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Diagenetic formation of uranium-silica polymers in lake sediments over 3,300 years. Proc Natl Acad Sci U S A 2021; 118:2021844118. [PMID: 33479173 DOI: 10.1073/pnas.2021844118] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The long-term fate of uranium-contaminated sediments, especially downstream former mining areas, is a widespread environmental challenge. Essential for their management is the proper understanding of uranium (U) immobilization mechanisms in reducing environments. In particular, the long-term behavior of noncrystalline U(IV) species and their possible evolution to more stable phases in subsurface conditions is poorly documented, which limits our ability to predict U long-term geochemical reactivity. Here, we report direct evidence for the evolution of U speciation over 3,300 y in naturally highly U-enriched sediments (350-760 µg ⋅ g-1 U) from Lake Nègre (Mercantour Massif, Mediterranean Alps, France) by combining U isotopic data (δ238U and (234U/238U)) with U L 3 -edge X-ray absorption fine structure spectroscopy. Constant isotopic ratios over the entire sediment core indicate stable U sources and accumulation modes, allowing for determination of the impact of aging on U speciation. We demonstrate that, after sediment deposition, mononuclear U(IV) species associated with organic matter transformed into authigenic polymeric U(IV)-silica species that might have partially converted to a nanocrystalline coffinite (UIVSiO4·nH2O)-like phase. This diagenetic transformation occurred in less than 700 y and is consistent with the high silica availability of sediments in which diatoms are abundant. It also yields consistency with laboratory studies that proposed the formation of colloidal polynuclear U(IV)-silica species, as precursors for coffinite formation. However, the incomplete transformation observed here only slightly reduces the potential lability of U, which could have important implications to evaluate the long-term management of U-contaminated sediments and, by extension, of U-bearing wastes in silica-rich subsurface environments.
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2
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Strzelecki AC, Barral T, Estevenon P, Mesbah A, Goncharov V, Baker J, Bai J, Clavier N, Szenknect S, Migdisov A, Xu H, Ewing RC, Dacheux N, Guo X. The Role of Water and Hydroxyl Groups in the Structures of Stetindite and Coffinite, MSiO 4 (M = Ce, U). Inorg Chem 2021; 60:718-735. [PMID: 33393766 DOI: 10.1021/acs.inorgchem.0c02757] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Orthosilicates adopt the zircon structure types (I41/amd), consisting of isolated SiO4 tetrahedra joined by A-site metal cations, such as Ce and U. They are of significant interest in the fields of geochemistry, mineralogy, nuclear waste form development, and material science. Stetindite (CeSiO4) and coffinite (USiO4) can be formed under hydrothermal conditions despite both being thermodynamically metastable. Water has been hypothesized to play a significant role in stabilizing and forming these orthosilicate phases, though little experimental evidence exists. To understand the effects of hydration or hydroxylation on these orthosilicates, in situ high-temperature synchrotron and laboratory-based X-ray diffraction was conducted from 25 to ∼850 °C. Stetindite maintains its I41/amd symmetry with increasing temperature but exhibits a discontinuous expansion along the a-axis during heating, presumably due to the removal of water confined in the [001] channels, which shrink against thermal expansion along the a-axis. Additional in situ high-temperature Raman and Fourier transform infrared spectroscopy also confirmed the presence of the confined water. Coffinite was also found to expand nonlinearly up to 600 °C and then thermally decompose into a mixture of UO2 and SiO2. A combination of dehydration and dehydroxylation is proposed for explaining the thermal behavior of coffinite synthesized hydrothermally. Additionally, we investigated high-temperature structures of two coffinite-thorite solid solutions, uranothorite (UxTh1-xSiO4), which displayed complex variations in composition during heating that was attributed to the negative enthalpy of mixing. Lastly, for the first time, the coefficients of thermal expansion of CeSiO4, USiO4, U0.46Th0.54SiO4, and U0.9Th0.1SiO4 were determined to be αV = 14.49 × 10-6, 14.29 × 10-6, 17.21 × 10-6, and 17.23 × 10-6 °C-1, respectively.
