Computational chemical study on separation mechanism of Am from Cm with diamide-type ligands

Kaneko, Masashi   ; Watanabe, Masayuki   ; Suzuki, Hideya; Matsumura, Tatsuro  

Japan Atomic Energy Agency has developed separation reagents between Am and Cm ions, which are minor actinides, to achieve partitioning and transmutation strategy. We aim to elucidate the Am/Cm separation mechanism by various reagents at a molecular level to design a novel extraction reagent. This study focused on the Am/Cm separation with diglycolamide (DGA) and alkyl-diacetoamidamine (ADAAM) reagents by using density functional theory. We modeled the complex formation reactions by referring to reported single crystal structures and solvent extraction experiments. As the result, we succeeded in reproducing the Am/Cm separation behaviors with DGA and ADAAM reagents. Moreover, the electronic state analyses of the extracted complexes indicated that a difference in chemical bonding property of 5f-electrons between Am and Cm differentiates the Am/Cm selectivity.