Stability studies of the SO3-Ph-BTBP under AmSel process conditions

• Assessment of stability of SO3-Ph-BTBP in the AmSel process. • SO3-Ph-BTBP concentration quantification after irradiation by Raman Spectroscopy. • Better Am/Cm separation when SO3-Ph-BTBP is irradiated with an organic phase. • Negligible SO3-Ph-BTBP degradation under AmSel process conditions. The separation of Am from Cm in irradiated nuclear fuel remains a significant challenge for the future of nuclear fuel reprocessing. Among emerging hydrometallurgical processes, the AmSel process shows promise by employing two molecules with inverse selectivity: the very well-known TODGA, in the organic phase; and the SO 3 -Ph-BTBP in the aqueous phase. In this novel study, the radiolytic stability of SO 3 -Ph-BTBP is evaluated in detail using Quantitative Raman Spectroscopy to predict its behaviour and stability from fundamental to process operation conditions. The outcomes of this work allow to indicate that SO 3 -Ph-BTBP exhibits enhanced stability when the aqueous phase is irradiated in contact with the organic phase, while the presence of metals has minimal impact on stability. Nevertheless, under more realistic conditions, the combination of both factors synergistically leads to a negligible degradation, highlighting the robustness of SO 3 -Ph-BTBP for its application under AmSel process conditions.