ERMSAR 2012, Cologne March 21 – 23, 2012
Pascal PILUSO (CEA)Seong-Wan HONG (KAERI)
Matjaz LESKOVAR (JSI)Presentation by François BOUSSARD (CEA)
On behalf of SERENA members
2011 CSARP/MCAPSep. 20-23, 2011
[email protected]. [email protected], [email protected]
Status of SERENA-2
ERMSAR 2012, Cologne March 21 – 23, 2012
Scope of SERENA Project Status of the SERENA Project
Experimental Program Analytical program
Concluding Remarks
Outline
ERMSAR 2012, Cologne March 21 – 23, 2012
Scope of SERENA Project
Phase 1 (started October 2003, 4 years) Mainly calculations evidencing some
discrepancy between the different codes but remaining under the max stress level design of a reactor vessel
The same exercise applied to ex-vessel concrete led to insufficient safety margins for the containment.
Phase 2 (started October 2007, 4 years) Carry out confirmatory research required to
reduce uncertainties on these phenomena and thus to an acceptable level for risk assessment.
ERMSAR 2012, Cologne March 21 – 23, 2012
Scope of SERENA Project- Partners in Phase 2
Started from Oct., 2007 and will be continued for four years.
KAERI and CEA: Operation agents
18 Orgs. from 11 countries are participating: Belgium (Tractebel-Engineering SUEZ) Canada (AECL) Finland (VTT) France (CEA, IRSN, EDF) Germany (GRS, IKE) Japan (JNES) Korea (KAERI, KINS, KMU) Slovenia (JSI) Sweden (SSM, KTH) Switzerland (PSI) USA (US NRC, UWM)
ERMSAR 2012, Cologne March 21 – 23, 2012
Scope of SERENA Project-Main Objective of Phase 2 (1)
To reduce the scatter of the predictions for Steam Explosion in order to be able to increase the confidence in the calculated
containment safety margins for ex-vessel reactor case conditions.
Experimental tests (TROI and KROTOS facilities) by: Providing the missing experimental data on one key
FCI phenomena: the prototypical corium composition (“material effect”) using a large spectrum of corium melts representative of accident scenarios.
Providing innovative experimental data : spatial and size distribution of corium melts and void fraction during premixing and at the time of explosion and its dynamics.
ERMSAR 2012, Cologne March 21 – 23, 2012
Scope of SERENA Project-Main Objective of Phase 2 (2)
Experimental tests (TROI and KROTOS facilities) by: Improving modelling on the basis of the new data to
obtain consistent predictions of cavity loading by ex-vessel steam explosion.
Doing work oriented for elaboration on the major effects which are related to the explosion strength.
Analytical work by: Improving of FCI models/codes for use in reactor
analyses by complementing the work performed in Phase-1 through integrating the results of the Phase-2 Experimental program.
Doing work oriented for safety analysis and quantification of the major effects which reduce the explosion strength.
