Phonon dynamics of UO$_{2}$ at high temperature

Inelastic neutron scattering and numerical simulations are being used to investigate the fundamental aspects of phonons and thermal transport in UO2 as part of a DOE-EFRC ``Center for Materials Science of Nuclear Fuel'' project. Understanding thermal transport associated with nuclear fuel environments requires a correct accounting for a wide range of phonon scattering processes, including anharmonic phonon-phonon, phonon-fission product, and phonon-defect cluster. Reactor and spallation neutron measurements of phonon dispersion, phonon linewidths and density of states in UO$_{2}$ at room and high temperature are in progress for direct comparison with atomic potential lattice-dynamics simulations of phonon dispersion, phonon group velocity, phonon linewidth, and phonon density of states. Direct comparisons between experimental measurements and numerical simulations in UO$_{2}$ as a function of temperature will be presented.