Comparison of neutronic behavior of UO2, (Th-233U)O2 and (Th-235U)O2 fuels in a typical heavy water reactor

The research carried out on thorium-based fuels indicates that these fuels can be considered as economic alternatives with improved physical properties and proliferation resistance issues.In the current study, neutronic assessment of UO2 in comparison with two (Th-233U)O2, and (Th-235U)O2 thorium-based fuel loads in a heavy water research reactor has been proposed.The obtained computational data showed both thorium-based fuels caused less negative temperature reactivity coefficients for the modeled research reactor in comparison with UO2 fuel loading. By contrast, 233U-containing thorium-based fuel and 235U-containing thorium-based fuel loadings in the thermal core did not drastically reduce the effective delayed neutron fractions and delayed neutron fractions compared to UO2 fuel. A provided higher conversion factor and lower transuranic production in the research core fed by the thorium-based fuels make the fuel favorable in achieving higher cycle length and less dangerous and costly nuclear disposals.