Computational screening of ionic liquids as solvents for reprocessing of spent nuclear fuel

COSMO-RS method was used in screening 2106 ionic liquids as alternate solvents to volatile n-dodecane used in PUREX. The distribution coefficients of uranylnitrate in ionic liquids/aqueous nitric acid biphasic system and the solubility of the ionic liquids in water were determined using COSMO-RS. Seventeen ionic liquids based on tetrafluoroborate BF4, were the most hydrophobic than others screened with hexamethylguanidiumtetrafluoroborate having the highest distribution coefficient. Their distribution coefficients were higher than that of the convention n-dodecane used for separation of uranium and plutonium from spent nuclear fuel but having more hydrophilicity than n-dodecane. This shows that ionic liquids can be used as alternate solvents in PUREX.