The effect of insulation layer of KRUSTY on reactor power

BackgroundSmall modular reactor has the characteristics of simple structure, convenient construction and easy deployment. As a type of small modular reactor, the heat pipe reactor is usually operated in load following mode. Kilopower is a typical heat pipe reactor designed to provide 1 kW to 10 kW of electricity in space or on the surface of a planet or moon. As the prototype of the heat pipe reactor, the Kilowatt Reactor Using Stirling TechnologY (KRUSTY) has been tested and achieved satisfactory results.PurposeThis study aims to optimize the structure of KRUSTY, understand the influence of insulation layer on the reactor, and improve the efficiency of reactor output energy.MethodsFirstly, the multi-physics software Simscape was used as the system analysis tool, and the reactor power calculation module, heat pipe module and so on were added for the simulation of heat pipe reactor. Secondly, taking KURSTY as the object, the system models with six different insulation thickness schemes were built. Finally, the reactor behaviors under the conditions of 0.6 $ reactivity startup, ±4×10-4 reactivity introduction and ±50% load change were investiged, and the calculation results under different schemes were compared.ResultsComparison results show that the energy output efficiency of double thickness of Multilayer Insulation (MLI) scheme is the highest, reaching 79.71% with minimal the influence of each working condition on the energy output efficiency.ConclusionsThe results show that the efficiency of the reactor's energy output is higher when the number of gaps is increased between the core, the vacuum tank, the neutron reflector and other structures, and the vacuum tank contains a thick insulation layer.