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

Journal Article · · Journal of Radioanalytical and Nuclear Chemistry
 [1];  [2];  [3]
  1. Idaho National Lab. (INL), Idaho Falls, ID (United States)
  2. Oregon State Univ., Corvallis, OR (United States); Academy of Sciences of the Czech Republic (ASCR), Prague (Czech Republic)
  3. Oregon State Univ., Corvallis, OR (United States)

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.

Research Organization:
Idaho National Laboratory, Idaho Falls, ID (United States)
Sponsoring Organization:
USDOE; USDOE Office of Nuclear Energy (NE)
Grant/Contract Number:
AC07-05ID14517
OSTI ID:
1358433
Alternate ID(s):
OSTI ID: 22500143
Report Number(s):
INL/JOU--15-36192; PII: 4530
Journal Information:
Journal of Radioanalytical and Nuclear Chemistry, Journal Name: Journal of Radioanalytical and Nuclear Chemistry Journal Issue: 3 Vol. 308; ISSN 0236-5731
Publisher:
SpringerCopyright Statement
Country of Publication:
United States
Language:
English

References (12)

The role of oxidizing radicals in neptunium speciation in γ-irradiated nitric acid journal July 2012
Radiolytic yields G(HNO2) and G(H2O2) in the aqueous nitric acid system journal January 1973
Neptunium (V) Oxidation by Nitrous Acid in Nitric Acid journal January 2012
Bicyclic and Acyclic Diamides:  Comparison of Their Aqueous Phase Binding Constants with Nd(III), Am(III), Pu(IV), Np(V), Pu(VI), and U(VI) journal December 2004
Tributylphosphate Extraction Behavior of Bismuthate-Oxidized Americium journal August 2008
Kinetics of HNO 2 Catalyzed Oxidation of Neptunium(V) by Aqueous Solutions of Nitric Acid 1 journal May 1959
Effect of Gamma Irradiation on the Oxidation State of Neptunium in Nitric Acid in the Presence of Selected Scavengers journal July 2010
Neptunium Extraction and Stability in the GANEX Solvent: 0.2 M TODGA/0.5 M DMDOHEMA/Kerosene journal October 2012
Progress towards the Full Recovery of Neptunium in an Advanced PUREX Process journal July 2013
Equilibrium of Nitrous Acid-Catalyzed Oxidation of Neptunium in Nitric Acid-TBP Extraction System journal January 1995
Kinetics of Nitrous Acid-Catalyzed Oxidation of Neptunium in Nitric Acid-TBP Extraction System journal February 1995
The redox chemistry of neptunium in γ -irradiated aqueous nitric acid journal April 2013

Cited By (1)

Exploring crown-ether functionalization on the stabilization of hexavalent neptunium journal January 2019

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