Fission product interactions with nitrogen donor ligands used for spent nuclear fuel treatment

The structures of CyMe4-BTBP complexes of americium(iii) and europium(iii) in solvents used in solvent extraction, explaining their separation properties

“…The structure around the absorbing atom in the dicomplexes of 6,6'-bis (5,5,8,8-tetramethyl-5,6,7,8-tetrahydro-benzo [1,2,4]triazin-3-yl) [2,2]bipyridine, CyMe4-BTBP, with americium(III) and europium(III) have been determined by means of Am and Eu L3 edge EXAFS spectroscopy in a series of solvents used to separate these metal ions using solvent extraction. The obtained structural information has been correlated with previously reported solubility and selectivity data as well as ionic radii in general terms.…”

“…1 Today the utilisation of nuclear power is an effective way to produce electricity with very low emission of greenhouse gases, 2 which has increased the interest for the technique. However, a concern with nuclear power is the production of highly radioactive used nuclear fuel (UNF).…”

“…Recent studies have shown that poly-aromatic nitrogen compounds, N-PAHs, acting as tetradentate chelating ligands to the metal ions in the extraction, have the ability to sufficiently separate An(III) from Ln(III). [7][8][9][10] One of these N-PAHs, 6,6'-bis (5,5,8,8-tetramethyl-5,6,7,8-tetrahydro-benzol [1,2,4]triazin-3-yl) [2,2]bipyridine, CyMe4-BTBP (Figure 1), has promising process potential, [11][12][13][14][15][16] as it has proven to be resistant towards acidic environments [17][18][19] and strong radiation from radioactive decomposition 13,20 Qualitative reasoning concerning the Lewis basicity of the extractant and the somewhat softer character of the actinoid(III) ions compared to the lanthanoid(III) ones has been used to explain the An(III)/Ln(III) separation capacity of N-PAH ligands. 32,33 An(III)/Ln(III) separation by CyMe4-BTBP has also been observed to vary with the solvent used.…”

Single Centrifugal Contactor Test of a Proposed Group Actinide Extraction Process for Partitioning and Transmutation Purposes

“…The two ligands (BTBP and TBP) were also found to not react and to extract independent of each other [15]. The actinides were separated from most of A c c e p t e d M a n u s c r i p t 4 the fission products (including the trivalent lanthanides) and corrosion/activation products with high separation factors after modifications of the extraction system using water-soluble complexing agents in the aqueous feed (bimet and mannitol) and in the subsequent scrub step (gluco lactone) [16][17][18]. An acid scrub step was found necessary as the GANEX solvent extracts large amounts of nitric acid [19], which compromises the actinide group stripping using glycolic acid.…”

Alkylation and pre-organisation of diglycolamide ligands on flexible platforms for nuclear waste treatment

“…However, CyMe4-BTBP in cyclohexanone formed Pd complexes that were soluble both in the organic and the aqueous phase, effectively reducing the selectivity of the extraction and causing loss of ligand; however higher HNO3 concentrations limited this effect. 248 The heptanol as opposed to nonanol and decanol (DAm ≈ 0.04). 249 In addition, longer chain alcohols also required longer time to reach equilibrium.…”