Cargando…
Oxidation of Micro- and Nanograined UO(2) Pellets by In Situ Synchrotron X-ray Diffraction
[Image: see text] When in contact with oxidizing media, UO(2) pellets used as nuclear fuel may transform into U(4)O(9), U(3)O(7), and U(3)O(8). The latter starts forming by stress-induced phase transformation only upon cracking of the pristine U(3)O(7) and is associated with a 36% volumetric expansi...
Autores principales: | , , , , , , |
---|---|
Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
American Chemical Society
2022
|
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9052414/ https://www.ncbi.nlm.nih.gov/pubmed/35044161 http://dx.doi.org/10.1021/acs.inorgchem.1c02652 |
_version_ | 1784696778008821760 |
---|---|
author | De Bona, Emanuele Popa, Karin Walter, Olaf Cologna, Marco Hennig, Christoph Scheinost, Andreas C. Prieur, Damien |
author_facet | De Bona, Emanuele Popa, Karin Walter, Olaf Cologna, Marco Hennig, Christoph Scheinost, Andreas C. Prieur, Damien |
author_sort | De Bona, Emanuele |
collection | PubMed |
description | [Image: see text] When in contact with oxidizing media, UO(2) pellets used as nuclear fuel may transform into U(4)O(9), U(3)O(7), and U(3)O(8). The latter starts forming by stress-induced phase transformation only upon cracking of the pristine U(3)O(7) and is associated with a 36% volumetric expansion with respect to the initial UO(2). This may pose a safety issue for spent nuclear fuel (SNF) management as it could imply a confinement failure and hence dispersion of radionuclides within the environment. In this work, UO(2) with different grain sizes (representative of the grain size in different radial positions in the SNF) was oxidized in air at 300 °C, and the oxidation mechanisms were investigated using in situ synchrotron X-ray diffraction. The formation of U(3)O(8) was detected only in UO(2) pellets with larger grains (3.08 ± 0.06 μm and 478 ± 17 nm), while U(3)O(8) did not develop in sintered UO(2) with a grain size of 163 ± 9 nm. This result shows that, in dense materials, a sufficiently fine microstructure inhibits both the cracking of U(3)O(7) and the subsequent formation of U(3)O(8). Hence, the nanostructure prevents the material from undergoing significant volumetric expansion. Considering that the peripheral region of SNF is constituted by the high burnup structure, characterized by 100–300 nm-sized grains and micrometric porosity, these findings are relevant for a better understanding of the spent nuclear fuel behavior and hence for the safety of the nuclear waste storage. |
format | Online Article Text |
id | pubmed-9052414 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2022 |
publisher | American Chemical Society |
record_format | MEDLINE/PubMed |
spelling | pubmed-90524142022-04-29 Oxidation of Micro- and Nanograined UO(2) Pellets by In Situ Synchrotron X-ray Diffraction De Bona, Emanuele Popa, Karin Walter, Olaf Cologna, Marco Hennig, Christoph Scheinost, Andreas C. Prieur, Damien Inorg Chem [Image: see text] When in contact with oxidizing media, UO(2) pellets used as nuclear fuel may transform into U(4)O(9), U(3)O(7), and U(3)O(8). The latter starts forming by stress-induced phase transformation only upon cracking of the pristine U(3)O(7) and is associated with a 36% volumetric expansion with respect to the initial UO(2). This may pose a safety issue for spent nuclear fuel (SNF) management as it could imply a confinement failure and hence dispersion of radionuclides within the environment. In this work, UO(2) with different grain sizes (representative of the grain size in different radial positions in the SNF) was oxidized in air at 300 °C, and the oxidation mechanisms were investigated using in situ synchrotron X-ray diffraction. The formation of U(3)O(8) was detected only in UO(2) pellets with larger grains (3.08 ± 0.06 μm and 478 ± 17 nm), while U(3)O(8) did not develop in sintered UO(2) with a grain size of 163 ± 9 nm. This result shows that, in dense materials, a sufficiently fine microstructure inhibits both the cracking of U(3)O(7) and the subsequent formation of U(3)O(8). Hence, the nanostructure prevents the material from undergoing significant volumetric expansion. Considering that the peripheral region of SNF is constituted by the high burnup structure, characterized by 100–300 nm-sized grains and micrometric porosity, these findings are relevant for a better understanding of the spent nuclear fuel behavior and hence for the safety of the nuclear waste storage. American Chemical Society 2022-01-19 2022-01-31 /pmc/articles/PMC9052414/ /pubmed/35044161 http://dx.doi.org/10.1021/acs.inorgchem.1c02652 Text en © 2022 The Authors. Published by American Chemical Society https://creativecommons.org/licenses/by/4.0/Permits the broadest form of re-use including for commercial purposes, provided that author attribution and integrity are maintained (https://creativecommons.org/licenses/by/4.0/). |
spellingShingle | De Bona, Emanuele Popa, Karin Walter, Olaf Cologna, Marco Hennig, Christoph Scheinost, Andreas C. Prieur, Damien Oxidation of Micro- and Nanograined UO(2) Pellets by In Situ Synchrotron X-ray Diffraction |
title | Oxidation of Micro- and Nanograined UO(2) Pellets by In Situ Synchrotron X-ray Diffraction |
title_full | Oxidation of Micro- and Nanograined UO(2) Pellets by In Situ Synchrotron X-ray Diffraction |
title_fullStr | Oxidation of Micro- and Nanograined UO(2) Pellets by In Situ Synchrotron X-ray Diffraction |
title_full_unstemmed | Oxidation of Micro- and Nanograined UO(2) Pellets by In Situ Synchrotron X-ray Diffraction |
title_short | Oxidation of Micro- and Nanograined UO(2) Pellets by In Situ Synchrotron X-ray Diffraction |
title_sort | oxidation of micro- and nanograined uo(2) pellets by in situ synchrotron x-ray diffraction |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9052414/ https://www.ncbi.nlm.nih.gov/pubmed/35044161 http://dx.doi.org/10.1021/acs.inorgchem.1c02652 |
work_keys_str_mv | AT debonaemanuele oxidationofmicroandnanograineduo2pelletsbyinsitusynchrotronxraydiffraction AT popakarin oxidationofmicroandnanograineduo2pelletsbyinsitusynchrotronxraydiffraction AT walterolaf oxidationofmicroandnanograineduo2pelletsbyinsitusynchrotronxraydiffraction AT colognamarco oxidationofmicroandnanograineduo2pelletsbyinsitusynchrotronxraydiffraction AT hennigchristoph oxidationofmicroandnanograineduo2pelletsbyinsitusynchrotronxraydiffraction AT scheinostandreasc oxidationofmicroandnanograineduo2pelletsbyinsitusynchrotronxraydiffraction AT prieurdamien oxidationofmicroandnanograineduo2pelletsbyinsitusynchrotronxraydiffraction |