Core coolability following loss-of-heat sink accidents

Most investigations of core meltdown scenarios in liquid metal fast breeder reactors (LMFBRs) have focused on accidents resulting from unprotected transients. In comparison, protected accidents which may lead to loss of core coolability and subsequent meltdown have received considerably less attention until recently. The sequence of events leading to the protected loss-of-heat sink (LOHS) accident is among other things dependent on plant type and design. The situation is vastly different in pool-type LMFBRs as compared to the loop-type design; this is as a result of major differences in the primary system configuration, coolant inventory and the structural design. The principal aim of the present paper is to address LOHS accidents in a loop-type LMFBR in regard to physical sequences of events which could lead to loss-of-core coolability and subsequent meltdown