1
|
Massonnet M, Claparede L, Martinez J, Martin PM, Hunault MOJY, Prieur D, Mesbah A, Dacheux N, Clavier N. Influence of Sintering Conditions on the Structure and Redox Speciation of Homogeneous (U,Ce)O 2+δ Ceramics: A Synchrotron Study. Inorg Chem 2023; 62:7173-7185. [PMID: 37133506 DOI: 10.1021/acs.inorgchem.2c03945] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Although uranium-cerium dioxides are frequently used as a surrogate material for (U,Pu)O2-δ nuclear fuels, there is currently no reliable data regarding the oxygen stoichiometry and redox speciation of the cations in such samples. In order to fill this gap, this manuscript details a synchrotron study of highly homogeneous (U,Ce)O2±δ sintered samples prepared by a wet-chemistry route. HERFD-XANES spectroscopy led to determining accurately the O/M ratios (with M = U + Ce). Under a reducing atmosphere (pO2 ≈ 6 × 10-29 atm at 650 °C), the oxides were found to be close to O/M = 2.00, while the O/M ratio varied with the sintering conditions under argon (pO2 ≈ 3 × 10-6 atm at 650 °C). They globally appeared to be hyperstoichiometric (i.e., O/M > 2.00) with the departure from the dioxide stoichiometry decreasing with both the cerium content in the sample and the sintering temperature. Nevertheless, such a deviation from the ideal O/M = 2.00 ratio was found to generate only moderate structural disorder from EXAFS data at the U-L3 edge as all the samples retained the fluorite-type structure of the UO2 and CeO2 parent compounds. The determination of accurate lattice parameters owing to S-PXRD measurements led to complementing the data reported in the literature by various authors. These data were consistent with an empirical relation linking the unit cell parameter, the chemical composition, and the O/M stoichiometry, showing that the latter can be evaluated simply within a ± 0.02 uncertainty.
Collapse
Affiliation(s)
- Malvina Massonnet
- ICSM, Univ Montpellier, CEA, CNRS, ENSCM, Bagnols/Cèze 30207, France
| | - Laurent Claparede
- ICSM, Univ Montpellier, CEA, CNRS, ENSCM, Bagnols/Cèze 30207, France
| | - Julien Martinez
- CEA, DES, ISEC, DMRC, Univ Montpellier, Marcoule, Bagnols-sur-Ceze 30207, France
| | - Philippe M Martin
- CEA, DES, ISEC, DMRC, Univ Montpellier, Marcoule, Bagnols-sur-Ceze 30207, France
| | | | - Damien Prieur
- Institute of Resource Ecology, Helmholtz Zentrum Dresden-Rossendorf (HZDR), 01314 Dresden, Germany
- The Rossendorf Beamline at ESRF - The European Synchrotron, 38043 Grenoble Cedex 9, France
| | - Adel Mesbah
- ICSM, Univ Montpellier, CEA, CNRS, ENSCM, Bagnols/Cèze 30207, France
- CNRS, IRCELYON, Univ Lyon, Université Claude Bernard Lyon 1, 69626 Villeurbanne, France
| | - Nicolas Dacheux
- ICSM, Univ Montpellier, CEA, CNRS, ENSCM, Bagnols/Cèze 30207, France
| | - Nicolas Clavier
- ICSM, Univ Montpellier, CEA, CNRS, ENSCM, Bagnols/Cèze 30207, France
| |
Collapse
|
2
|
Effect of the thorium oxide content on the leaching of a mixed thorium-uranium oxide fuel. J Radioanal Nucl Chem 2022. [DOI: 10.1007/s10967-022-08347-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
AbstractLeaching of uranium from uranium oxide fuel in contact with water can be a radiation hazard problem in the case of fuel cladding failure, either during nuclear reactor operation or in an interim storage, as well as in a final repository. One way to mitigate this is to reduce the solubility of the fuel matrix by the mixing uranium oxide with a compound which is less soluble but otherwise of similar properties. In this paper, the effect of thorium oxide content on the leaching of the uranium oxide matrix is investigated. The method was to study the leaching of the uranium oxide fuel matrix as a function of a varying content of thorium oxide, using materials manufactured by powder co-milling. It was found that the substitution of more than 25% UO2 with ThO2 reduces the matrix leaching by more than one order of magnitude in most of the different leaching solutions investigated. The substitution of 7% UO2 with ThO2 results in a reduction of matrix leaching by 10–90%, depending on the concentration of borate and dissolved oxygen in the leaching solution.
