Development of 3-dimensional seismic isolation system for sodium-cooled fast reactor

Na冷却高速炉に適用する3次元免震装置の開発

山本 智彦  ; 深沢 剛司*; 内田 昌人*; 岡村 茂樹*; 藤田 聡*

Yamamoto, Tomohiko; Fukasawa, Tsuyoshi*; Uchita, Masato*; Okamura, Shigeki*; Fujita, Satoshi*

Na冷却高速炉は、高温かつ低圧で運転するため、原子炉機器等は薄肉構造を採用しているが、薄肉構造は耐震上不利となるため、水平免震構造の適用を検討してきた。しかしながら、原子炉の大出力化を考慮すると、水平のみならず上下の地震動の低減する必要があるため、従来検討してきた水平免震装置をベースに上下方向の地震動低減効果が期待できる3次元免震装置の開発を実施している。本報告では、本研究で提案する3次元免震装置の概要と各機器の要素試験と地震応答解析結果について述べる。

A sodium-cooled fast reactor (SFR) is operated at a high temperature and a low pressure. Components for the SFR have been designed as thin-wall structure to mitigate the thermal stress due to the operation at a high temperature. However, thin wall structures have a disadvantage of the structural integrity for earthquake. To avoid this disadvantage, SFR will adopt seismic isolation system to reduce horizontal seismic loads. Also, it is important to reduce not only the horizontal seismic response but also the vertical seismic response in order to secure the structural integrity of components for the SFR and to realize high power by upsizing of the reactor vessel. To realize these requirements, the 3-dimensional seismic isolation system for the SFR had been studied. This paper describes the concept of the 3-dimensinal seismic isolation system and isolation performance obtained by the seismic response analysis.