Trends in the energetics and defect clustering tendencies for UO2 compounds substituted with trivalent rare earth cations (M3+) are investigated computationally using methods based on density functional theory. Higher energetic stability of U1-xMxO2-0.5x solid solutions relative to constituent oxides and increased preference for higher oxygen coordination around the trivalent cation are found with increasing size of the M3+ species. The implications of the computational results for the effect of trivalent fission products on oxygen ion mobility in spent fuel are discussed.
ASJC Scopus subject areas
- Nuclear and High Energy Physics
- Materials Science(all)
- Nuclear Energy and Engineering