Modeling of containment isolation system for risk informed application

CDF(Core Damage Frequency) and LERF(Large Early Release Frequency) are two important values used for evaluation of risk significance for the risk-informed application. In domestic nuclear field, it is expected that LERF as well as CDF has to be evaluated to apply the risk-informed technology. The analysis depth for the containment isolation failure handled in the existing PSA Level 2 model is not enough to evaluate the LERF used in the risk-informed application. Accordingly, the systematical analysis model for the containment isolation system to evaluate the LERF is required. The paper provides the analysis model of containment isolation system based on the reference plant (Ulchin Units 3 and 4)