Development of failure mitigation technologies for improving resilience of nuclear structures, 20; Effectiveness evaluation methodology of the measures for improving resilience against excessive earthquake

Kurisaka, Kenichi ; Nishino, Hiroyuki  ; Yamano, Hidemasa   

This study aims to evaluate the effectiveness of the measures for improving resilience against excessive earthquake. Loss of heat removal systems (LORHS) after reactor shutdown is focused on. Implementation of those measures could prevent the seismic-induced LOHRS itself or core damage due to ultra-high temperature condition resulting from LOHRS. Based on this, we developed the methodology that the effectiveness is evaluated by the reduction of core damage frequency. As an example, its applicability to sodium-cooled fast reactors was examined.