Design Evolutions of the Molten Salt Fast Reactor

CNRS has focused R&D efforts on the development of a new reactor concept called the Molten Salt Fast Reactor (MSFR), characterized by a circulating liquid fuel and a fast neutron spectrum. This paper presents the new design proposed for the fuel circuit in the frame of the SAMOFAR European project and focuses on the design studies of the emergency draining system of the MSFR. These new designs result from physical and preliminary safety studies such as optimizing the use of the molten salt both as fuel and coolant, defining the operating procedures or minimizing the fuel leakage risks. Additional requirements are considered for the emergency draining system to be able to confine the fuel and to evacuate the residual heat over very long time periods (months) with no human intervention and to guaranty that under no circumstance the salt may reach criticality in this area. (author)