Nuclear Techniques ›› 2018, Vol. 41 ›› Issue (10): 100605-100605.doi: 10.11889/j.0253-3219.2018.hjs.41.100605

• NUCLEAR ENERGY SCIENCE AND ENGINEERING • Previous Articles     Next Articles

Uncertainty analysis of in vessel retention in three-layer melt pool configuration

CAO Zhen, CAO Kemei, WANG Jiayun   

  1. Shanghai Nuclear Engineering Research & Design Institute Co., Ltd., Shanghai 200233, China
  • Received:2018-05-02 Revised:2018-07-18 Online:2018-10-10 Published:2018-10-16

Abstract: [Background] Uncertainty exists in melt pool parameters when postulated severe accident occurs in reactor, and heat flux distribution obtained by two-layer or three-layer melt pool configuration would vary from each other, hence it is necessary to analyze the uncertainty of in vessel retention (IVR) in different configurations.[Purpose] This study aims to investigate quantization uncertainty brought by three-layer configuration.[Methods] First of all, the self-developed code SPIRE was employed to verify with references and analyze the uncertainty of IVR in three-layer melt pool configuration based on core damage frequency (CDF). The input parameters were obtained according to the simulation results of accident scenarios. Then the three-layer melt pool configuration results were compared with that of two-layer melt pool configuration. Finally, uncertainty analysis was carried out based on Monte Carlo sampling and sensitive analysis.[Result] Compared with the two-layer melt pool configuration results, the safety margin at bottom of melt was decreased notably whilst safety margin at top of ceramic layer was increased. In 125 000 cases generated by sampling, conditional failure probability in two-layer condition is 0, while in three-layer condition is 7.11×10-5 (failure occurred in light metallic layer).[Conclusion] Sensitivity analysis showed that, within the scope of this study, the probability distribution for input parameters had little influence on the result; conditional failure probability was notably affected by the uranium oxidation fraction; melt fraction of core had certainty influence on safety margin at top of ceramic layer.

Key words: In vessel retention, Uncertainty analysis, Monte Carlo sampling

CLC Number: 

  • TL364+.4