Seismic probabilistic risk assessment method development for high temperature gas-cooled reactors

Sato, Hiroyuki  ; Nishida, Akemi  ; Ohashi, Hirofumi ; Muramatsu, Ken*; Muta, Hitoshi*; Matsuda, Kosuke*; Itoi, Tatsuya*; Takada, Tsuyoshi  ; Tanabe, Masayuki*; Yamamoto, Tsuyoshi*; Ikeda, Takao*

JAEA, in conjunction with Tokyo City University, The University of Tokyo and JGC Corporation have conducted development of a PRA method from October 2015 to March 2018 considering the safety and design features specific to HTGR. The primary objective of the project was to develop a seismic PRA method which enables to provide a reasonably complete identification of accident scenario including a loss of safety function in passive structures, systems and components. This presentation will provide the overview of the activities including development of a system analysis method for multiple failures, a component failure data using the operation and maintenance experience in the HTTR, seismic fragility evaluation method, and mechanistic source term evaluation method considering failures in core graphite components and reactor building. The presentation will also cover application results of developed methods to the risk analysis of a reference HTGR designed by JAEA.