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The development of liquid-liquid separation processes for the effective removal of minor actinide Am(III) from used nuclear fuel (UNF) using ligand-based strategies continues to be an area of significant research focus. The current investigation demonstrates the efficacy of a nitrogen-based bis-triazinyl pyridine (BTP) derivative to selectively extract Am(III) from nitric acid solutions containing light lanthanides. The performance of 3,3ʹ-dimethoxy-phenyl-bis-1,2,4-triazinyl-2,6-pyridine (MOB-BTP) was compared to that of a camphor-substituted BTP (CA-BTP). The results of this investigation demonstrate the novel 3,3ʹ-methoxy-BTP extractant dissolved in a polar diluent was a more efficient extractant for Am(III) at a lower concentration than CA-BTP under comparable conditions. [ABSTRACT FROM AUTHOR]

The separation of americium(III) from europium(III) was achieved utilizing a bis-2,6-(5,6,7,8-tetrahydro-5,9,9-trimethyl-5,8-methano-1,2,4-benzotriazin-3-yl) pyridine (CA-BTP) chromatographic resin. The extraction chromatographic materials were prepared using various concentrations of CA-BTP. This new, hydrolytically stable extractant was impregnated on an inert polymeric support at 40% loading. The uptake of Am(III) and Eu(III) by this material from 0.1 to 4.0 M aqueous HNO solutions was measured. The resulting dry weight distribution ratios, D , indicated a strong preference for Am(III) with little affinity for Eu(III). These results are similar to recently reported solvent extraction studies indicating a maximum uptake of Am(III) in the 0.5-1.0 M HNO range. The resin preparation, performance, and characterization of the Am/Eu separation are reported herein. [ABSTRACT FROM AUTHOR]

Among the different components present in spent nuclear fuel, long-lived trivalent actinides are particularly difficult to separate from the shorter-lived lanthanide fission products due to their similar chemical properties. Selective extraction of americium from acidic solution (up to 2M HNO3) containing tenth molar quantities of lanthanides has been achieved using neutral pyridine-based ligands dissolved in polar diluents. Nitrogen-based Bis Triazinyl Pyridine (BTP) ligands are desirable for both their excellent An/Ln selectivity and incinerability. Results pertaining to ligand solubility, kinetics, hydrolytic stability, and extraction performance in various nitric acid environments are presented. [ABSTRACT FROM AUTHOR]