Thermohydraulic Performance in SMR Reactors with Mixed Oxide (U, Th)O2 Fuel: A Computational Approach

This paper presents a computational study on the thermohydraulic performance of subchannels within Small Modular Reactor (SMR) configurations using Mixed Oxide (MOX) fuels comprising (U, Th)O2 alongside subchannels containing conventional UO2. The research aims to evaluate these fuel types operational efficiency and safety within the context of small-scale reactors. Utilizing a Computational Fluid Dynamics (CFD) model implemented in OpenFOAM, this study considers the variability of the thermophysical properties of the materials as influenced by temperature changes. The findings reveal that MOX fuels exhibit lower maximum temperatures than UO2, suggesting a more uniform radial temperature distribution. Moreover, both the cladding and coolant temperatures remain within safe operational limits across all scenarios examined, highlighting the potential of MOX fuels to enhance the safety and efficiency of SMRs. This analysis advances our understanding of the thermal behavior of advanced fuel compositions in nuclear reactors. It underscores the importance of comprehensive thermohydraulic studies in the design and operation of next-generation nuclear power systems.