Technical review of structural integrity assessment procedure on reactor pressure vessel, 2; Effects of transient loads on brittle fracture initiation

Masaki, Koichi; Osakabe, Kazuya*; Nishikawa, Hiroyuki*; Katsuyama, Jinya  ; Onizawa, Kunio 

The structural integrity of a reactor pressure vessel (RPV) should be maintained to ensure the safe long-term operation of a nuclear power plant. Probabilistic fracture mechanics (PFM) code is required to assess the structural integrity of a RPV during pressurized thermal shock (PTS) events quantitatively. The PASCAL3 for probabilistic analysis have been developed in JAEA. In PTS reevaluation project in the United States, PFM analysis using FAVOR has been conducted to obtain screening criteria for PTS. To consider the future application of the probabilistic method to the code in Japan, we have conducted deterministic and probabilistic analyses using PASCAL3 and evaluated the effects of transient loads on brittle crack initiation and fracture. The results showed that the structural integrity of a RPV could be assessed quantitatively through the evaluation of fracture probabilities.