Host: The Japan Society of Mechanical Engineers
Name : The 30th International Conference on Nuclear Engineering (ICONE30)
Date : May 21, 2023 - May 26, 2023
It is important to conduct a multi-unit probabilistic risk assessment (MUPRA) to correctly identify the risk of external hazards for a site with multiple units. In Japan, an earthquake is an important external hazard in site risk. In this study, we have developed a method to assess seismic-induced initiating events (SMUIE) frequencies in a multi-unit site.
To develop the method that can utilize insights and results in seismic single-unit probabilistic risk assessment (SUPRA), we have developed a method to estimate SMUIE frequencies by extending an initiating event classification tree method commonly used in Japan.
The proposed method generates SMUIEs by combining seismic initiating events available in seismic SUPRAs. In the SMUIE generation process, the following factors specific to a multi-unit site are considered: (1) failure of shared equipment among units, (2) cascading effects across units, and (3) correlation of response and correlation of capacity of SSCs among units. Then, the SMUIEs are identified by checking validities of the combination considering these factors.
In addition, this paper provides a preliminary evaluation using the proposed method.
