Abstract
How do you characterise the contents of a sealed nuclear waste package
without breaking it open? This question is important when the contained
corrosion products are potentially reactive with air and radioactive.
Synchrotron X-rays have been used to perform micro-scale in-situ
observation and characterisation of uranium encapsulated in grout; a
simulation for a typical intermediate level waste storage packet. X-ray
tomography and X-ray powder diffraction generated both qualitative and
quantitative data from a grout-encapsulated uranium sample before, and
after, deliberately constrained H2 corrosion. Tomographic
reconstructions provided a means of assessing the extent, rates and
character of the corrosion reactions by comparing the relative densities
between the materials and the volume of reaction products. The
oxidation of uranium in grout was found to follow the anoxic U + H2O
oxidation regime, and the pore network within the grout was observed to
influence the growth of uranium hydride sites across the metal surface.
Powder diffraction analysis identified the corrosion products as UO2 and UH3,
and permitted measurement of corrosion-induced strain. Together, X-ray
tomography and diffraction provide means of accurately determining the
types and extent of uranium corrosion occurring, thereby offering a
future tool for isolating and studying the reactions occurring in real
full-scale waste package systems.
Original language | English |
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Pages (from-to) | 221-227 |
Number of pages | 7 |
Journal | Journal of Hazardous Materials |
Volume | 285 |
Issue number | 0 |
Early online date | 6 Dec 2014 |
DOIs | |
Publication status | Published - 21 Mar 2015 |
Keywords
- Uranium
- Grout
- Synchrotron X-ray tomography
- X-ray powder diffraction
- Uranium hydride
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Profiles
-
Professor Thomas Bligh Scott
- Interface Analysis Centre - Professor in Materials
- Cabot Institute for the Environment
- The Bristol Centre for Nanoscience and Quantum Information
Person: Academic , Member