ERMSAR 2012, Cologne March 21 – 23, 2012
Release hook
Tungsten crucible and load
Thermal screens
Pyrometer
Isolation ball valve
Rupture wire #1
Heating element
Rupture wire #2
Puncher
Pressure vessel
Test tube
Release cone
Guide tube
Pyrometer
Water level (1145 mm)
Trigger
Force sensor
Dynamic pressure transducers (K0-K6) Sacrificial thermocouples (ZT1-ZT10) Lateral thermocouples (TT1-TT6) Pressure transducers (C1-C3)
Level swell
Ground floor
Basement
X-Ray window positions in different tests
•5 kg of melt•1-D geometry•New release device•Fast X-ray camera•External trigger
•20 kg of melt•2-D geometry•Intermediate catcher•Tomography•External trigger
Prototypical corium compositions
Status of SERENA Project-Experimental Program (1)
R.F. Generator150 kW
ColdCrucible
Furnace VesselID 1300
706
110
403
727
1020
716
Pressure VesselID 2,000
450
764
500
460
100
634
470
1214
220
250
289
`
`
10
274
1930
250
50050
057
0
946
200
TestSection
IVT101
IVT102
IVT103
IVT104
IVT209
IVDP101
IVDP102
IVDP103
IVDP104
IVT201
VFDP103
VFDP102
VFDP101
PVT001PVDP001
PVT002PVDP002
PVT003PVDP003
200
200
200
200
200
300
PVSP005PVT005PVDP005GAS005
PVSP004PVT004PVDP004GAS004
FVSP001
Intermediatemelt catcherand release
valve assembly
852
IVT202
IVT203
IVT204
IVT205
IVT206
IVT207
IVT208
Ar gas supplyfor aerosol removal
FVT
Pyrometer-1
Pyrometer-2
200
295.46
125
L60050, nozzle
-460
0
570
1000
1500
2000
3790
4810Elevation (mm)
30 t
1750
Catcher,
Nozzle,
Water,
T.S.,
(Unit : mm)
Pyrometer-3
KROTOS Facility (CEA)
TROI Facility(KAERI)
ERMSAR 2012, Cologne March 21 – 23, 2012
Status of the SERENA Project-Experimental program (2)
The complementary and innovative features of KROTOS (CEA) and TROI (KAERI) facilities are used
KROTOS for investigating the FCI characteristics of prototypical corium melts in one-dimensional geometry and fine characterization of the premixing thanks to X-Ray fast radioscopy able to distinguish corium, water and void. Essential for computer code model
improvement TROI for investigating the FCI behaviour in reactor-like
conditions by having more mass and multi-dimensional melt water interaction geometry. Suitable for validating the capability of
the computer codes in reactor-like situations.
ERMSAR 2012, Cologne March 21 – 23, 2012
Status of KROTOS : experimental Program (3)
KROTOS TROI
1 Challenging conditions
High melt superheat High system pressure(0.4 MPa, Room water temp.)
High system pressure (0.4 MPa) Reduced free fall (Melt jet velocity) and thick melt jet (Room water T.)
Mat 1: 70%UO2-30%ZrO2
2 Geometry effect Effect of geometry by comparison between KROTOS and TROI
Standard conditions: jet of diameter 3 cm
Large jet at penetration (5 cm)
Mat 1: 70%UO2-30%ZrO2
3 Reproducibility tests
Idem Test 2 Idem Test 2
4 Material effectOxidic composition
Standard conditions: jet of diameter 3 cm
Large jet at penetration (5 cm)
Mat 2: 80%UO2-20%ZrO2
5 Material effect Oxidation/composition
Standard conditions: jet of diameter 3 cm
Large jet at penetration (5 cm)
Mat 3: 70%UO2-15%ZrO2 + 15%Zr6 Material effect
Large solidus/liquidus T
Standard conditions. Effect of fission product: higher melt superheat
Large jet at penetration (5 cm).
Mat 4: 70%UO2-30%ZrO2 +FP+iron oxide
Performed
Performed
Performed
Performed (KS March 14th)
Performed
Status
Performed
ERMSAR 2012, Cologne March 21 – 23, 2012
KAERI and CEA performed all 6 TS and KS tests Triggered steam explosions in five tests out of 6 tests were
observed (KS and TS). The repeatable tests (TS-2 and TS-3) showed that many parameters
including dynamic pressure almost agree with each other. KS4 and TS-4 tests (80%UO2-20%ZrO2) both show larger explosion
load than other TS or KS tests respectively, except TS-6 and possibly KS6 (under analysis).
TS-5 test with added metallic Zr produced steam spike before triggering and no explosion was observed. KS-5 produced a triggered explosion (X-Ray confirmed).
TS-6 which has the lowest liquidus temperature and the largest solidification range shows the largest explosion of TS tests. KS6 is still under analysis (last week performed) and an energetic explosion has been observed.
