Origin of Low Thermal Conductivity in Nuclear Fuels

Quan Yin, Sergey Y. Savrasov
2008 Physical Review Letters  
Using a novel many-body approach, we report lattice dynamical properties of UO2 and PuO2 and uncover various contributions to their thermal conductivities. Via calculated Grueneisen constants, we show that only longitudinal acoustic modes having large phonon group velocities are efficient heat carriers. Despite the fact that some optical modes also show their velocities which are extremely large, they do not participate in the heat transfer due to their unusual anharmonicity. Ways to improve
more » ... Ways to improve thermal conductivity in these materials are discussed.
doi:10.1103/physrevlett.100.225504 pmid:18643431 fatcat:gkucyryapfgeradxbhx5mqtd2i