Development of failure probability evaluation methodology of passive safety function in level-1 PSA for sodium-cooled fast reactors; Identification of important uncertainty parameters

Yamano, Hidemasa   ; Sakai, Takaaki; Kurisaka, Kenichi 

This study is aimed to develop a methodology of failure probability evaluation for the passive safety features. In this paper, the first step of this development is reported for both the passive shutdown and the decay heat removal systems, namely identification of failure causes on the passive safety features as well as identification of important uncertainty parameters for sensitivity analyses that will be performed in the subsequent step of this study. This paper describes the failure causes, ranking table, and identified important uncertain parameters.