Molecular dynamics simulation study of soluble fission products impact on MOX fuel thermodynamic properties

The impact of soluble fission products, Ce, Gd, La, Nd, and Zr, on the thermodynamic properties of the mixed oxide (MOX) fuel was investigated. Molecular dynamics simulations were carried out to compute the lattice parameters, linear thermal expansion coefficient, and heat capacity of systems of which composition can be considered as representative of irradiated MOX fuel. The introduction of trivalent cations showed a more significant effect on heat capacity than the one of tetravalent cations, highlighting the importance to take into account these elements to evaluate MOX fuel properties, especially at high temperatures where experimental data are not available.