Neutronic and burnup characteristics of potential dual‐cooled annular ( <scp> Th‐ ²³³ U‐ ²³⁵ U </scp> ) <scp> O ₂ </scp> fuel for the advanced pressurized water reactors: An assembly‐level analysis

Abstract

Many efforts are now being made to ensure nuclear power plant safety and efficiency. One of these is the use of dual-cooled annular fuel, which is an internally and externally cooled annular fuel with many advantages in heat transfer characteristics and neutron thermalization. Another is the tendency to use thorium-containing fuel to extend the fuel cycle and reduce plutonium production. Hence, in this study, the performance of dual-cooled annular fuel fueled by a new suggested thorium-based fuel, namely (Th-233U-235U)O2, has been presented and investigated from a neutronic point of view in an AP1000 reactor assembly. The neutronic and safety properties of the envisaged dual-cooled annular assemblies are compared to those of two hypothetical reference assemblies fueled with UO2 and (Th-233U)O2. The primary neutronic goal is to achieve a longer cycle length than the proposed reference assemblies while retaining or improving safety parameters over the reference assemblies. The obtained results show that the studied dual-cooled annular assemblies have a longer criticality period than the reference designs. Other safety parameters, such as the power peaking factor, the delayed neutron fraction, and the moderator and fuel temperature coefficients, demonstrate that dual-cooled annular assemblies have favorable safety parameters compared to UO2 or (Th-233U)O2. However, this analysis would benefit from a more detailed burnup simulation based on a full core modeling, as well as a comprehensive thermal-hydraulic analysis in conjunction with a neutronic analysis.