Status of the SERENA Project- Experimental Program (5)
ERMSAR 2012, Cologne March 21 – 23, 2012
755
KROTOS KS3 - KS4
: 10 cm PF le 31/08/2010
K0-50
K2395
K1195
K3595
K4795
K5995
K61195
ZT2395
PyJ1637
Vidéo1595
ZT61195
ZT4795
ZT15295
ZT35695
ZT71543
ZT81642
TT080
TT1195
TT3595
TT5995
C1-67
C21495
TTM1495
TTL-67
Water: 1145 mm
Puncher : 1913 mm
TTV1920
Tin disc : 1900 mm
Rupture Wire F2 : 2316 mm
Trigger : 0 mm
SN
MS2010
X-ray845
CF-230
ZT101904
ZT91896
C31915
TTH1915
ZT1195
ZT3595
ZT5995
Dynamic pressure transducers
Sacrificial thermocouples
Lateral thermocouples
Pressure transducers
Optical mesurements
Water level transducer
Force sensor
Mass spectrometer
755
KROTOS KS3 - KS4
: 10 cm PF le 31/08/2010
K0-50
K2395
K1195
K3595
K4795
K5995
K61195
ZT2395
PyJ1637
Vidéo1595
ZT61195
ZT4795
ZT15295
ZT35695
ZT71543
ZT81642
TT080
TT1195
TT3595
TT5995
C1-67
C21495
TTM1495
TTL-67
Water: 1145 mm
Puncher : 1913 mm
TTV1920
Tin disc : 1900 mm
Rupture Wire F2 : 2316 mm
Trigger : 0 mm
SN
MS2010
X-ray845
CF-230
ZT101904
ZT91896
C31915
TTH1915
ZT1195
ZT3595
ZT5995
Dynamic pressure transducers
Sacrificial thermocouples
Lateral thermocouples
Pressure transducers
Optical mesurements
Water level transducer
Force sensor
Mass spectrometer
KROTOS: test section instrumentation
Status of the SERENA Project - Experimental tools (1)
ERMSAR 2012, Cologne March 21 – 23, 2012
Status of the SERENA Project - Experimental tools (2)
KROTOS : X-Ray radioscopy: fine characterization of premixing
Quantitative data
O
392 878
248
200
368
14°
1
2
3
4
5
6
78
Characteristics: Source: 6-11MeV - 0.33Gy/s
Exposure: 4.5 sResolution: 240x320Color depth: grey 12 bit
Fps: 55Duration: 1650 frames (20 sec)
Corium 3D Void 3D
Corium volumeCorium surface area
Void volumeVoid surface area
ERMSAR 2012, Cologne March 21 – 23, 2012
Status of the SERENA Project - Experimental tools (3)
Rayleigh-Taylor instability formation and stripping
Premixing and droplet formation
mechanism
KROTOS : X-Ray radioscopy: fine characterization of premixing
ERMSAR 2012, Cologne March 21 – 23, 2012
Status of the SERENA Project - Experimental tool (4)
KROTOS: post-test characterization of corium exploded and non exploded debris
ERMSAR 2012, Cologne March 21 – 23, 2012
Status of the SERENA Project - Experimental Outcomes (1)
TS and KS-4: inverse material effect: strongest explosion for composition with solidification
intervalKS and TS4: strongest
explosion never observed with protoypical materials
•FCI and material effects Before SERENA : After SERENA•Pure compound (alumina, corium azeotrope)=>Strong steam explosion
•Corium composition with solidification interval=>Weak steam explosion
•FCI and material effects Before SERENA: After SERENA:KS-5 and TS-5 weak explosion
•Oxidation effect: different reaction according to the nature of the material (oxide/”metallic”)•Simulant material #prototypical material=> impact on strength of the steam explosion
ERMSAR 2012, Cologne March 21 – 23, 2012
One of objectives : To reduce the scatter of the predictions in order to be able to put safety margins to containment failure
Have completed data base on the key phenomena for codes
Have provided more accurate experimental data Melt front location Mixing information jet break-up length (Krotos X-Ray system) Melt temperature Volume average void fraction Dynamic pressure and load
Status of the SERENA Project- Experimental Outcomes (2)
ERMSAR 2012, Cologne March 21 – 23, 2012
Status of the SERENA Project-Analytical Program (1)
The main tasks of the Analytical Working Group (AWG) are: Performing pre- and post-test calculations in
support of test specification and analysis. Improving analytical models and understanding
of those key phenomena that are believed to have a major influence on the FCI process.
