Core design optimization for a novel heavy water moderated molten salt reactor

Abstract

BackgroundHeavy water moderated molten salt reactor (HWMSR) adopts heavy water as moderator and heavy metal elements dissolved in fluoride salt as the fuel, which has high neutron economy. But large temperature difference of fuel salt outlet will lead to the thermal fatigue of piping components at the top of the core.PurposeThis paper aims to optimize the core design of HWMSR to minimize the fuel salt outlet temperature.MethodsBy using the developed codes of neutron-thermal hydraulic coupling calculation and core critical search calculation, the power density distribution, outlet temperature distribution, initial 233U loading and breading ratio (BR) were analyzed for the cores with different size of molten salt channels.ResultsThe calculation results demonstrate that increasing the radius of molten salt channels in the inner core zone (correspondingly decreasing the radius of molten salt channels in the outer core zone) will decrease the peak of power density and the maximum outlet temperature of molten salt while the influence on BR and 233U initial loading.ConclusionsThis study provides a valuable foundation for core optimization of HWMSR.

Keywords

• hwmsr
• thermal hydraulic
• neutronics
• thorium-uranium fuel cycle