A snapshot review on uranyl secondary phases formation in aqueous systems

Abstract Irradiated fuel based on UO 2 is expected to be disposed of in an underground repository according a “once-through” cycle policy. In addition, those countries that have chosen reprocessing their irradiated will also need this kind repository. There international consensus option as the best dispose properly high-level waste. multiple-barrier concept repository, pellet first barrier release fission products (FP) environment. Nevertheless, after storage times several thousand years, it foreseen groundwater penetrate and infiltrate emplacement, eventually interact with spent fuel. Upon contact both, matrix FP might released. Because water radiolysis, uranium oxidized from its tetravalent state hexavalent uranyl ion, being known far more soluble than (IV). Then, during oxidative-dissolution depending surface/volume ratio, secondary phases (containing 2+ ) precipitate at whole pH range. These play essential role radionuclide final disposal environment due capacity seize trace radioelements, therefore, reduce radionuclides mobility. Some important can into inner solid structure. Here, we examine state-of-the-knowledge advances potentially formed under relevant conditions. An overview likely compounds conditions, well progress made concerning experimental data field presented. Graphical abstract