Cooling Study of the Reflector Tank of a SMR Reactor Through Conjugate Heat Transfer

Abstract

Small Modular Reactors (SMR), with a power below 300 MWe according to the IAEA, offer a promising solution to climate change due to their rapid deployment and lower cost. A key component of SMRs is the radial reflector surrounding the core, which improves neutron efficiency and protects the reactor vessel from irradiation, while preventing coolant flow bypass. However, its proximity to the core leads to heating from gamma radiation, requiring proper cooling. This work presents a methodology to evaluate the three-dimensional temperature field of an SMR reflector using Conjugate Heat Transfer (CHT) and Computational Fluid Dynamics (CFD) with OpenFOAM. Maximum temperatures under full power conditions were verified through coupled fluid-solid simulations, starting with a single channel and extending to a 1/6 scale model of the reflector. The results highlight the importance of considering the axial temperature profile in the cooling channels for solid calculations, developing a suitable methodology for thermal-hydraulic analysis of reflectors in SMRs.