Study on structural integrity assessment methodology of reactor pressure vessel based on probabilistic fracture mechanics analysis

Onizawa, Kunio ; Nishikawa, Hiroyuki*; Katsuyama, Jinya  

In order to provide technical basis on the validity of structural integrity assessment procedure for reactor pressure vessel (RPV), PFM Analysis code PASCAL2 has been improved into PASCAL3 by incorporating the following additional functions. (1) Stress intensity factor calculation method for surface crack developed by CEA, (2) Embrittlement prediction method developed by the CRIEPI based on domestic surveillance data, and (3) Newly developed Weibull-type fracture toughness evaluation equation of fracture toughness and crack arrest toughness based on fracture toughness data in Japan. Sensitivity analyses using PASCAL3 were performed to evaluate a standard analysis condition for probabilistic structural integrity assessment of RPV. In addition, we evaluated the effect of weld-overlay cladding on the structural integrity assessment of RPV by using detailed analysis results of weld residual stress near the cladding by FEM.