Structural Chemistry of Solid Solutions in the UO₂-Gd₂O₃ System

The percent theoretical density, lattice parameter, oxygen-to-uranium ratio, and thermal conductivity of UO₂-Gd₂O₃ burnable absorber fuel pellets were analyzed in terms of the structural chemistry of the cubic fluorite lattice and the chemical behavior of various uranium cations. The sinterability of gadolinia-containing fuel pellets enabled an interpretation to be made of the possible structural models adopted in the system, depending on the sintering conditions.