An effect of gas expansion module on the inherent safety of the Korea advanced liquid metal reacotr

The safety characteristics of the gas expansion module (GEM) in the Korea Advanced LIquid MEtal Reactor (KALIMER) are investigated using the system analysis code, SSC-K. The GEMs are passively activated through a pressure change in response to a loss of flow and require no operator action or active systems. The resultant void in the GEMs near the core periphery increases neutron leakage and introduces significant negative reactivity. The accident initiator considered is a loss of flow with failure of scram (ULOF). Various analyses of multiple faults such as loss of heat sink, transient overpower, or failure of GEMs with the ULOF are performed. It was found that the KALIMER design has inherent safety characteristics and is capable of accommodating various types of ULOF. The self-regulation of power without scram is mainly attributed to the inherent and passive reactivity feedbacks in conjunction with the GEMs