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Affiliation(s)
- Andrew C Strzelecki
- Department of Chemistry, Washington State University, Pullman 99164, Washington, United States.,Alexandra Navrotsky Institute for Experimental Thermodynamics, Washington State University, Pullman 99164, Washington, United States.,Materials Science and Engineering Program, Washington State University, Pullman 99164, Washington, United States
| | - Thomas Barral
- Department of Chemistry, Washington State University, Pullman 99164, Washington, United States.,Alexandra Navrotsky Institute for Experimental Thermodynamics, Washington State University, Pullman 99164, Washington, United States.,ICSM, Univ Montpellier, CNRS, CEA, ENSCM, Site de Marcoule 30207, Bagnols sur Cèze, France
| | - Paul Estevenon
- ICSM, Univ Montpellier, CNRS, CEA, ENSCM, Site de Marcoule 30207, Bagnols sur Cèze, France.,CEA, DES, ISEC, DMRC, Univ Montpellier, Site de Marcoule 30207, France
| | - Adel Mesbah
- ICSM, Univ Montpellier, CNRS, CEA, ENSCM, Site de Marcoule 30207, Bagnols sur Cèze, France
| | - Vitaliy Goncharov
- Department of Chemistry, Washington State University, Pullman 99164, Washington, United States.,Alexandra Navrotsky Institute for Experimental Thermodynamics, Washington State University, Pullman 99164, Washington, United States.,Materials Science and Engineering Program, Washington State University, Pullman 99164, Washington, United States.,Earth and Environmental Sciences Division, Los Alamos National Laboratory, Los Alamos 87545, New Mexico, United States
| | - Jason Baker
- Earth and Environmental Sciences Division, Los Alamos National Laboratory, Los Alamos 87545, New Mexico, United States
| | - Jianming Bai
- National Synchrotron Light Source II, Brookhaven National Laboratory, Upton 11973, New York, United States
| | - Nicolas Clavier
- ICSM, Univ Montpellier, CNRS, CEA, ENSCM, Site de Marcoule 30207, Bagnols sur Cèze, France
| | - Stephanie Szenknect
- ICSM, Univ Montpellier, CNRS, CEA, ENSCM, Site de Marcoule 30207, Bagnols sur Cèze, France
| | - Artaches Migdisov
- Earth and Environmental Sciences Division, Los Alamos National Laboratory, Los Alamos 87545, New Mexico, United States
| | - Hongwu Xu
- Earth and Environmental Sciences Division, Los Alamos National Laboratory, Los Alamos 87545, New Mexico, United States
| | - Rodney C Ewing
- Department of Geological Sciences, Stanford University, Stanford 94305, California, United States
| | - Nicolas Dacheux
- ICSM, Univ Montpellier, CNRS, CEA, ENSCM, Site de Marcoule 30207, Bagnols sur Cèze, France
| | - Xiaofeng Guo
- Department of Chemistry, Washington State University, Pullman 99164, Washington, United States.,Alexandra Navrotsky Institute for Experimental Thermodynamics, Washington State University, Pullman 99164, Washington, United States.,Materials Science and Engineering Program, Washington State University, Pullman 99164, Washington, United States
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3
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Strzelecki AC, Bourgeois C, Kriegsman KW, Estevenon P, Wei N, Szenknect S, Mesbah A, Wu D, Ewing RC, Dacheux N, Guo X. Thermodynamics of CeSiO 4: Implications for Actinide Orthosilicates. Inorg Chem 2020; 59:13174-13183. [PMID: 32871073 DOI: 10.1021/acs.inorgchem.0c01476] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Zircon (ZrSiO4, I41/amd) can accommodate actinides, such as thorium, uranium, and plutonium. The zircon structure has been determined for several of the end-member compositions of other actinides, such as plutonium and neptunium. However, the thermodynamic properties of these actinide zircon structure types are largely unknown due to the difficulties in synthesizing these materials and handling transuranium actinides. Thus, we have completed a thermodynamic study of cerium orthosilicate, stetindite (CeSiO4), a surrogate of PuSiO4. For the first time, the standard enthalpy of formation of CeSiO4 was obtained by high temperature oxide melt solution calorimetry to be -1971.9 ± 3.6 kJ/mol. Stetindite is energetically metastable with respect to CeO2 and SiO2 by 27.5 ± 3.1 kJ/mol. The metastability explains the rarity of the natural occurrence of stetindite and the difficulty of its synthesis. Applying the obtained enthalpy of formation of CeSiO4 from this work, along with those previously reported for USiO4 and ThSiO4, we developed an empirical energetic relation for actinide orthosilicates. The predicted enthalpies of formation of AnSiO4 are then determined with a discussion of future strategies for efficiently immobilizing Pu or minor actinides in the zircon structure.
