Journal article
Alteration of UO2+x under oxidizing conditions, Marshall Pass, Colorado, USA
Journal of Alloys and Compounds, Vol.444-445, pp.584-589
2007
Abstract
As a natural analogue of the processes and products of spent nuclear fuel (SNF) alteration, we have examined the sequence of phases that form during the alteration of natural UO2+x in a U-deposit at Marshall Pass, Colorado. We have determined the paragenesis of U(VI)-phases including the fate of trace elements: W, Mo, As, Sb, Cu, Ba, Ce, Y, Pb and Th. Enrichment of trace elements, especially W and Mo, in this system resulted in a unique alteration sequence: uraninite → amorphous U-oxyhydrate gel → schoepite(I)/vandendriesscheite/compreignacite → uranophane → schoepite(II)/"dehydrated" schoepite(I) → Ba-Mo-W-U phase/U-arsenates/U-Sb phase → "dehydrated schoepite" (II) → soddyite/swamboite. In this sequence, the Ba-Mo-W uranyl phase and U-Sb phase are newly characterized phases. These results suggest that the UO2+x alteration, involving higher concentrations of certain radionuclides and metallic compounds, may lead to a different paragenesis of U(VI)-phases, as compared with the expected alteration sequence of UO2 interacting with a typical groundwaters. This was also noted in a previous study of the alteration of Pb-rich uraninite [R.J. Finch, R.C. Ewing, J. Nucl. Mater. 190 (1992) 133-156]. Some trace elements, such as CaO 2.08 wt.%, PbO 1.69 wt.%, WO3 1.39 wt.%, As2O3 0.50 wt.% and MoO3 0.41 wt.%, can locally concentrate, but still form uranyl phases. As a consequence, the mobility of U and radionuclides is governed by the stability of these metal-uranyl phases, such as Pb-oxide hydrates, Ba-uranyl molybdates/ tungstates and U-antimonate.
Details
- Title
- Alteration of UO2+x under oxidizing conditions, Marshall Pass, Colorado, USA
- Authors/Creators
- A.P. Deditius (Author/Creator) - University of MichiganS. Utsunomiya (Author/Creator) - University of MichiganR.C. Ewing (Author/Creator) - University of Michigan
- Publication Details
- Journal of Alloys and Compounds, Vol.444-445, pp.584-589
- Publisher
- Elsevier B.V.
- Identifiers
- 991005542179807891
- Copyright
- © 2007 Elsevier B.V.
- Murdoch Affiliation
- Murdoch University
- Language
- English
- Resource Type
- Journal article
UN Sustainable Development Goals (SDGs)
This output has contributed to the advancement of the following goals:
Source: InCites
Metrics
38 Record Views
InCites Highlights
These are selected metrics from InCites Benchmarking & Analytics tool, related to this output
- Citation topics
- 8 Earth Sciences
- 8.242 Nuclear Geology
- 8.242.1362 Uranium Chemistry
- Web Of Science research areas
- Chemistry, Physical
- Materials Science, Multidisciplinary
- Metallurgy & Metallurgical Engineering
- ESI research areas
- Materials Science