Separation of Spent Nuclear Fuel: Minor Actinide and Palladium Extraction by Heterocyclic Diamides

The extraction properties of a series of diamides of 2,2-bipyridine-6,6-dicarboxylic acids with respect to americium, curium, neptunium, thorium, light lanthanides and a series of d-elements present in solutions of highly radioactive wastes have been studied in this work. It has been shown that the extraction properties of diamides are determined not only by the structure of the heterocyclic framework, but also by the nature of substituents in positions remote from oxygen centers. The influence of substituents in a series of extractants is determined by differences in their electronic nature, and also depends on their volume and position. In the work, effective and selective extractants were found for the separation of the Am/Eu pair (SF up to 27), and fundamental patterns were revealed between the structure of the extractant and the efficiency of extracting metal ions.