Water on Actinide Dioxide Surfaces: A Review of Recent Progress.

The fluorite structured actinide dioxides (AnO₂), especially UO₂, are the most common nuclear fuel materials. A comprehensive understanding of their surface chemistry is critical because of its relevance to the safe handling, usage, and storage of nuclear fuels. Because of the ubiquitous nature of water (H₂O), its interaction with AnO₂ has attracted significant attention for its significance in studies of nuclear fuels corrosion and the long-term storage of nuclear wastes. The last few years have seen extensive experimental and theoretical studies on the H₂O–AnO₂ interaction. Herein, we present a brief review of recent advances in this area. We focus on the atomic structures of AnO₂ surfaces, the surface energies, surface oxygen vacancies, their influence on the oxidation states of actinide atoms, and the adsorption and reactions of H₂O on stoichiometric and reduced AnO₂ surfaces. Finally, a summary and outlook of future studies on surface chemistry of AnO₂ are given. We intend for this review to encourage broader interests and further studies on AnO₂ surfaces. [ABSTRACT FROM AUTHOR]