Separation of Americium from Curium through Oxidation State Control with Record Efficiency

Separation of americium (Am) from curium (Cm) could greatly facilitate the development of advanced nuclear fuel cycles, help with accurate nuclear forensic analysis, and allow for more efficient recovery and utilization of the two strategic elements. In this work, an Am/Cm separation strategy based on the stabilization of pentavalent Am in a biphasic solvent extraction system using bismuthate as the oxidant and N,N,N',N'-tetraoctyl diglycolamide (TODGA) as the extractant was developed. The distinctive differences between Am(V) and Cm(III) in terms of both steric configuration and charge density afford record high Cm/Am separation factors (>10⁴) through only one single contact in solvent extraction. This separation strategy possesses superior features including fast kinetics, long-time stability, no secondary solid radioactive waste generation, and applicability over a wide range of HNO₃ acidities, making it promising for Am/Cm separation and analysis in a variety of applications.