「常陽」における確率論的安全評価,4-2; 「常陽」UTOP事象の炉心損傷事象推移評価

Probabilistic safety assessment on the experimental fast reactor JOYO, 4-2; Assessment of the event progression of core disruption during UTOP event in JOYO

飛田 吉春; 佐藤 一憲 ; 川田 賢一   ; 深野 義隆  

Tobita, Yoshiharu; Sato, Ikken; Kawada, Kenichi; Fukano, Yoshitaka

「常陽」に対して評価された炉心損傷カテゴリーのうち、リスク評価上の重要度が大きいと評価されたUTOP(Unprotected Transient Overpower)事象について炉心損傷の事象推移を評価した。初期過程では出力バーストが生じないことを確認し、損傷拡大の過程においても厳しい出力バーストには至りにくいとの結果を得た。

The event progression of core disruption in UTOP (Unprotected Transient Overpower), which was judged to be an important core disruption category in risk assessment of JOYO, was analyzed. It was confirmed that power burst did not occur in the initial phase of the accident and was not likely to occur in the successive phase of disruption extension.