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The redox chemistry of neptunium in γ-irradiated aqueous nitric acid in the presence of an organic phase

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Abstract

The radiolytic changes in oxidation state for solutions of initially Np(V) and/or Np(VI) were investigated by gamma-irradiation in conjunction with UV/Vis spectroscopy of the aqueous phase. Samples were irradiated in varying concentrations of nitric acid, and with or without the presence of 30 % TBP in dodecane. At short irradiation times Np(V) was oxidized to Np(VI), even in the presence of the organic phase. Upon the radiolytic production of sufficient amounts of nitrous acid, reduction of Np(VI) to Np(V) occurred in both phases. This was accompanied by stripping of the previously extracted Np(VI). Nitric acid concentrations of 6 M mitigated this reduction.

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Acknowledgments

This work was supported by the Idaho National Laboratory LDRD program, under DOE Idaho Operations Office contract DE-AC07-99ID13727. During 2012–2015, M. Precek was supported with post-doc funding by the European Social Fund and the state budget of the Czech Republic (Project No. CZ.1.07/2.3.00/30.0057).

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Author notes

  1. Martin Precek

    Present address: Institute of Physics, Academy of the Sciences of the Czech Republic, Prague, Czech republic

Authors and Affiliations

  1. Aqueous Separations and Radiochemistry Department, Idaho National Laboratory, Idaho Falls, ID, USA

    Bruce J. Mincher

  2. Department of Chemistry, Oregon State University, Corvallis, OR, USA

    Martin Precek & Alena Paulenova

Authors
  1. Bruce J. Mincher
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  2. Martin Precek
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  3. Alena Paulenova
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Correspondence to Bruce J. Mincher.

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Mincher, B.J., Precek, M. & Paulenova, A. The redox chemistry of neptunium in γ-irradiated aqueous nitric acid in the presence of an organic phase. J Radioanal Nucl Chem 308, 1005–1009 (2016). https://doi.org/10.1007/s10967-015-4530-6

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  • DOI: https://doi.org/10.1007/s10967-015-4530-6

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