Selective separation of Am(III) from PUREX Raffinate with a TODGA-based solvent using innovative hydrophilic complexing agents

Americium is the main contributor to the long-term radiotoxicity and to the heat generation of glasses used for HLW conditioning. To decrease these impacts and to avoid the difficult recycling of curium, the selective separation and recovery of a pure americium product directly from PUREX raffinate is envisaged in this study. The new approach is based on the co-extraction of lanthanide(III) and actinide(III) cations from a PUREX raffinate into an organic phase containing N,N,N',N'tetraoctyl-diglycolamide (TODGA) as extractant, followed by the subsequent selective stripping of Am(III) and separation from Cm(III) and lanthanides. Three water-soluble selective ligands were studied: H4TPAEN developed at the CEA Marcoule, TS-BTPhen developed at the University of Reading, and SO3-Ph-BTBP developed at KIT. Very promising results were achieved for all systems with a quite high Cm(III)/Am(III) selectivity between 3-4 to carry out the difficult separation at reasonably high process relevant nitric acid acidities. Numerous batch experimental data were acquired for the development of the extraction model. Finally, tests on single centrifugal contactors were conducted to get information on the kinetic and hydraulic performance of the system. Finally, tests on single centrifugal contactors were conducted to get information on the kinetic and hydraulic performance of the system.