外部ハザード重畳時の確率論的リスク評価手法の研究開発; 高速炉の空気冷却崩壊熱除去系への影響形態に基づく同定

Research and development of probabilistic risk assessment methodology of external hazard combinations; Identification of hazard combinations in terms of impacts on SFR air cooling decay heat removal system

岡野 靖; 山野 秀将   ; 高田 孝  ; 西野 裕之  ; 栗坂 健一 

Okano, Yasushi; Yamano, Hidemasa; Takata, Takashi; Nishino, Hiroyuki; Kurisaka, Kenichi

高速炉は大気を最終除熱源とし、気象等の外部ハザードが崩壊熱除去系に影響を及ぼし得る。頻度は稀だが影響の大きな未曾有の外部ハザードの後、発現し得る頻度の別の外部ハザードが重畳した場合に、崩壊熱除去系への影響の強度及び継続時間から、考慮すべきハザードの重畳と定量化すべき事項を同定した。

External hazard related to meteorological phenomena may impact on decay heat removal system using ambient air as an ultimate heat sink such as in sodium-cooled fast reactor system. This study identify the combination of external hazards to be considered and the items to be quantified for probabilistic risk assessment from the view point of strength and affecting duration of the hazard in case that secondary external hazard which has predicted appearance frequency overlaps after an primary external hazard which is very rare but high consequence.