Résumé
The radiolytic generation of hydrogen peroxide plays a crucial role in actinide (An) chemistry, influencing the structural evolution of An compounds and introducing novel bonding characteristics. In particular, nanoscale uranyl clusters and peroxide precipitates such as studtite and metastudtite have been implicated in the corrosion and dissolution of UO₂-based materials, potentially enhancing radionuclide release. While hexavalent uranyl peroxides have been extensively studied, investigations into other actinide peroxides, particularly tetravalent ones, remain particularly scarce. This proposal focuses the structural and electronic properties of tetravalent peroxides (Th, Pu) under environmentally relevant conditions.