Improving Americium/Curium Separation Factors in the AmSel Process through Symmetry Lowering of the Diglycolamide Extractant.

Partitioning and transmutation are important strategies for closing the nuclear fuel cycle. The diglycolamide extractant TODGA has played a major role in the development of solvent extraction processes for nuclear fuel reprocessing due to its good extraction performance, its hydrolytic and radiolytic stability, and its compliance with the CHON principle. However, due to drawbacks such as the tendency to form a third phase during extraction if no phase modifiers are used, continued research on diglycolamide-type extractants has led to the development of diglycolamides with decreased symmetry.

Separation of americium from highly active raffinates by an innovative variant of the AmSel process based on the ionic liquid Aliquat-336 nitrate.

A new variant of the AmSel (Americium Selective Separation) system for the separation of Am(iii) from a PUREX raffinate was tested in which the aliphatic diluent was replaced by the ionic liquid Aliquat-336 nitrate. For this ionic liquid variant, the kinetics, and the influence of both the HNO concentration and the ligand concentration on the stripping were evaluated. In addition, both the original AmSel system, and the ionic liquid variant were demonstrated on a simulated highly active raffinate.

Selective extraction of trivalent actinides using CyMeBTPhen in the ionic liquid Aliquat-336 nitrate.

The extraction of Am(iii), Cm(iii) and Eu(iii) by 2,9-bis(5,5,8,8-tetramethyl-5,6,7,8-tetrahydro-1,2,4-benzotriazin-3-yl)-1,10-phenanthroline (CyMeBTPhen) from nitric acid solution was studied using the ionic liquid Aliquat-336 nitrate ([A336][NO]) as diluent. Results show a high selectivity of the solvent for Am(iii) and Cm(iii) over Eu(iii), but rather slow extraction kinetics. The kinetics of CyMeBTPhen were largely improved by the addition of 0.

Stability of europium(ii) in aqueous nitrate solutions.

In the lanthanide series, Eu3+ is most easily reduced to its divalent state. Reduction of Eu3+ has been studied extensively in aqueous media that are insensitive to reducing conditions. Recently, it has been reported that reduction of Eu3+ is also feasible in aqueous nitrate solutions and that Eu2+ remained sufficiently stable in these media to conduct separation experiments.

Thorium-229 quantified in historical Thorium-228 capsules.

Thorium-229 is a valuable, but scarce, radionuclide for nuclear clock applications or targeted alpha therapy. While it is mostly produced by the decay of U, Th can also be produced by neutron irradiation of Ra. At SCK•CEN, capsules containing mainly Th (by-product of Ra irradiation) were characterized to quantify the present amounts of Th, Th, Ac, Ra with high resolution gamma spectroscopy, after a decay period of 40 years in which Th has decayed.