Preliminary evaluation of JSFR achievement level to risk targets

Kurisaka, Kenichi ; Okamura, Shigeki*

Japan Atomic Energy Agency (JAEA) has been developing the Japan Sodium-cooled Fast Reactor (JSFR) in the Fast Reactor Cycle Technology Development (FaCT) Project. Risk targets were set out as part of the safety-related design requirement: i.e., the quantitative safety design requirements on the core damage frequency (CDF) and the containment failure frequency (CFF). This paper describes a preliminary evaluation of achievement level of JSFR to the risk targets at the FaCT project phase-I: JFY2006 to JFY2010. A Level-1 PSA has been implemented preliminarily to evaluate the CDF related to internal initiators in power operation. The calculated CDF became lower than the both requirements on CDF and CFF. For seismic events, the seismic fragility of principal structures and components was evaluated in terms of core damage prevention. This evaluation was based on the seismic response analysis, which considered the seismic isolation effect and the hardening effect of the laminated rubber bearing in the isolation devices. As a result, we confirmed that the principal structures and components of JSFR have sufficient seismic margin. Based on this, we judged the risk target could be achieved against the seismic event.