Rouhollah (Kouroush) Gheisari

Research reactors are designed for testing of the scattering, transport, and activation of neutrons, non-destructive testing of structural elements of the heart, and the training of specialized manpower based on thermonuclear calculations. In the present study, the neutron calculations of the UTRS-1J training reactor core have been evaluated using the Monte Carlo statistical method and the MCNPX2.6.0 neutron transport code based on the proposed model for the arrangement of hexagonal fuel complexes. In the modeling of the new reactor core, preservation of the basic parameters of the reference core design is postulated, and only the structure of the fuel complexes was changed from square to hexagonal. Neutronic calculations were performed, including the calculation of the effective proliferation factor of the core, the neutron flux of the thermal group in the radial and axial direction of the core, and the fuel consumption calculations in the reactor equilibrium cycle and in the CZP state.The results show that the arrangement of the radial profile of the fuel with the hexagonal complexes has caused safety in the design range.Also, the non-fluctuation of the reactor power distribution is observed in the axial direction. Reactor fuel consumption with hexagonal complexes during the operation cycle has increased efficiency, reduced costs in safe conditions and increased burnup, and as a result we will have optimal performance with more fissile mass. Evaluations suggest that the proposed makeup for the radial profile of fuel with hexagonal complexes can be implemented safely to improve the performance of the UTRS-1J reactor within safe limits without making major changes to the reactor systems.