[1H01-07] Resilience of Nuclear Structures

[1H05] Development of Failure Mitigation Technologies for Improving Resilience of Nuclear Structures

(27) Preliminary Evaluation for Effectiveness of the Measures for Improving Resilience against Excessive Earthquake

*Hiroyuki Nishino¹, Kenichi Kurisaka¹, Hidemasa Yamano¹ (1. Japan Atomic Energy Agency)

Keywords:measures for improving resilience, excessive earthquake, fragility evaluation, accident sequences, core damage frequency

In conventional seismic evaluation of reactor vessel (RV), buckling has been regarded as loss of function. This study considers that actual loss of function is caused by accumulation of fatigue damage after buckling, and this consideration in the evaluation is regarded as the measure for improving resilience of RV against excessive earthquake. Based on this, we evaluated preliminarily the probability to lose the RV function (i.e., fragility) and core damage frequency in the excessive earthquake before and after improving resilience to show effectiveness of the measure.