原子炉圧力容器に対する確率論的健全性評価手法の実用化に向けた取組み
概要
Reactor pressure vessel (RPV) of the light water reactor is the most important safety related component. To prevent non-ductile fracture of RPVs during operation, the degree of irradiation embrittlement of RPV steels is monitored by surveillance tests, and structural integrity assessment of RPVs is conducted based on the test results. The assessment method based on probabilistic fracture mechanics (PFM) is known as a rational one in assessing the integrity of RPVs, and efforts for practical applications of the PFM method are actively promoted in foreign countries as well as Japan. In Japan Atomic Energy Agency, we have developed a PFM analysis code PASCAL4, which implements evaluation methods considering both irradiation embrittlement and pressurized thermal shock events for RPVs in pressurized water reactors. In addition, we have also developed a guideline which provides PFM analysis procedures and their technical bases. In this paper, improvements of PASCAL4 for enabling the PFM evaluation of RPV in boiling water reactors along with an analysis example are presented.
