Coupled multiphysics multiscale transient simulations of the Mk1-FHR reactor using finite volume capabilities of the MOOSE framework

Multiphysics simulations are key to reactor safety analysis, especially for novel reactor designs lacking experimental data. Simulation tools within the multiphysics object-oriented simulation environment (MOOSE) framework, such as the Griffin reactor physics application and the coarse mesh computational fluid dynamics solver Pronghorn, can be coupled to perform such multiphysics transient simulations. We feature those capabilities in tightly-coupled multiphysics transient simulations of a simplified Mk1 pebble bed fluoride-salt-cooled high temperature (PB-FHR) reactor. A porous media model based on the incompressible Navier Stokes equation was implemented using the finite volume method for this work. This leverages the newly implemented finite volume discretization feature in MOOSE. (authors)