Neutronics study of chloride fuel salts for experimental design of small Molten Salt Reactor

Abstract

From the Indian perspective, molten salt reactor technology is a promising option for thorium utilization in the third stage of the nation's nuclear programme. Recently, the physics design of a fluoride salt fuelled small molten salt reactor has been initiated as an experimental core to demonstrate the circulating fuel reactor technology. However, the literature suggests that chloride fuel salts have better breeding characteristics, particularly in fast-spectrum MSRs. The thermal-hydraulic and neutronics properties of the chloride fuel salts could considerably differ from that of fluoride. Therefore, the applicability of chloride fuel salts in a small MSR core has been investigated for the neutronics feasibility of the fuel type. In the study, criticality and safety parameters such as neutron multiplication factors and fuel temperature coefficient of reactivity are assessed for three options of chloride-based molten fuel salts. The predicted results for the experimental MSR thermal core fuelled with chloride-based fuel salts are reported in the paper. A brief review on the comparison of chloride fuel salts with the fluoride salts in MSR designs is also presented.