Conceptual design and analysis of a multipurpose micro nuclear reactor power source

Micro Heat Pipe-cooled Reactor (HPR) power source is featured with lower noise level, higher power output, longer lifetime than conventional power sources. It could be applied for the energy system of space or underwater vehicles. The HPR power source is considered as an ideal candidate for the space and underwater reactor concept. In this paper, a 120 kWe lithium HPR power source applied for multiple use is neutronics designed. Uranium nitride fuel with 70% enrichment and lithium heat pipe are adopted in the reactor core. Tungsten and water are used as shields on both sides of the core. The reactivity is controlled by 6 control drums with B₄C neutron absorbers. Monte Carlo code MCNP is used to obtain kinetics parameters, the power distribution, shield analysis, reactivity coefficient and core criticality safety. A code MCORE coupling MCNP and ORIGEN is used to analysis the fuel depletion characteristics of the designed reactor core. A 14-year once-through fuel cycle is adopted according to optimization analysis. Overall, the designed core parameters preliminary satisfy the safety requirements and the rector is neutronics safe. This work provides reference to the design and application of the micro nuclear power source.