Recent activities on validation of modelling of thermal-hydraulic and aerosol phenomena in ASTEC CPA Ivo KLJENAK1, Maik DAPPER2, Jiri DIENSTBIER3, Luis E. HERRANZ4, Mohammed BENDIAB2, Marco K. KOCH2, Joan FONTANET4 1) Jozef Stefan Institute 2)

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Recent activities on validation of modelling of
thermal-hydraulic and aerosol phenomena in ASTEC
CPAIvo KLJENAK1, Maik DAPPER2, Jiri
DIENSTBIER3, Luis E. HERRANZ4, Mohammed
BENDIAB2, Marco K. KOCH2, Joan FONTANET41)
Jozef Stefan Institute2) Ruhr-Universitaet
Bochum 3) Nuclear Research Institute Rez 4)
Centro de Investigaciones Energeticas Medio
Ambientales y Tecnologicas
ERMSAR 2007FZ Karlsruhe, June 12-14, 2007
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INTRODUCTION

• Validation of the ASTEC V1.2 CPA modeling of
  thermal-hydraulic, aerosol and fission product
  phenomena.
• Simulations of transients in containment systems
  of different scales
• Small-scale experimental facilities (comparison
  with experiment)
• PHEBUS containment vessel
• KAEVER vessel
• Large-scale experimental facilities (comparison
  with experiment)
• LACE facility
• Battelle Model Containment
• Real-scale system (comparison with MELCOR)
• VVER-1000 NPP containment

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Facilities and transients
PHEBUS Containment (IRSN Cadarache)

• Experiment FPT2
• Injections in containment
• steam, H2, N2,
• aerosols.

Volume 10.0 m3 3 condensers CPA model 3 c.v.
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Facilities and transients
KAEVER Vessel (Becker Tech., Eschborn)

• Purpose aerosol behaviour in saturated and
  non-saturated atm.
• Injections
• steam, N2,
• aerosols (soluble CsOH, CsI, non-soluble Ag,
  mixtures).
• Tests
• K188 CsOH aerosols
• K186 CsOHAg aerosols
• K187 CsOHCsIAg aeros.
• K123 CsI aerosols
• K148 Ag aerosols

Volume 10.6 m3 CPA model 1 c.v.
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Facilities and transients
Battelle Model Containment (Battelle, Eschborn)

• Experiment PACOS Px1
• Sequence Px1.2
• (R7 sealed, vol. 600 m3)
• Purposes
• steam-air mixing in containment,
• influence of containment sprays.
• Phase 1 steam injection, sprays
• Phase 2 steam inject. X 3, sprays
• Phase 3 spray flow rate increased
• Phase 4 no steam injection, sprays

Volume 640 m3 CPA model 23 c.v.
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Facilities and transients
LACE Vessel (Westinghouse)

• Experiment LA4
• Purpose aerosol behaviour in containment
• Aerosols
• CsOH (soluble)
• MnO (non-soluble)
• Experiment 8 phases
• 1 steam injection
• 2 CsOH, steam, carrier gas
• 3 CsOH MnO, steam, carrier gas
• 4 MnO, steam, carrier gas
• 5 steam
• 6 containment venting
• 7 cooldown (closed vessel)

Volume 852 m3 CPA model 1 c.v.
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Facilities and transients
VVER-1000/320 Containment

• Balakovo NPP (Temelin NPP)
• ABH scenario
• Hot leg large-break LOCA with blackout (ECCS and
  sprays not actuated)
• Start double-ended break of a circul. loop
• Core uncovery
• Later vessel bottom head failure
• Steam injection, H2 injection, heat transfer from
  primary system modelled as external sources.

CPA model 6 c.v.
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RESULTS Thermal-hydraulics
PHEBUS Containment pressure atm. temperature
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RESULTS Thermal-hydraulics
KAEVER Containment pressure atm. temp. (test
K187)
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RESULTS Thermal-hydraulics
PACOS Containment pressure
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RESULTS Thermal-hydraulics
PACOS Atmosphere temperature
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RESULTS Thermal-hydraulics
LACE Containment pressure atm. temperature
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RESULTS Thermal-hydraulics
VVER-1000/320 Containment pressure Comparison
ASTEC CPA - MELCOR
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RESULTS Aerosol and FP behaviour
PHEBUS Aerosol concentration in atmosphere
Cesium
Iodine
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RESULTS Aerosol and FP behaviour
KAEVER Aerosol dry and wet concentration
Test K187 CsOH, CsI, Ag aerosols
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RESULTS Aerosol and FP behaviour
LACE Aerosol dry concentration
CsOH soluble
MnO non-soluble
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RESULTS Aerosol and FP behaviour
VVER-1000/320 Aerosol and noble gases
concentration Comparison ASTEC CPA - MELCOR
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CONCLUSIONS

• Several experiments and hypothetical scenario in
  facilities of different scales simulated with
  ASTEC CPA module
• Thermal-hydraulic phenomena
• Good general agreement between simulation and
  experimental / other code results.
• Largest differences observed for temperature in
  small and large scale systems, and in real-scale
  system between ASTEC/CPA and MELCOR in wall heat
  transfer
• Aerosol behaviour
• Dry aerosol concentrations in vessels well
  simulated in small and large scale systems.
• Deficiencies identified in small-scale
  facilities
• slight overprediction of aerosol sedimentation,
• low deposition rate of wet aerosols.