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Affiliation(s)
- Andrew C Strzelecki
- Department of Chemistry, Washington State University, Pullman, Washington 99164, United States.,Alexandra Navrotsky Institute for Experimental Thermodynamics, Washington State University, Pullman, Washington 99164, United States.,Materials Science and Engineering, Washington State University, Pullman, Washington 99164, United States
| | - Clement Bourgeois
- Department of Chemistry, Washington State University, Pullman, Washington 99164, United States.,Alexandra Navrotsky Institute for Experimental Thermodynamics, Washington State University, Pullman, Washington 99164, United States
| | - Kyle W Kriegsman
- Department of Chemistry, Washington State University, Pullman, Washington 99164, United States.,Alexandra Navrotsky Institute for Experimental Thermodynamics, Washington State University, Pullman, Washington 99164, United States
| | - Paul Estevenon
- ICSM, Univ Montpellier, CNRS, CEA, ENSCM, Site de Marcoule, Bagnols sur Cèze 30207, France.,CEA, DES, ISEC, DMRC, Univ Montpellier, Site de Marcoule 30207, France
| | - Nian Wei
- Department of Chemistry, Washington State University, Pullman, Washington 99164, United States.,College of Physical Science and Technology, Sichuan University, Chengdu 610065, People's Republic of China
| | - Stephanie Szenknect
- ICSM, Univ Montpellier, CNRS, CEA, ENSCM, Site de Marcoule, Bagnols sur Cèze 30207, France
| | - Adel Mesbah
- ICSM, Univ Montpellier, CNRS, CEA, ENSCM, Site de Marcoule, Bagnols sur Cèze 30207, France
| | - Di Wu
- Department of Chemistry, Washington State University, Pullman, Washington 99164, United States.,Alexandra Navrotsky Institute for Experimental Thermodynamics, Washington State University, Pullman, Washington 99164, United States.,Materials Science and Engineering, Washington State University, Pullman, Washington 99164, United States.,The Gene and Linda Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, Washington 99164, United States
| | - Rodney C Ewing
- Department of Geological Sciences, Stanford University, Stanford, California 94305, United States
| | - Nicolas Dacheux
- ICSM, Univ Montpellier, CNRS, CEA, ENSCM, Site de Marcoule, Bagnols sur Cèze 30207, France
| | - Xiaofeng Guo
- Department of Chemistry, Washington State University, Pullman, Washington 99164, United States.,Alexandra Navrotsky Institute for Experimental Thermodynamics, Washington State University, Pullman, Washington 99164, United States.,Materials Science and Engineering, Washington State University, Pullman, Washington 99164, United States
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4
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Estevenon P, Causse J, Szenknect S, Welcomme E, Mesbah A, Moisy P, Poinssot C, Dacheux N. In situ study of the synthesis of thorite (ThSiO 4) under environmental representative conditions. Dalton Trans 2020; 49:11512-11521. [PMID: 32840279 DOI: 10.1039/d0dt01790f] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Thorite, (ThSiO4) with a zircon type structure, is one of the most abundant natural sources of thorium on Earth. Generally, actinides are known to form nanoparticles in silicate medium, though no direct link between those colloids and the crystalline form of thorite was evidenced until now. Here we show the formation of thorite from colloids and nanocrystalline structures under experimental conditions close to environmental pH and temperature. Through in situ small and wide angle X-ray scattering (SWAXS) measurements, colloids with a few nanometers in size were first evidenced at a low reaction time. These colloids have elongated shapes and finally tend to aggregate after their size has reached 10 nm. Once aggregated, the system goes through a maturation step, ending with the emergence of nanocrystallites as thorite zircon structures. This maturation step is longer when the reaction temperature is decreased which highlights the kinetic considerations. These results have potential implications on the paragenesis of Th mineral deposits and also in the behaviour of Th and, by analogy, tetravalent actinides in the environment. The significant characteristics of this work are that Th-silicate colloids were demonstrated at low temperatures and a near neutral pH with long-term stability and a morphology in favor of high mobility in groundwater. If these species are formed in more diluted media, this could be problematic owing to the spreading of Th and, by analogy, other tetravalent actinides in the environment.
