Prismatic High Temperature Gas-Cooled Reactor Model in Support of Integrated Energy Systems

A prismatic high temperature gas-cooled reactor (HTGR) model was developed in the Modelica
language for the Idaho National Laboratories (INL) HYBRID repository, which is a part of INL’s
Framework for Optimization of ResourCes and Economics (FORCE) toolset. The model is based
on Ultra Safe Nuclear Corporation’s MMR 5 design, which is a 15 MWt TRISO fueled prismatic
HTGR using helium as the primary coolant. This is a multi-physics model with 1D thermal
hydraulics and point kinetic neutronics and is able to simulate the dynamic respond to feedback
using a point kinetics model. The reactor model was able to stabilize after around 100 minutes after
a 200pcm reactivity insertion event. The model can also be connected to other models from the
HYBRID repository to simulate a wide variety of energy systems.