ENVIRONMENTAL SAFETY Chapter 3 AND OCCUPATIONAL …4) KKNPP-1 was commissioned in 2013, due to which data reported for KKNPP-1 is from 2013 only. 5) Elevated tritium release at RAPS-1&2

51PBAERB Annual Report - 2016

ENVIRONMENTAL SAFETY AND OCCUPATIONAL

EXPOSURES3

Chap

ter

3.1 ENVIRONMENTAL SAFETY

Environmental safety in the vicinity of nuclear installation is ensured through control on radioactive discharges into the environment and environmental monitoring. These radioactive discharges are mainly in the form liquid and gaseous radioactive wastes produced during the operation of the installation.

AERBhasspecifiedthattheradiationdosetothe members of public near the operating NPPs due to the discharge from the plants shall not exceed annual limit of 1 mSv (i.e. 1000 micro-Sievert). This is in line with the limits recommended by International Commission on Radiological Protection (ICRP). Based on this limit, AERB has furtherspecified limitson liquidandgaseousradioactive discharges through gaseous and liquid routes,intheTechnicalSpecificationsforOperationofNPPs.Thesetechnicalspecificationlimitsaresetfar below the dose apportionment to the public for thespecificradionuclide.Theradionuclidespecificdose apportionment is small fraction of the annual dose limit (1mSv/year) to public. While specifying these limits, it is ensured that the discharge is controlled within public exposure limit of 1000 micro-Sievert following the principles of ‘As Low As Reasonably Achievable’ (ALARA). The limits specified in the technical specifications actuallyensure that the dose to the public is well below the specifiedlimitof1000micro-SievertforNPPsite.The actual discharges from the plants are seen to be wellbelowthelimitsspecified.

Periodicreportsincludingeffluentdischargesare submitted to AERB in prescribed forms. AERB also conducts regular inspection of these plant sites to verify compliance with the laid down requirements. Every five years, prior to renewalof license for operation of these facilities, the

adequacy of waste management arrangements, effluentreleaseandtheirimpactontheenvironmentare thoroughly reviewed.

The independent Environmental Survey Laboratories (ESL) of the Health, Safety and Environment Group, BARC carry out environmental surveillance at all the operating NPP sites. The liquid and gaseous radioactive wastes discharged to the environment during the year 2016 from the operating units were only a small fraction of the prescribedtechnicalspecificationlimits.Theliquidand gaseous discharges from the plant for the year 2012 to 2016 as percentage of limits prescribed in technicalspecificationsforoperationsofrespectivestations are presented in the Figures 3.1 (a) to 3.1(f).

Typical values for radioactive effluentdischarges from Indian 540 MWe PHWR (TAPS-3&4) for the year 2016 are given below, which are comparable to the reported discharges from other international nuclear power plants of this type.

Liquid Effluents GaseousEffluents Solid Rad. Waste

Produced

Tritium (Bq/Unit)

Tritium (Bq/Unit)

FPNG (Bq/Unit)

Volume (M3/Unit)

Activity (Bq/Unit)

2.10E+13 3.30E+13 5.00E+13 37.00 1.27E+15

Radiation dose to members of the public near the operating plants is estimated based on gaseous releases and measurements of radionuclide concentration in items of diet, i.e. vegetables, cereals, milk,meat,fish,etc.and through intakeofairandwater. It is seen that the effective dose to public around all NPP sites is far less than the annual limit of 1mSv (1000 micro-Sievert) prescribed by AERB. The effective doses to the members of the public due tothereleaseofradioactiveeffluentsfromtheplantsare presented in the Figures 3.2 (a) and 3.2 (b).

5352AERB Annual Report - 2016

Notes:1) TAPS-1&2 are Boiling Water Reactors. Hence, there is no generation / discharge of Tritium.2) The data of MAPS pertains to transfer of liquid waste to Centralised Waste Management Facility (CWMF), Kalpakkam

for processing and discharge to the environment.3) At KKNPP-1, during operation of the reactor, a small amount of tritium gets generated. The station is authorised to

dischargeaminisculeamountof tritiumthrough itseffluent,after treatment.Theauthorised limitsbeingverysmall,thedischargesare reflectedassignificantpercentageofauthorised limit,even though theactualdischargeamount isnegligible from radiological safety considerations.

4) KKNPP-1 was commissioned in 2013, due to which data reported for KKNPP-1 is from 2013 only.5) Elevated tritium release at RAPS-1&2 was due to dousing tank draining in the month of April-May 2016 (with

authorisation from AERB).