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Affiliation(s)
- Paul Estevenon
- ICSM, Univ Montpellier, CEA, CNRS, ENSCM, Bagnols-sur-Cèze, France. and CEA, DES, ISEC, DMRC, Univ Montpellier, Marcoule, France
| | - Jeremy Causse
- ICSM, Univ Montpellier, CEA, CNRS, ENSCM, Bagnols-sur-Cèze, France.
| | | | | | - Adel Mesbah
- ICSM, Univ Montpellier, CEA, CNRS, ENSCM, Bagnols-sur-Cèze, France.
| | - Philippe Moisy
- CEA, DES, ISEC, DMRC, Univ Montpellier, Marcoule, France
| | | | - Nicolas Dacheux
- ICSM, Univ Montpellier, CEA, CNRS, ENSCM, Bagnols-sur-Cèze, France.
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Abstract
Most of the highly radioactive spent nuclear fuel (SNF) around the world is destined for final disposal in deep-mined geological repositories. At the end of the fuel's useful life in a reactor, about 96% of the SNF is still UO2. Thus, the behaviour of UO2 in SNF must be understood and evaluated under the weathering conditions of geologic disposal, which extend to periods of hundreds of thousands of years. There is ample evidence from nature that many uranium deposits have experienced conditions for which the formation of coffinite, USiO4, has been favoured over uraninite, UO2+x, during subsequent alteration events. Thus, coffinite is an important alteration product of the UO2 in SNF. Here, we present the first evidence of the formation of coffinite on the surface of UO2 at the time scale of laboratory experiments in a solution saturated with respect to amorphous silica at pH = 9, room temperature and under anoxic conditions.
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6
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Estevenon P, Welcomme E, Tamain C, Jouan G, Szenknect S, Mesbah A, Poinssot C, Moisy P, Dacheux N. The formation of PuSiO 4 under hydrothermal conditions. Dalton Trans 2020; 49:6434-6445. [PMID: 32355939 DOI: 10.1039/d0dt01183e] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Attempts to synthesize plutonium(iv) silicate, PuSiO4, have been made on the basis of results recently reported in the literature for CeSiO4, ThSiO4, and USiO4 under hydrothermal conditions. Although it was not possible to prepare PuSiO4via applying the conditions reported for thorium and uranium, an efficient method of PuSiO4 synthesis was established by applying the conditions optimized for the CeSiO4 system. This method was based on the slow oxidation of plutonium(iii) silicate reactants under hydrothermal conditions at 150 °C in hydrochloric acid (pH = 3-4). These results shed new light on the potential behavior of plutonium in reductive environments, highlighting the representative nature of cerium surrogates when studying plutonium under such conditions and providing some important pieces of information regarding plutonium chemistry in silicate solutions.
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Affiliation(s)
- Paul Estevenon
- CEA, DES, ISEC, DMRC, Univ Montpellier, Marcoule, France and ICSM, Univ Montpellier, CNRS, CEA, ENSCM, Site de Marcoule, Bagnols-sur-Cèze, France.
| | | | | | - Gauthier Jouan
- CEA, DES, ISEC, DMRC, Univ Montpellier, Marcoule, France
| | - Stephanie Szenknect
- ICSM, Univ Montpellier, CNRS, CEA, ENSCM, Site de Marcoule, Bagnols-sur-Cèze, France.
| | - Adel Mesbah
- ICSM, Univ Montpellier, CNRS, CEA, ENSCM, Site de Marcoule, Bagnols-sur-Cèze, France.
| | | | - Philippe Moisy
- CEA, DES, ISEC, DMRC, Univ Montpellier, Marcoule, France
| | - Nicolas Dacheux
- ICSM, Univ Montpellier, CNRS, CEA, ENSCM, Site de Marcoule, Bagnols-sur-Cèze, France.
