부산대학교 도서관

The purpose of this study is to investigate the effects of the difference between analytical methodologies for seismic probabilistic safety assessment (PSA), especially the difference in the probability of system failures and core damage sequences. We selected two methods, upper bound approximation (UBA) using minimal cut sets and direct quantification using Monte Carlo simulation (DQFM) for comparison. The former is often used in PSA for both internal and external event. The latter is developed in Japan Atomic Energy Agency (JAEA) as a part of SECOM2, a system reliability analysis code for seismic PSA, and expanded to divide the core damage state into different core damage sequences. The result showed that there is a significant difference between UBA method and DQFM method.