Note: Gross beta activity value reported by MAPS-1&2 is the activity transferred to CWMF of BARC. The Gross beta activity inliquideffluentreleasewashighintheyear2013asUnit-2wasshutdownfor209days.GrossBetaactivityreportedbyKGS-1&2 and KGS-3&4 are the activity transferred to Waste Management Centralised Facility (WMCF) of Kaiga Site.


Note: TAPS-1&2 are Boiling Water Reactors. Hence, there is no generation / discharge of Tritium. KKNPP–1 is PWR, there is no discharge of tritium through gaseous route.

Note:Argon-41releasefromRAPS-1&2andMAPSarehighascomparedtootherunitsduetoairfilledcalandriavaultanduseof air for annular gas system.


Note:In the technical specifications ofTAPS-1&2, the limit for Iodine -131 releases includes the discharge of particulateactivity also.


Note: Public dose at Rawatbhata and Kalpakkam site is relatively higher as compared to other reactor sites, due to release of Ar-41 from RAPS-2 and MAPS.

Note: Public dose at Rawatbhata and Kalpakkam site is relatively higher as compared to other reactor sites, due to release of Ar-41 from RAPS-2 and MAPS.


3.2 OCCUPATIONAL EXPOSURES In each NPP, a Radiological Safety Officer(RSO) and alternate RSO are designated by the Competent Authority to implement the radiation protection programme. The RSOs are entrusted with the responsibility for providing radiological surveillance and safety support functions. These include radiological monitoring of workplace, plant systems,personnel,radioactiveeffluents,carryingout exposure control, exposure investigations and analysis and trending of radioactivity in plant systems.

All NPPs have radiation safety programme and work procedures intended to control the occupational exposures. As per AERB directives, for an occupational worker annual dose limit is 30 mSv, with the condition that it should not exceed 100mSvinaspanof5years.Thespecifiedannual

dose constraint for radiation exposure of temporary worker is 15 mSv.

For better exposure control, individual cases are investigated and controlled at an early stage so astoremainwithintheAERBspecifieddoselimits.Following Investigation Levels (ILs) are applicable to the nuclear facilities.

Monthly dose - 10 mSvQuarterly dose - 15 mSvAnnual dose - 20 mSv

The information on number of workers in NPPs who received dose between 20 to 30 mSv and above 30 mSv during the year 2016 is given in Table: 3.1. In the year, 2016 there was no case of individual radiation exposure above the prescribed annual dose limit of 30 mSv. The maximum individual radiation dose was 18.15 mSv during the year.

Table 3.1 Radiation Doses Received by Workers in NPPs (2016)

NPP Number of monitored

persons

Average dose for

monitored person (mSv)

No. of persons received

dose

Average dose among dose

receivers(mSv)

Number of workers received dose in the range

< 20

(mSv)

20-30

(mSv)

>30

(mSv)

TAPS-1&2 1221 1.96 920 2.61 1221 0 0

TAPS-3&4 1431 1.73 1150 2.16 1431 0 0

RAPS-1&2 1036 2.55 822 3.22 1036 0 0

RAPS-3&4 1507 1.55 1124 2.08 1507 0 0

RAPS-5&6 1236 0.84 845 1.23 1236 0 0

MAPS-1&2 1194 1.34 1074 1.49 1194 0 0

NAPS-1&2 1413 1.87 1128 2.35 1413 0 0

KAPS-1&2 1297 1.86 1030 2.34 1297 0 0

KGS-1&2 1408 1.30 1102 1.66 1408 0 0

KGS -3&4 1156 0.45 647 0.81 1156 0 0

KKNPP-1 2183 0.039 175 0.48 2183 0 0


Figure 3.3 gives collective dose for operation and maintenance of NPPs for Last 5 Years.

The information on number of workers in medical, industrial and research institutions, who receieved various doses during the year 2016 is given in Table-3.2

Table-3.2 Radiation Doses (Effective) received by workers in Medical, Industrial and Research Institutions

in the Year 2016*Category

of radiation worker

No. of monitored

persons

Averaged dose for

monitored persons (mSv)

No. of persons

receiving dose

greater than zero

Average Dose for persons

receiving dose > zero

No. of workers receiving annual individual dose excluding zero

dose D(mSv)0<D

<20

20<D

<30

30<D

<40

40<D

<50

D>50

Diagnostic X-rays

92689 0.27 35537 0.7 35517 18 2 0 0

Radiation Therapy

12918 0.18 4773 0.49 4773 0 0 0 0

Nuclear Medicine

2569 0.51 1562 0.84 1562 0 0 0 0

IR & Rad. processing

7281 0.43 2712 1.16 2702 8 0 1 1

Research 4086 0.12 1073 0.46 1073 0 0 0 0Total 119543 0.27 45657 0.71 45627 26 2 1 1

* Data (External dose) as on April 28, 2017 with National Occupational Dose Registry System (NODRS). The data does not include exposure cases above investigation levels which are currently under investigation.

