Advanced sodium-cooled fast reactor development regarding GIF safety design criteria

Design studies on a next generation sodium-cooled fast reactor (SFR) considering the safety design criteria (SDC) developed in the generation IV international forum (GIF) was summarized. To meet SDC including the lessons learned from TEPCO's Fukushima Dai-ichi nuclear power plants (1F) accident, the heat removal function was enhanced to avoid loss of the heat removal function even if any internal events exceeding design basis or severe external events happen. Several design options for alternative decay heat removal systems have been investigated. An auxiliary core cooling system using air as ultimate heat sink has been selected as an additional cooling system regarding system reliability and diversification. Even though the advanced SFR already adopts seismic isolation system, main component designs have been improved considering revised earthquake conditions. For other external events, design measures for various external events are taken into account. Reactor building design has been improved and important safety components are diversified and located separately to improve independency. Design studies and evaluations on the advanced sodium-cooled fast reactor have contributed to the development of safety design guidelines (SDG) which is under discussion in the GIF framework. (author)