Batch Tests for Optimisation of Solvent Composition and Process Flexibility of the CHALMEX FS-13 Process

Abstract

Studies have been performed with the purpose of determining the optimal solvent composition of a Chalmers grouped actinide extraction (CHALMEX) solvent for the selective coextraction of transuranic elements in a novel Grouped ActiNide EXtraction (GANEX) process. The solvent is composed of 6,6'-bis(5,5,8,8-tetramethyl-5,6,7,8-tetrahydro-benzo-[1,2,4]triazin-3-yl)-[2,2']-bipyridine (CyMe 4-BTBP) and tri-n-butyl phosphate (TBP) in phenyl trifluoromethyl sulfone (FS-13). The performance of the system has been shown to significantly depend on the ratios of the two extracting agents and the diluent to one another. Furthermore, the performance of the determined optimal solvent (10 mM CyMe 4-BTBP in 30% v/v TBP and 70% v/v FS-13) on various simulated PUREX raffinate solutions was tested. It was found that the solvent extracts all transuranic elements with high efficiency and good selectivity with regard to most other elements (fission products/activation products) present in the simulated PUREX raffinate solutions. Moreover, the solvent was found to extract a significant amount of acid. Palladium, silver, and cadmium were co-extracted along with the TRUradionuclides, which has also been observed in other similar CHALMEX systems. The extraction of plutonium and uranium was preserved for all tested simulated PUREX raffinate solutions compared to experiments using trace amounts.

Gamma radiolytic stability of the novel modified diglycolamide 2,2′-oxybis(N,N-didecylpropanamide) (mTDDGA) for grouped actinide extraction

“…[12][13][14][15] The CHALMEX process, developed by Chalmers University, uses a route based on a direct actinide co-extraction by 6,6 0 -bis(5,5,8,8-tetramethyl-5,6,7,8-tetrahydrobenzol-[1,2,4]-triazin-3-yl) [2,2]bipyridine (CyMe 4 -BTBP) and tri-n-butyl phosphate (TBP) in phenyl tri-uoromethyl sulfone (FS-13), for which elaborate solvent composition optimization has been conducted. [15][16][17][18][19][20][21] The current formulation of the EURO-GANEX process makes use of two extractants in odorless kerosene to rst extract both the actinides and the lanthanides into the organic phase. [22][23][24] For this rst co-extraction, a solvent comprising 0.5 mol L À1 DMDOHEMA and 0.2 mol L À1 N,N,N 0 ,N 0 -tetra-n-octyldiglycolamide (TODGA) was used.…”

“…12–15 The CHALMEX process, developed by Chalmers University, uses a route based on a direct actinide co-extraction by 6,6′-bis(5,5,8,8-tetramethyl-5,6,7,8-tetrahydrobenzol-[1,2,4]-triazin-3-yl)[2,2]bipyridine (CyMe 4 –BTBP) and tri- n -butyl phosphate (TBP) in phenyl trifluoromethyl sulfone (FS-13), for which elaborate solvent composition optimization has been conducted. 15–21…”