Abstract:Based on risk spectrum software, impact analysis of common case failure (CCF) of AP1000 passive residual heat removal system (PRHRS) was carried out by applying multiple Greek letter model (MGL). Situation with and without CCF were both calculated. Without CCF, the PRHRS failure probability is 9.559×10^-6. With CCF, the PRHRS failure probability is 2.008×10^-4. In this comparison, we can find that, without considering CCF, the PRHRS is mainly effected by heat exchanger leakage and IRWST failure. And, with considering CCF, the main cause of PRHRS failure is pneumatic valve CCF.

Keywords:multiple Greek letter model (MGL), passive residual heat removal system (PRHRS), common case failure (CCF), heat exchanger, incontainment refueling water storage tank (IRWST), pneumatic valve