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Technetium management in liquid-liquid distribution systems for uranium extraction by DEHiBA

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Published/Copyright: December 17, 2025
Radiochimica Acta
From the journal Radiochimica Acta Volume 114 Issue 3

Abstract

Technetium-99 is one of the most problematic byproducts of nuclear fission due to its high environmental mobility and unpredictable solution chemistry which complicate the isolation and storage options. Efficient management of technetium is difficult in flowsheets designed to recover uranium from used nuclear fuel effluents due to pertechnetate anion’s tendency to follow the uranyl cation. The accessible standard electrode potentials of technetium have offered a gateway to its efficient routing away from uranium based on the manipulation of Tc redox speciation. The intra-molecular oxoanion recognition has been a much less explored strategy, where the main obstacle resides with binding specificity for pertechnetate in mixtures containing great excess of nitrate. This work explores molecular constructs based on the guanidinium moiety, seeking affinity for a pertechnetate anion as expressed in the observable influence on the liquid-liquid partitioning of Tc-99. The unsubstituted guanidinium cations showed evidence of pertechnetate recognition, yielding a modest impact on Tc distribution in mixtures containing a thousand-fold excess of nitrate anion. Guanidiniums containing an amino substituent are oxidized via a Tc-catalyzed redox mechanism which reduces technetium to its tetravalent state. This transformation affords TcO2+ species, which are excluded from the DEHiBA uranyl solvate in the organic phase. As a result, over 90 % of Tc-99 can be efficiently scrubbed when equilibrated with moderately acidic mixtures of diaminoguanidine.

Keywords: technetium; uranium; pertechnetate; solvent extraction; diaminoguanidine
Corresponding author: Peter R. Zalupski, Radiochemical Separations and Radiation Science Department, Idaho National Laboratory, 2525 N. Fremont Ave, Idaho Falls, Idaho, USA, E-mail:

Funding source: U.S. Department of Energy, Office of Nuclear Energy

  1. Research ethics: Not applicable.

  2. Informed consent: Not applicable.

  3. Author contributions: All authors have accepted responsibility for the entire content of this manuscript and approved its submission.

  4. Use of Large Language Models, AI and Machine Learning Tools: None declared.

  5. Conflict of interest: The authors state no conflict of interest.

  6. Research funding: The experimental work conducted by CDP, TSG and PRZ at the Idaho National Laboratory was supported by the Nuclear Technology Research and Development Program, Office of Nuclear Energy, DOE Idaho Operations Office, under contract DE-AC07-05ID14517. The synthetic work by JM and SJ-P was supported by the Nuclear Technology Research and Development Program, Office of Nuclear Energy, U.S. Department of Energy, under contract DE-AC05-00OR22725.

  7. Data availability: Not applicable.

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Received: 2025-09-30
Accepted: 2025-12-02
Published Online: 2025-12-17
Published in Print: 2026-03-26

© 2025 Walter de Gruyter GmbH, Berlin/Boston

Articles in the same Issue

  1. Frontmatter
  2. Efficient removal of U(VI) by self-assembly organic-embedded mesoporous silica spheres
  3. Efficient adsorption of uranium and rhenium using magnetic bentonite: mechanisms and thermodynamics
  4. Electroextraction of fission element thulium from copper electrode in LiCl–KCl molten salt electrorefining process and its kinetic analysis
  5. Technetium management in liquid-liquid distribution systems for uranium extraction by DEHiBA
  6. A new type of 103Pd/103mRh generator
  7. Study of dissolved radon and optimization of 211Rn/211At generator
  8. Improving the sensitivity of atmospheric carbon-14 measurement by liquid scintillation counting through method optimization
  9. Natural radioactivity and radiological risk in spices from southeastern Turkey: a pre-earthquake baseline study
https://doi.org/10.1515/ract-2025-0094
Keywords for this article
technetium; uranium; pertechnetate; solvent extraction; diaminoguanidine

Articles in the same Issue

  1. Frontmatter
  2. Efficient removal of U(VI) by self-assembly organic-embedded mesoporous silica spheres
  3. Efficient adsorption of uranium and rhenium using magnetic bentonite: mechanisms and thermodynamics
  4. Electroextraction of fission element thulium from copper electrode in LiCl–KCl molten salt electrorefining process and its kinetic analysis
  5. Technetium management in liquid-liquid distribution systems for uranium extraction by DEHiBA
  6. A new type of 103Pd/103mRh generator
  7. Study of dissolved radon and optimization of 211Rn/211At generator
  8. Improving the sensitivity of atmospheric carbon-14 measurement by liquid scintillation counting through method optimization
  9. Natural radioactivity and radiological risk in spices from southeastern Turkey: a pre-earthquake baseline study
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