The information on number of workers in medical, industrial and research institutions, who exceeded radiation exposures in different ranges during the year 2015, was given in Table-5.2 of AERB annual

report for the year 2015-16. The information for the year 2015 is now updated incorporating the outcome of excessive exposure cases that have been concluded and is given in Table 3.2(a) below.


Table-3.2 (a)Radiation Doses (Effective) received by workers in Medical, Industrial and Research Institutions during 2015* (updated after investigations on workers who have received doses above investigation the year and receipt of more data)

Category of radiation worker

No. of monitored

persons

Averaged dose for

monitored persons (mSv)

No. of persons

receiving dose greater

than zero

Average Dose for persons

receiving dose > zero

No. of workers receiving annual individual dose excluding zero dose

D(mSv)

0<D <20

20<D<30

30<D<40

40<D<50

D>50

Diagnostic X-rays

78929 0.36 34158 0.84 34117 28 4 1 8

Radiation Therapy

11969 0.21 4717 0.53 4717 0 0 0 0

Nuclear Medicine

2473 0.92 1642 1.39 1639 2 0 0 1

IR & Rad. Processing

7446 0.55 2732 1.5 2719 6 3 1 3

Research 4079 0.16 1395 0.46 1395 0 0 0 0Total 104896 0.36 44644 0.85 44587 36 7 2 12

* Data (External dose) as on April 28, 2017 with National Occupational Dose Registry System (NODRS). The data does not include exposure cases above investigation levels which are currently under investigation.

The information on number of workers in various Fuel Cycle Facilities who received radiation doses

less than 20 mSv, between 20 to 30 mSv and above 30 mSv during the year 2016 is given in Table 3.3.

Table- 3.3Radiation Doses Received by Workers in Front End Fuel Cycle Facilities

Type of Facilities

Location Number of

Exposed Persons

Average Dose for Exposed Persons (mSv)

Maximum Dose of Exposed Persons (mSv)

No. of workers received dose in the

range

< 20 mSv

20 – 30 mSv

>30mSv

Uranium mines (UCIL)

Jaduguda 82 0.85 1.27 82 0 0

Bhatin 112 0.27 0.71 112 0 0

Narwapahar 911 4.25 7.37 911 0 0

Turamdih 651 3.90 8.73 651 0 0

Bagjata 690 4.59 7.35 690 0 0

Banduhurang 351 3.08 4.10 351 0 0

Mohuldih 320 2.56 4.84 320 0 0

Tummalapalle 1090 5.72 13.73 1090 0 0


Type of Facilities

Location Number of

Exposed Persons

Average Dose for Exposed Persons (mSv)

Maximum Dose of Exposed Persons (mSv)

No. of workers received dose in the

range

< 20 mSv

20 – 30 mSv

>30mSv

Uranium mill (UCIL)

Jaduguda 1061 2.87 6.23 1061 0 0

Turamdih 739 1.26 2.46 739 0 0

Tummalapalle 322 0.31 1.15 322 0 0

Thorium mines and mills (IREL)

Chavara 70 0.35 2.51 70 0 0

Manavalakurichi 156 1.78 8.96 156 0 0

Chatrapur 429 3.14 18.75 429 0 0

Udyogamandal 274 0.93 15.17 274 0 0

Fuel Fab. (NFC) Hyderabad 1266 0.81 8.1 1266 0 0

Total 8524 8524 0 0

3.3 BASIS FOR ACCEPTABLE DOSE TO OCCUPATIONAL WORKERS AND ENVIRONMENTAL RELEASES

The dose limits for exposure from ionising radiation for occupational workers and the members of the public are prescribed by AERB in its Directive No.01/2011 under Rule 15 of the Atomic Energy (Radiation Protection) Rules, 2004. These dose limits are based on the ICRP recommendations and IAEA safety standards on Radiological Protection and are in line with the international practice and standards. The estimated dose to the members of the public due to discharge of radioactive effluentsfrom nuclear facilities at a site shall not exceed an effective dose of 1 mSv in a year.• Observance of Dose Limits The exposure control consists of application of primary dose limits, action levels such as investigation level and operational restrictions. Operational restrictions are established based on dose, dose rate, air activity and surface contamination levels etc., at workplace such that the exposure of workers does not exceed the applicable dose limits. Individual exposures exceeding the investigation levels are investigated and reported to AERB. All cases of exposures exceeding the annual limits are reviewed by AERB committee.

