Technetium chemistry in a novel group actinide extraction process
Journal article, 2013

A newly developed method for advanced reprocessing of used nuclear fuel is the Group ActiNide EXtraction (GANEX) process. It is a liquid-liquid extraction process that aims at extracting all the actinides as a group from dissolved used nuclear fuel. This extraction can either be performed after a removal of the bulk uranium or directly on the dissolution liquor. At Chalmers University of Technology in Sweden a solvent that utilizes tributyl-phosphate (TBP) and a molecule from the bis-triazine bipyridine (BTBP) class of ligands dissolved in cyclohexanone has been developed for the use in a GANEX process. Previously the system has not been tested with the presence of technetium that is one of the major fission products. Technetium is often considered a problem within reprocessing since it has a chemical behaviour that differs from most other elements in the spent fuel. Therefore, a special emphasis was put on the investigation of technetium in the selected GANEX system. It was shown that technetium is readily extracted by the GANEX solvent and that cyclohexanone is the main extractant when no other metals were present in the system. It was also found that the presence of uranium decreased the overall technetium extraction despite a slight co-extraction with TBP, while irradiation of the GANEX solvent to large doses ([>1 MGy) increased its technetium extraction capability. It was also discovered that an increased nitrate concentration in the aqueous phase and an addition of other fission products both inhibited the technetium extraction even though fission product loading most likely changed the extraction mechanism to co-extraction by BTBP.

Cyclohexanone

GANEX

BTBP

Technetium

Author

Emma Aneheim

Chalmers, Chemical and Biological Engineering, Nuclear Chemistry

Christian Ekberg

Chalmers, Chemical and Biological Engineering, Nuclear Chemistry

A. Littley

Chalmers, Chemical and Biological Engineering, Nuclear Chemistry

Elin Löfström Engdahl

Chalmers, Chemical and Biological Engineering, Nuclear Chemistry

Gunnar Skarnemark

Chalmers, Chemical and Biological Engineering, Nuclear Chemistry

Journal of Radioanalytical and Nuclear Chemistry

0236-5731 (ISSN) 1588-2780 (eISSN)

Vol. 296 2 743-748

Subject Categories

Inorganic Chemistry

DOI

10.1007/s10967-012-1928-2

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5/24/2024