Safety design approach for a large-scale Japan Sodium-cooled Fast Reactor (JSFR)

Kotake, Shoji*; Yamano, Hidemasa   ; Sagayama, Yutaka 

The present paper describes safety goals and principles for Generation IV energy systems, with emphasis on prevention and mitigation against severe accidents in the safety design corresponding to Level 4 of the defense-indepth architecture. Consistent with them, a deterministic safety design approach has been applied to the Japan Sodium-cooled Fast Reactor (JSFR) with the complimentary use of probabilistic approach. The JSFR safety design principle has also been developed with safety design features corresponding to essential safety functions, such as reactor shutdown, decay heat removal and containment. Design principle against chemical activity of sodium is also discussed both on the isolation from the reactor core safety and the contribution to the plant reliability.