Atomic Energy Society of Japan

In the structural integrity assessment of reactor pressure vessels (RPVs) based on probabilistic fracture mechanics (PFM), it is important to consider the probability distribution of embrittlement due to neutron irradiation. In this presentation, we report the specific method of introducing the Bayesian nonparametric (BNP) method, which is a statistical analysis method based on machine learning and Bayesian statistics, into the PFM analysis code PASCAL. The results of the study on the of the difference between the BNP method and the current Japanese standard on the failure probability of RPVs are reported.