[3J01-05] SeismicPRA

[3J01] A Framework of RI-PB Design Application for Seismic Events

Part 13 : Balancing system risk in existing plants

*Noa Matsumaru¹, Yasuki Ohtori¹, Hitoshi Muta¹, Toshiaki Sakai², Yoshifumi Katayama³ (1. TCU, 2. CRIEPI, 3. Chuden Engineering Consultants)

Keywords:Risk Informed Performance Based, Optimum Design, Risk Profile

In the 2022 AESJ spring meeting, we demonstrated the risk balancing of a RHR system of nuclear facility which is expected to be newly built as a part of RI-PB design framework. In the balancing process, Fussell-Vesely (FV) importance measure is used as balancing index and initial values of failure probabilities are assigned based on the literature (Vaishanav et al., 2020). Although the balanced risk profile was successfully obtained, some of failure probabilities were larger than those of initial values, whose situation is unrealistic for existing plants. This paper demonstrates the balancing the risk profile with constraints which are determined based on the conditions of existing power plants.