​What is Marmot?

Marmot is the mesoscale fuel performance code under development as part of the US DOE Nuclear Energy Advanced Modeling and Simulation Program. The purpose of Marmot is to predict the coevolution of microstructure and material properties of nuclear fuels and claddings due to stress, temperature, and irradiation damage, and to supply microstructure-based materials models to engineering scale fuel performance modeling code such as BISON.


How does Marmot work?

Marmot solves the phase field equations coupled to solid mechanics and heat conduction using the finite element method. Marmot is based on the Multiphysics Object-Oriented Simulation Environment (MOOSE), and much of its basic capability in the areas of the phase field method, mechanics, and heat conduction comes directly from MOOSE modules. The Marmot repository contains export-controlled code, such as nuclear specific material models.


Marmot grain growth simulation of a reconstructed microstructure taken from HEDM data of UO2. Left: reconstructed experimental microstructure, right: sample with observable grain growth after simulated annealing.


The calculated temperature profile across a reconstructed 3D fuel sample containing metallic precipitates.