The MMG focuses on problems within nuclear reactors related to its fuel and how heat is transferred inside the reactor. "Fuel degradation" refers to how uranium pellets and the rods they are encased in (several rods bundled together is what makes a "fuel assembly") eventually wear out over time due to high heat and irradiation inside a reactor. The group states three main objectives: "The mission of the MMG is to support the INL goal to advance the U.S. nuclear energy endeavor by: