Neutronic evaluations for MNSR research reactor core conversion from HEU to LEU

We studied enrichment reduction evaluations for Iranian Miniature Neutron Source Reactor (MNSR) preserving prior reactivity limitations. Utilization of high density Low Enriched Uranium (LEU) fuels such as UO2, U3Si2 and U9Mo have been addressed from neutronics point of view.The Monte Carlo code MCNP4C has been used for studying the reactor core neutronic parameters. The feasibility of candidate LEU fuels have been validated via the MNSR reference fuel parameters.The results show that the average neutron flux in irradiation channels of LEU core configurations is reduce within 7%. According to the calculated reactivity parameters and thermal neutron flux in irradiation channels, this reduction would not affect the reactor safety as well as its applicability.

► Neutronic evaluations for Iranian MNSR core conversion from HEU to LEU have been performed. ► The core neutronic parameters have been calculated using the MCNP4C code. ► Calculations have been validated using the MNSR reference fuel parameters. ► The average neutron flux of LEU core configurations is reduced within 7%.