Multiphysics analysis of heat pipe cooled microreactor core with adjusted heat sink temperature for thermal stress reduction using OpenFOAM coupled with neutronics and heat pipe code

Heat-pipe-cooled microreactors (HPRs) have advantages such as a compact design, easy transportation, and improved system reliability stability. The core of an HPR consists fuel rods heat pipes in monolith, which is solid block structure containing many holes for the pipes. When designing HPR, high thermal stress reactivity feedback owing to expansion are important considerations. Therefore, high-fidelity multiphysics analysis tool required accurately analyzing core. performing analysis, it necessary couple pipe code, thermal-structural neutronics code. To develop tool, OpenFOAM, open source Computational Fluid Dynamics (CFD) ANLHTP, were coupled. In this process, structural solver OpenFOAM was verified, its limitations improved. confirm proper working mini-core problem analyzed using OpenFOAM-ANLHTP coupled Next, consider feedback, coupling with PRAGMA, GPU-based continuous-energy-Monte Carlo code performed, capability OpenFOAM-ANLHTP-PRAGMA confirmed through MegaPower reactor reduce temperature distribution within sink adjusted, reduced observed.