Addressing the scaling effect and application to the reactor case.
Demonstrating the progress made in SERENA Phase-2 as compared with Phase-1 (in particular on reducing the scatter of the predictions) by repeating the “ex-vessel reactor exercise”.
ERMSAR 2012, Cologne March 21 – 23, 2012
Status of the SERENA Project-Analytical Program (2)
Applied FCI computer codes and organizations using them:
MC3D ; AECL, CEA+Tractebel, IKE, IRSN, JSI, KAERI, KINS, VTT.
TEXAS-V ; UWM, VTT. JASMINE ; JNES. JEMI (IKEMIX/IKEJET) + IDEMO ; IKE TRACER-II ; KMU Codes JEMI+IDEMO and MC3D are being
ongoing improved based on AWG findings
ERMSAR 2012, Cologne March 21 – 23, 2012
Status of the SERENA Project-Analytical Program (3)
Calculation of Experiments Performed pre- and post-test calculations
with accompanying sensitivity studies for performed experiments. Pre-test calculations for defining optimal test
conditions. Post-test calculations and sensitivity studies for
code validation, modeling improvements and as support for interpretation of experiments.
The observed differences of the simulation results between the codes and different modeling approaches, and the differences between the simulation results and experimental measurements have been analyzed and discussed.
ERMSAR 2012, Cologne March 21 – 23, 2012
Status of the SERENA Project-Analytical Program (4)
Calculation of Experiments Performed pre- and post-test calculations
with accompanying sensitivity studies for performed experiments;The calculations are focusing on the
understanding and modeling of key phenomena influencing FCI, with reactor applications in mind.
Post-test calculations of last experiments are underway.
ERMSAR 2012, Cologne March 21 – 23, 2012
Status of the SERENA Project-Analytical Program (5)
Reactor Case PWR: Bottom (2D) and Side Vessel Failure (3D) BWR: Bottom Vessel Failure (2D)
PWR (Bottom Failure)BWR (Bottom Failure)
ERMSAR 2012, Cologne March 21 – 23, 2012
Status of the SERENA Project-Analytical Program (6)
Reactor Case : Representative Initial conditions
ERMSAR 2012, Cologne March 21 – 23, 2012
Status of the SERENA Project-Analytical Program (7)
Reactor Exercise : Time Schedule June – October 2011: Calculations performed by AWG
members according to Reactor exercise specifications End of October 2011: Calculation results provided to
CEA coordinator November – December 2011: Preparation of draft
synthesis of calculations End of December 2011: Draft synthesis of
calculations submitted to Partners January – February 2012: Iteration of Draft synthesis March 2012: Final synthesis report submitted to
partners
ERMSAR 2012, Cologne March 21 – 23, 2012
Status of the SERENA Project-Analytical Program (8)
AWG Outcome document Reflects the elaboration process and
progress in the specific tasks, focusing on key phenomena influencing the FCI, with reactor applications in mind.Jet-breakup, Melt mass and void in
mixture, Melt solidification, Explosion phase, FCI modeling in integral codes.
ERMSAR 2012, Cologne March 21 – 23, 2012
Concluding Remarks (1)
Steam explosion is one of major unresolved issues in severe accidents after TMI-2.
TROI and KROTOS FCI tests: new accurate data and observation thanks to experimental tests using prototypical compositions
Experimental specific features and advanced measurement techniques on KROTOS and TROI facilities
Analyses of the full experimental results must be achieved in the next 6 months
The calculations are focusing on the understanding and modeling of key phenomena influencing FCI, with reactor applications in mind.
