How to reasonably estimate the contribution of inter-unit common cause failure(CCF)to the safety risk of power plant is an important technical problem that needs to be solved in multi-unit probabilistic safety analysis(PSA)modeling.In this study,analysis methods of inter-unit CCF group selection,modeling and parameter estimation are presented,and the loss of offsite power(LOOP)event of a four-unit pressurized water reactor(PWR)nuclear power plant is taken as an analysis case to quantitatively evaluate the change of core damage frequency(CDF)of multi-unit PSA model before and after considering CCF.The results show that after considering the inter-unit CCF,the frequency of core damage(CD)occurrence in only single unit and the frequency of CD occurrence in multiple units will increase.It can be seen that inter-unit CCF has a certain effect on multi-unit PSA results.
Multi-unitProbabilistic safety analysis(PSA)Common cause failure(CCF)analysisCore damage frequency(CDF)