Alpha-irradiation damage in CeO2, UO2and PuO2

Sintered pellets of CeO2 and UO2, as well as PuO2 powder, have been irradiated with alpha particles emitted from an effectively semi-infinite 238PuO2 source. The lattice parameters of all three materials increased with dose, Dα, according to the expression δa/a0 = A[1—exp(—BDα)], in agreement with a previously developed model. The recovery behavior of the lattice defects has been studied by isochronal annealing. Two recovery stages were observed in the temperature range between 50 and 1000°C for each material, and the activation energies were estimated based on previous single crystal studies. Comparisons with self-damage from alpha decay are made, and the behavior of the lattice defects is discussed.