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

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

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.