 mL concentrated HF into each sample (1123)
bull Cap tube mix and wait 15 min (1124)
bull Set up f iltering apparatus (1125 - 1127)
bull Filter sample onto 25-mm 01-microm membrane f ilter (1128)
bull Rinse with ~2-3 mL water and allow to drain (1129)
bull Rinse with ~1-2 mL alcohol to displace water (11210-11211)
bull Mount f ilter for counting (11212)
bull Place f ilter under heat lamp under gentle heat for ~5 min (11213)
Elapsed Time
Cm separation on DGA Resin
bull Rinse column with 20 mL 01M HNO3 ~1-2 mLmin (11145)
bull Rinse column with 15 mL 3M HNO3-025M HF ~1-2 mLmin (11146)
bull Rinse column with 3 mL 4M HCl ~1-2 mLmin remove excess HCl f rom
column (11147)
bull Place f resh connector tips under each column and tubes under each column to
catch Cm (11148)
bull Elute Cm with 10 mL 025M HCl ~1 mLmin (11149)
bull Remove tubes for microprecipitation and continue with Step 112 (111410)
Discard DGA cartridge (111411)
Discard filtrates and rinses (11215)
Continue from Step 11144 2 hours
3 hours
3 frac34 hours
8 hours
Separation Scheme and Timeline for theDetermination of 244Cm in Water Samples (cont)
Count sample test sources (STS)
by alpha spectrometry for 244Cm and 243Am for
four hours or as needed to meet MQOs
(11214)
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 23 Revision 0
Appendix A Composition of Test Samples Used for Validation
Metals by ICP-MS Concentration (μgL) amp Be 0015 (J)
Na 3400
Mg 1500
Al 15 (J)
K 1500
Ca 17000
V 030 (J)
Cr 0075 (J)
Mn 63
Fe 26 (J)
Co 0047 (J)
Ni 069 (J)
Cu 59
Zn 80
As 027 (J)
Se 011 (J)
Mo lt041 (U)
Ag lt00082 (U)
Cd 0010 (J)
Sb 0060 (J)
Ba 20
Tl 0054 (J)
Pb 023 (J)
U 0010 (J)
Radionuclide Activity Concentration (pCiL) 244
Cm 0012 plusmn 0050
252250Cf 0001 plusmn 0044
241Am 020 plusmn 029
232Th
230Th
228Th
0003 plusmn 0034 amp
0052 plusmn 0081 amp
031 plusmn 012 amp
238U
235U
234U
018 plusmn 012 amp
0219 plusmn 0095 amp
0232 plusmn 0096 amp
226Ra 0049 plusmn 0024
amp
Qualifiers (U) ndash Result is less than the Instrument Detection Limit (IDL) per
SW846 Method 6020A
(J) ndash Result falls between the IDL and the reporting limit amp Mean plusmn 2 standard deviations of triplicate analyses of each of two Montgomery
Alabama tap water Mean plusmn 2 standard deviations of replicate analysis of seven samples of
Montgomery Alabama tap water
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 15 Revision 0
ts = sample count time (s)
Cbx = background counts in the same ROI as for x
tb = background count time (s)
u(Rx) = standard uncertainty of the net count rate of tracer or analyte in
counts per second2
If the radiochemical yield of the tracer is requested the yield and its combined
standard uncertainty can be calculated using the following equations
ttt
t
0370 IDA
RRY
and
2
2
2
t
t
2
2
t
t
2)()()(
)(
u
A
Au
R
RuRYRYuc
where
RY = radiochemical yield of the tracer expressed as a fraction
Rt = net count rate of the tracer in counts per second
At = activity of the tracer added to the sample (pCi)
Dt = correction factor for decay of the tracer from its reference date and
time to the midpoint of the counting period
It = probability of α emission in the defined ROI per decay of the tracer
(Table 171)
ε = detector efficiency expressed as a fraction
uc(RY) = combined standard uncertainty of the radiochemical yield
u(Rt) = standard uncertainty of the net count rate of the tracer in counts per
second
u(At) = standard uncertainty of the activity of the tracer added to the sample
(pCi)
u(ε) = standard uncertainty of the detector efficiency
1213 If the critical level concentration (Lc) or the minimum detectable
concentration (MDC) are requested (at an error rate of 5) they can be
calculated using the following equations 3
2 For methods with very low counts MARLAP Section 19522 recommends adding one count each to the gross
counts and the background counts when estimating the uncertainty of the respective net counts This minimizes
negative bias in the estimate of uncertainty and protects against calculating zero uncertainty when a total of zero
counts are observed for the sample and background 3 The formulations for the critical level and minimum detectable concentration are based on the Stapleton
Approximation as recommended in MARLAP Section 20A22 Equations 2054 and 20A32 and Equation 2074
respectively (EPA 2004) The formulations presented here assume an error rate of α = 005 β = 005 (with z1minusα =
z1minusβ = 1645) and d = 04 For methods with very low numbers of counts these expressions provide better estimates
than do the traditional formulas for the critical level and MDC
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 16 Revision 0
aatas
ttt
b
s
b
sbba
b
s
b
s
cIDRVt
IDAt
t
t
ttR
t
t
t
t
L
140645116770140
aatas
ttt
b
ssba
b
s 13291271
MDCIDRVt
IDAt
ttR
t
t
where
Rba = background count rate for the analyte in the defined ROI in counts
per second
122 Results Reporting
1221 The following data should be reported for each result volume of sample
used yield of tracer and its uncertainty and FWHM of each peak used in
the analysis
1222 The following conventions should be used for each result
12221 Result in scientific notation plusmn combined standard uncertainty
13 Method Performance
131 Method validation results performed prior to analyzing samples are to be documented
and reported as required
132 Expected processing time per batch of 10-20 samples plus QC
1321 For an analysis of a 02 L sample aliquant precipitation and preparation of
load solution takes ~1 h
1322 Purification and separation using cartridges and vacuum box system should
take ~2 h
1323 The sample test source preparation step takes ~075 h
1324 A four-hour counting time should be sufficient to meet the MQOs listed in
Step 14 assuming detector efficiency of 015ndash03 and radiochemical yield
of at least 05 A different counting time may be necessary to meet these
MQOs if any of the relevant parameters are significantly different
1325 Data should be ready for reduction ~8-9 h after beginning of analysis
14 Pollution Prevention The method utilizes small volume (2 mL) extraction chromatographic
resin columns This approach leads to a significant reduction in the volumes of load rinse
and strip solutions as compared to classical methods using ion exchange resins to separate
and purify the curium fraction
15 Waste Management
Rapid Radiochemical Method for Curium-244 in Water Samples
05-01-2017 17 Revision 0
151 Types of waste generated per sample analyzed
1511 Approximately 210 mL basic waste from the initial sample
preconcentration
1512 Approximately 65 mL of acidic waste from loading and rinsing the two
extraction columns will be generated
1513 Approximately 25 mL of acidic waste from the microprecipitation method
for source preparation will be generated The waste contains 1 mL of HF
and ~ 5 mL of ethanol
1514 TEVAreg
cartridge ndash ready for appropriate disposal
1515 DGA cartridge ndash ready for appropriate disposal
1516 These waste streams may contain low levels of 243
Am (added as tracer) 244
Cm (added to LCS) and other radionuclides as present in samples
152 Evaluate all waste streams according to disposal requirements by applicable
regulations
16 References
Cited References
161 EPA 2009 Method Validation Guide for Radiological Laboratories Participating in
Incident Response Activities Revision 0 Office of Air and Radiation Washington