Development of the Chalmers Grouped Actinide Extraction Process

Abstract

Abstract. Several solvents for Grouped ActiNide EXtraction (GANEX) processes have been investigated at Chalmers University of Technology in recent years. Four different GANEX solvents; cyclo-GANEX (CyMe 4 --BTBP, 30 vol.% tri-butyl phosphate (TBP) and cyclohexanone), DEHBA-GANEX (CyMe 4 -BTBP, 20 vol.% N,N-di-2(ethylhexyl) butyramide (DEHBA) and cyclohexanone), hexanol-GANEX (CyMe 4 -BTBP, 30 vol.% TBP and hexanol) and FS-13-GANEX (CyMe 4 -BTBP, 30 vol.% TBP and phenyl trifl uoromethyl sulfone (FS-13)) have been studied and the results are discussed and compared in this work. The cyclohexanone based solvents show fast and high extraction of the actinides but a somewhat poor diluent stability in contact with the acidic aqueous phase. FS-13-GANEX display high separation factors between the actinides and lanthanides and a good radiolytic and hydrolytic stability. However, the distribution ratios of the actinides are lower, compared to the cyclohexanone based solvents. The hexanol-GANEX is a cheap solvent system using a rather stable diluent but the actinide extraction is, however, comparatively low.

On the Basic Extraction Properties of a Phenyl Trifluoromethyl Sulfone-Based GANEX System Containing CyMe4-BTBP and TBP

“…Comparing these distribution ratios with previously investigated GANEX systems using other diluents, it is found that the values are found to be in a similar order of magnitude. [30][31][32] Desirable distribution ratios should render a high metal extraction, while still maintaining a feasible actinide stripping. Neptunium has a rather low distribution ratio, and therefore further investigations are needed to successfully extract neptunium together with the other actinides in this system.…”

Stability of Different BTBP and BTPhen Extracting or Masking Compounds against γ Radiation

“…As an example, F-3 ( meta -nitrobenzotrifluoride) or FS-13 (phenyltrifluoromethylsulfone)aromatic polar diluents with low viscosity, high density, and good chemical stabilitymay be listed. In addition to other advantages, their high density ensures good phase separation during metal extraction . A new group of these polar fluorinated diluents includes carbonates of fluorinated alcohols, for example, BK-1 (carbonate of 2,2,3,3-tetrafluoropropan-1-ol; Table ) or BK-2 (carbonate of 2,2,3,3,4,4,5,5-octafluoropentan-1-ol) .…”

Homogenous recycling of transuranium elements from irradiated fast reactor fuel by the EURO-GANEX solvent extraction process

“…The co-recovery of minor actinides is incorporated by introducing a second extracting agent that shows high selectivity for the minor actinides over FPs, including chemically similar lanthanides. For example, the CHALMEX concept [7][8][9] uses a solvent containing CyMe 4 -BTBP (6,6′bis(5,5,8,8-tetramethyl-5,6,7,8-tetrahydro-benzo-1,2,4-triazin-3-yl)-2,2′-bipyridine, Figure 1) [10][11] plus TBP dissolved in a polar diluent such as cyclohexanone or FS-13 (phenyl trifluoromethyl sulfone) to directly extract only U and TRU from dissolved fuel solutions. The chemical system has promise but so far has not been tested in a counter-current flow-sheet trial.…”