Molecular Dynamics Simulation of Thermal Transport in UO2 Containing Uranium, Oxygen, and Fission-product Defects

The electricity from a light-water nuclear reactor ultimately comes from the heat emitted by fuel rods made of UO${}_{2}$. However, as fission products and defects build up in the urania, its effective thermal conductivity---and power output---changes, with potentially serious implications for reactor efficiency and safety. The authors develop a methodology to account for spin-phonon scattering, which is usually neglected in multiscale modeling of nuclear fuel. Their results are of interest both for reactor operation and for studying a much wider class of paramagnetic materials with antiferromagnetic transitions at low temperatures, including transition-metal oxides.