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

Abstract

COSMO-RS method was used in screening 2106 ionic liquids as alternate solvents to volatile ndodecane 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 BF 4 , 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.

Solvent Extraction of Cesium with a New Compound Calix[4]arene-bis[(4-methyl-1,2-phenylene)-crown-6]

“…26 It was catalyzed by cesium carbonate under refluxing in nitrogen atmosphere for 17 days. The resultant CalixBisMePhC shown in Figure 2 was then characterized by elementary analysis, 1 H NMR, and ESI-MS.…”

“…In the PUREX (plutonium uranium reduction extraction) process, both uranium and plutonium are recovered using the 30 % tri-n-butyl phosphate/kerosene extraction system. 1 Consequently, the process produces an acidic and highly radioactive solution, called high level liquid waste (HLW), containing fission, transuranic, and activation isotopes such as the long-lived minor actinides MAs(III), rare earth metals REs(III), heat generators Cs(I) and Sr(II), noble metals, Mo(VI), Tc(VII), Zr(IV), and so on. 1 Recovery of these metals is valuable to the safe disposal of HLW and a reduction in its potential risk to environment and human health.…”

“…1 Consequently, the process produces an acidic and highly radioactive solution, called high level liquid waste (HLW), containing fission, transuranic, and activation isotopes such as the long-lived minor actinides MAs(III), rare earth metals REs(III), heat generators Cs(I) and Sr(II), noble metals, Mo(VI), Tc(VII), Zr(IV), and so on. 1 Recovery of these metals is valuable to the safe disposal of HLW and a reduction in its potential risk to environment and human health. Although plenty of effort has been made, 2−13 industrial partitioning of these metals has been problematic so far.…”