Rights statement: This is the author’s version of a work that was accepted for publication in Journal of Nuclear Materials. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Journal of Nuclear Materials, 464, 2016 DOI: 10.1016/j.jnucmat.2015.04.007
Accepted author manuscript, 1.03 MB, PDF document
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Final published version
Research output: Contribution to Journal/Magazine › Journal article › peer-review
| <mark>Journal publication date</mark> | 09/2015 |
|---|---|
| <mark>Journal</mark> | Journal of Nuclear Materials |
| Volume | 464 |
| Number of pages | 11 |
| Pages (from-to) | 86-96 |
| Publication Status | Published |
| Early online date | 15/04/15 |
| <mark>Original language</mark> | English |
For the first time the effect of hydrogen peroxide on the dissolution of electrodeposited uranium oxide films on 316L stainless steel planchets (acting as simulant uranium-contaminated metal surfaces) has been studied. Analysis of the H2O2-mediated film dissolution processes via open circuit potentiometry, alpha counting and SEM/EDX imaging has shown that in near-neutral solutions of pH 6.1 and at [H2O2] 0.1 mol dm(-3) the uranium oxide film, again in analogy to common corrosion processes, behaves as if in a transpassive state and begins to dissolve.
This transition from passive to transpassive behaviour in the effect of peroxide concentration on UO2 films has not hitherto been observed or explored, either in terms of corrosion processes or otherwise. Through consideration of thermodynamic solubility product and complex formation constant data, we attribute the transition to the formation of soluble uranyl-peroxide complexes under mildly alkaline, high [H2O2] conditions - a conclusion that has implications for the design of both acid minimal, metal ion oxidant-free decontamination strategies with low secondary waste arisings, and single step processes for spent nuclear fuel dissolution such as the Carbonate-based Oxidative Leaching (COL) process. (C) 2015 Elsevier B.V. All rights reserved.