Development of fault displacement PRA methodology and its application to a hypothetical NPP

Abstract

The authors have developed fault displacement (FD) probabilistic risk assessment (PRA) methodology, through application to a hypothetical nuclear power plant (NPP).Core damage frequency (CDF) and its uncertainty of a hypothetical NPP for dip-slip faults and strike-slip faults were evaluated using a probabilistic FD hazard, FD fragilities of building and components, and fault tree and event tree models. Important initiating events, accident sequences, components and structure failures, as well as the range of FD that characterize the core damage risk profile were identified. Through the study, the authors confirmed the feasibility of the methodology, and also identified the important source of uncertainties within the methodology that require further development. Risk insights obtained from the FD PRA can be used to investigate countermeasures to reduce the FD risk.