• Authorised Limits of Environmental Releases / Discharge

The discharge of radioactive waste from a NPP is governed by the Atomic Energy (Safe Disposal of Radioactive Wastes) Rules, 1987. It is mandatory for the NPP to obtain authorisation under these rules from the Competent Authority fordisposalofradioactivewastesandfileareturnannually to AERB indicating the actual quantity of radioactive waste discharge.

Discharge constraints are set at a much lower value than the authorised limits to achieve effluentreleasesatALARAlevel.Thesedischargeconstraints are usually set at 50-65% of authorised discharge limits taking into cognizance differences in NPP system design. The operating data shows that releases from NPPs have been a small fraction ofthespecifiedreleaselimits.

3.4 INITIATIVES TAKEN BY AERB FOR DOSE REDUCTION

(i) Review of Radiation Protection Aspects during Project Stage

During the design and commissioning, it is ensured that an elaborate radiation monitoring system consisting of area radiation monitors, process monitors, environmental monitors and effluentmonitors are available to give history, trend and

PB60AERB Annual Report - 2016

instantaneous readings of the monitors for exposure control. Based on the operating experience, many designmodificationsforexposurecontrolhavebeenincorporated progressively in the Indian NPPs.

(ii) Operation Phase Radiation protection programme during the operation of NPPs is revised and approved by AERB. This programme comprise of organisational, administrative and technical elements. ALARA measures in exposure control of the plant personnel and the public.

AERB ensures that plant management makes adequate review of the implementation and the effectiveness of the radiation protection programme. Radiological safety officer (RSO)for each NPP is authorised by AERB to carry out radiological safety functions.

The environmental surveillance programme is also reviewed to evaluate the impact of operation of the NPP on the surroundings areas of the plant site and ensure that effluent releases and publicexposures are below the regulatory limits.

(iii) Collective Radiation Dose Budgeting Annually the collective dose budget is prepared by each NPP based on the jobs that are likely to be executed and collective dose consumed in the previous years as well as the existing radiological condition in the plant. The aim is to minimise the collective dose in line with ALARA principle. AERB carries out review of the budget. Any upward revisionofthebudgetrequiresadequatejustificationby NPP, review and approval by AERB.

(iv) Review of Radiological Safety Aspects Routine quarterly and annual reports on radiological safety aspects are prepared by the RSO of the NPP. The reports are reviewed at AERB and necessary corrective measures required for exposure control are recommended to respective NPP.

(v) Regulatory Inspection During the regulatory inspection environmental monitoringdata,effluentdischargedata,radioactivewaste disposal data and quality assurance programme in radiation protection are checked. Additionally,

AERB also conducts regulatory inspections during Biennial Shutdown (BSD)/Refuelling Shutdown (RSD) of NPPs to ascertain compliance with radiation protection procedure.

(vi) Review of Radiation Exposure to Occupational Workers

The radiation exposure to the occupational workers is periodically reviewed by AERB based on the health physics reports. The exposure cases exceeding the regulatory constraints/ limits are primarily investigated by the exposure investigation committee at each NPP and subsequently by the AERB Safety Committees.

(vii) Exposure Control and Implementation of ALARA

AERB ensures that all nuclear plants have radiation safety programs and work procedures intended to control the occupational exposures. Exposures to site personnel are controlled by a combination of radiation protection measures such as:

a) All NPPs have ALARA committees at station level and sectional level. Periodic ALARA reviews are conducted at the NPPs to identify areas for dose reduction and to implement corrective actions.

b) The operating experience on radiological events at NPPs in India and in other countries is reviewed and the lessons learned are communicated to all concerned station personnel.

c) Improved Collective Dose budgeting.

d) Restricting the external exposure by means of shielding, remote operation, source control, rehearsing the work on mock ups and minimising the exposure time.

e) Minimising the internal exposures by source control.

f) Periodic review of radioactive work practices.

g) Periodic training of radiation workers on radiation protection aspects.

ENVIRONMENTAL SAFETY Chapter 3 AND OCCUPATIONAL …4) KKNPP-1 was commissioned in 2013, due to which data reported for KKNPP-1 is from 2013 only. 5) Elevated tritium release at RAPS-1&2

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