Collapse
|
3
|
Zhang R, Hou W, Wang H, Hu E, Lei Z, Hu F, Zhou W, Wang Q. Oxidative leaching of sandstone uranium ore assisted by ozone micro-nano bubbles. J Radioanal Nucl Chem 2022. [DOI: 10.1007/s10967-022-08241-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
4
|
Grambow B, Nitta A, Shibata A, Koma Y, Utsunomiya S, Takami R, Fueda K, Ohnuki T, Jegou C, Laffolley H, Journeau C. Ten years after the NPP accident at Fukushima : review on fuel debris behavior in contact with water. J NUCL SCI TECHNOL 2021. [DOI: 10.1080/00223131.2021.1966347] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Bernd Grambow
- SUBATECH (IMT Atlantique, CNRS-IN2P3, University De Nantes), Nantes, France
- Advanced Science Research Center, Japan Atomic Energy Agency, Ibaraki, Japan
| | - Ayako Nitta
- Collaborative Laboratories for Advanced Decommissioning Science, Japan Atomic Energy Agency(JAEA), Ibaraki, Japan
| | - Atsuhiro Shibata
- Collaborative Laboratories for Advanced Decommissioning Science, Japan Atomic Energy Agency(JAEA), Ibaraki, Japan
| | - Yoshikazu Koma
- Nuclear Fuel Cycle Engineering Laboratories, Japan Atomic Energy Agency, Ibaraki, Japan
| | | | - Ryu Takami
- Department of Chemistry, Kyushu University, Fukuoka, Japan
| | - Kazuki Fueda
- Department of Chemistry, Kyushu University, Fukuoka, Japan
| | - Toshihiko Ohnuki
- NPO Environmental Sustainable Research Laboratory, Tokyo Institute of Technology, Meguro-ku, Japan
| | - Christophe Jegou
- CEA, DES, ISEC, DE2D, University of Montpellier, Marcoule, France
| | - Hugo Laffolley
- SUBATECH (IMT Atlantique, CNRS-IN2P3, University De Nantes), Nantes, France
- CEA, DES, IRESNE, DTN, Severe Accident Experimental Laboratory, Saint-Paul-Lez-Durance, France
| | - Christophe Journeau
- CEA, DES, IRESNE, DTN, Severe Accident Experimental Laboratory, Saint-Paul-Lez-Durance, France
| |
Collapse
|
5
|
Desigan N, Bhatt N, Shetty MA, Sreekumar GKP, Pandey NK, Kamachi Mudali U, Natarajan R, Joshi JB. Dissolution of nuclear materials in aqueous acid solutions. REV CHEM ENG 2019. [DOI: 10.1515/revce-2017-0063] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
The quantitative understanding of the dissolution of nuclear fuel materials is essential for the process design and development of an industrial-scale nuclear fuel reprocessing plant. The main objective of this review article is to analyze the published data related to the dissolution of important nuclear materials, namely, urania, plutonia, thoria, and their oxides in the existing literature. The published results on rate-controlling step and reaction mechanism of dissolution processes are reconciled and reviewed in this work. Clear suggestions are made for future research work for the identification of rate-controlling step. Suggestions are also provided to overcome the shortfalls in the published data for the identification of intrinsic kinetics and mass-transfer rates.
Collapse
|
6
|
Marc P, Magnaldo A, Vaudano A, Delahaye T, Schaer É. Dissolution of uranium dioxide in nitric acid media: what do we know? EPJ NUCLEAR SCIENCES & TECHNOLOGIES 2017. [DOI: 10.1051/epjn/2017005] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
7
|
Simonnet M, Barré N, Drot R, Naour CL, Sladkov V, Delpech S. Multiparametric study of thorium oxide dissolution in aqueous media. RADIOCHIM ACTA 2016. [DOI: 10.1515/ract-2016-2607] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
Thorium oxide is poorly soluble: unlike uranium oxide, concentrated nitric acid medium is not sufficient to get quantitative dissolution. Addition of small amounts of fluoride is required to achieve thorium oxide total dissolution. The effect of several parameters on thorium oxide dissolution in order to optimize the dissolution conditions is reported in this paper. Thus the influence of solid characteristics, dissolution method, temperature and composition of dissolution medium on ThO2 dissolution rate has been studied. No complexing agents tested other than fluoride allows total dissolution. Beyond a given HF concentration a decrease of the dissolution rate is observed due to the formation of a precipitate at the solid/solution interface. It was demonstrated by XPS measurements that this precipitate is constituted of thorium fluoride (ThF4) formed during the ThO2 dissolution. The low concentration of HF required to achieve a total dissolution and the activation energy value measured tends to show a catalytic effect of HF on the dissolution process.
Collapse
Affiliation(s)
- Marie Simonnet
- Institut de Physique Nucléaire, CNRS-IN2P3, Univ. Paris-Sud, Université Paris-Saclay, 91406 Orsay Cedex, France
| | - Nicole Barré
- Institut de Physique Nucléaire, CNRS-IN2P3, Univ. Paris-Sud, Université Paris-Saclay, 91406 Orsay Cedex, France
| | - Romuald Drot
- Institut de Physique Nucléaire, CNRS-IN2P3, Univ. Paris-Sud, Université Paris-Saclay, 91406 Orsay Cedex, France
| | - Claire Le Naour
- Institut de Physique Nucléaire, CNRS-IN2P3, Univ. Paris-Sud, Université Paris-Saclay, 91406 Orsay Cedex, France
| | - Vladimir Sladkov
- Institut de Physique Nucléaire, CNRS-IN2P3, Univ. Paris-Sud, Université Paris-Saclay, 91406 Orsay Cedex, France
| | - Sylvie Delpech
- Institut de Physique Nucléaire, CNRS-IN2P3, Univ. Paris-Sud, Université Paris-Saclay, 91406 Orsay Cedex, France
| |
Collapse
|