[3J10-14] HRA/CMF/Decommissioning

[3J12] Importance Measure Considering Common Cause Failure

Part 2: seismic vulnerability meaure against unexpected multiple damage

*Yasuki Ohtori¹, Hitoshi Muta¹, Toshiaki Sakai² (1. Tokyo City University, 2. CRIEPI)

Keywords:importance measure, vulnerability , multiple damage, Common cause failure, seismic PRA

In nuclear power generation facilities, there is a possibility that latent defects may simultaneously surface due to design errors or other causes that were not anticipated at the time of design, resulting from earthquakes. It is important to evaluate the vulnerability of a plant system when multiple SSCs are damaged simultaneously due to unexpected causes prior to the occurrence of an earthquake. This paper proposes an importance measure to quantify the vulnerability of a system to earthquake-induced component damage, which includes not only expected component damage considering dependency (correlation), but also unexpected multiple damage induced by an earthquake.