Application to reactor case to evaluate and decrease the scatter of results
ERMSAR 2012, Cologne March 21 – 23, 2012
Concluding Remarks (2)
OECD/NEA SERENA project A concluding seminar will be organised on 13-
15 Nov. 2012
Thank you for your attention
ERMSAR 2012, Cologne March 21 – 23, 2012
TS Plan (Actual) Features
1 Challenging conditions 0.4 MPa, 301K, Mat 1: 70%UO2-30%ZrO2 (73.4:26.6 )Trigger : ~0.85 s
S/EMax. C MPa
2 Geometry effect Effect of geometry by comparison between KROTOS and TROI
0.2 MPa, 334KMat 1: 70%UO2-30%ZrO2 ( 68:32)Trigger : ~0.85 sec
S/EMax. D2 Mpa
3 Reproducibility tests 0.2 MPa, 331KMat 1: 70%UO2-30%ZrO2 ( 71:29), Trigger : ~0.85 sec
S/EMax. D1 Mpa
4 Material effectOxidic composition
0.2 MPa, 333KMat 2: 80%UO2-20%ZrO ( 81:19 ), Trigger:~1.05 s
S/EMax. B Mpa
5 Material effect Oxidation/composition
0.2 MPa, 337KMat 3: 70%UO2-15%ZrO2 + 15%Zr
Steam Spike
6 Material effectLarge solidus/liquidus T
0.2 MPa, 338K, Mat 4: 70%UO2-30%ZrO2 +FP+iron oxide; 73. : 20.4 : 4.1 : 1.3 0.3 :0.8 :0.2 8.5 (UO2 : ZrO2 : Fe2O3 : Cr2O3: BaO:La2O3:SrO) 73.32: 18.45 : 4.885 : 1.74 : 0.385 : 0.975 : 0.24 ; Trigger : ~1.05s
S/EMax A Mpa
Status of the SERENA Project- Experimental Program (4)
TROI facility
ERMSAR 2012, Cologne March 21 – 23, 2012
Status of the SERENA Project - Experimental Program (7)
KROTOS (Actual) Features0 KF-C
Calibration test0.4 MPa, 302K, Tmelt=2930K, free fall: 0.570mMat 1: 70%UO2-30%ZrO2
S/E
1 KS-1Challenging conditions
0.4 MPa, 302K, Tmelt=2970K, free fall: 0.570mMat 1: 70%UO2-30%ZrO2
S/E
2 KS-2Geometry effect
0.2 MPa, 334K, Tmelt=3010K, free fall: 0.630mMat 1: 70%UO2-30%ZrO2
S/E
3 KS-3Reproducibility tests
0.2 MPa, 331K, Tmelt=3013K, free fall: 0.492mMat 1: 70%UO2-30%ZrO2
No S/E
4 KS-4Material effectOxidic composition
0.2 MPa, 333K, Tmelt=2970K, free fall: 0.492mMat 2: 80%UO2-20%ZrO2
S/EMax. value for SE
5 KS-5Material effect Oxidation/composition
0.2 MPa, 337K, Tmelt=2970K, free fall: 0.492mMat 3: 70%UO2-15%ZrO2 + 15%Zr
“Explosion”
KROTOS facility
ERMSAR 2012, Cologne, Germany, March 21 – 23, 2012
Background
Investigation of accident scenarios from core degradation to melt formation and relocation in the vessel, melt dispersion to the reactor cavity, MCCI and hydrogen related phenomena in severe accidents
The phenomena addressed in the studies are extremely complex and generally demand the development of specific research
The research field is too wide to allow investigation of all phenomena by any national programme
Existing experimental platforms should be opened for the transnational access to optimise the use of the resources at both national and international levels
29
ERMSAR 2012, Cologne, Germany, March 21 – 23, 2012
Acknowledgements
The authors gratefully acknowledge funding by Euratom and CAEA to support the work within ALISA project
30
ERMSAR 2012, Cologne, Germany, March 21 – 23, 2012
… and finally
Thank you for your attention!
31