CFD analysis for asymmetric power generation in a prismatic fuel block of fluoride-salt-cooled high-temperature test reactor

The Fluoride-salt-cooled High-temperature Reactor (FHR) is an advanced reactor concept that uses TRISO high temperature fuel and low-pressure liquid salt coolant. A 20 MWth Test reactor version (FHTR), as the key step in demonstrating the technical feasibility, is currently under design at Massachusetts Institute of Technology. The temperature distribution is analyzed in this study using a CFD software, CD-adapco STARCCM+. A unit-cell with one coolant channel and six one-third fuel compacts is with coupled conduction and convection heat transfer. The model is validated by theory for developing laminar flow in the benchmark study with excellent agreement. Azimuthal distributions of Temperature, heat flux, and heat transfer coefficient along coolant-graphite interface were obtained for various scenarios with asymmetric heat source and graphite materials. The results show that the asymmetric power generation has little impact on peak fuel temperature, interface temperature, and heat transfer coefficient for a unit-cell module due to effective thermal conduction of graphite matrix.