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7
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Zhang L, Aksenov SM, Kokot AM, Perry SN, Olds TA, Burns PC. Crystal Chemistry and Structural Complexity of Uranium(IV) Sulfates: Synthesis of U 3H 2(SO 4) 7(H 2O) 5·3H 2O and U 3(UO 2) 0.2(SO 4) 6(OH) 0.4·2.3H 2O with Framework Structures by the Photochemical Reduction of Uranyl. Inorg Chem 2020; 59:5813-5817. [PMID: 32314904 DOI: 10.1021/acs.inorgchem.0c00385] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Two uranium(IV) sulfate framework compounds were crystallized at room temperature from aqueous solutions containing uranyl ions by photochemical reduction in the presence of 2-propanol. U3H2(SO4)7(H2O)5·3H2O (1) crystallizes in space group P65 with a = 9.3052(17) Å, c = 53.515(10) Å, V = 4012.9(13) Å3, and Z = 6, and U3(UO2)0.2(SO4)6(OH)0.4·2.3H2O (2) is tetragonal, with space group P42/nmc, a = 25.624(3) Å, c = 8.9435(10) Å, V = 5872.2(11) Å3, and Z = 8. The structures of 1 and 2 are the most complex among uranium(IV) sulfates.
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8
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Mondal SK, Das PK, Mandal N, Arya A. A novel approach to the structural distortions of U/Th snub-disphenoids and their control on zircon → reidite type phase transitions of U 1-x Th x SiO 4. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2020; 32:145401. [PMID: 31825899 DOI: 10.1088/1361-648x/ab60e4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Coffinite (USiO4) and thorite (ThSiO4) are conspicuous radiogenic silicates in the geonomy. They form U1-x Th x SiO4 (uranothorite) solid solutions in zircon-type phase. Investigating the phase-evolution of these minerals is of utmost significance in realizing their applicability in the front-as well as at the back-end of nuclear industries. We carried out a systematic study of zircon- to reidite-type (tetragonal I41/amd to I41/a) structural transitions of U1-x Th x SiO4 solid solution, and investigated their mechanical behaviour. We found a unique behaviour of transition pressure with the change in U-Th concentration in the solid solution. The phase transition pressure (p t) is found to be minimum for x = 0.5. We develop the necessary formalism and present an efficient method to estimate the longitudinal and angular distortions of U/ThO8-triangular dodecahedra (snub-disphenoids). We have parameterized two new factors: δ (longitudinal distortions) and σ 2 (angular distortions) to quantify the polyhedral distortions. A detailed analysis of U/ThO8 snub-disphenoidal distortions is presented to address such variation of p t with U and Th concentration. We argue that our approach is independent of polyhedral volume and can be used for any AB8 (A: cation, B: anion) type snub-disphenoidal system.
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Affiliation(s)
- Sudip Kumar Mondal
- Department of Physics, Jadavpur University, Kolkata 700032, India. Faculty of Science, High Pressure and Temperature Laboratory, Jadavpur University, Kolkata 700032, India
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9
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Ghadiri A, Abdollahy M, Khanchi A, Khalesi MR, Akbari M. Synthesis and Characterization of Thorite Nanoparticles by Hydrothermal Method. RUSS J INORG CHEM+ 2020. [DOI: 10.1134/s0036023619140122] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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10
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Loreggian L, Novotny A, Bretagne SL, Bartova B, Wang Y, Bernier-Latmani R. Effect of Aging on the Stability of Microbially Reduced Uranium in Natural Sediment. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:613-620. [PMID: 31769664 DOI: 10.1021/acs.est.8b07023] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Reductive immobilization of uranium has been explored as a remediation strategy for the U-contaminated subsurface. Via the in situ biostimulation of microbial processes, hexavalent U is reduced to less soluble tetravalent species, which are immobilized within the sediment. Although the mineral uraninite (UO2) was initially considered the dominant product of biological reduction, non-crystalline U(IV) species (NCU(IV)) are found to be abundant in the environment despite their greater susceptibility to oxidation and remobilization. However, it has been recently proposed that, through aging, NCU(IV) might transform into UO2, which would potentially enhance the stability of the reduced U pool. In this study, we performed column experiments to produce NCU(IV) species in natural sediment mimicking the environmental conditions during bioremediation. Bioreduced sediment retrieved from the columns and harboring NCU(IV) was incubated in static microcosms under anoxic conditions to allow the systematic monitoring of U coordination by X-ray absorption spectroscopy (XAS) over 12 months. XAS revealed that, under the investigated conditions, the speciation of U(IV) does not change over time. Thus, because NCU(IV) is the dominant species in the sediment, bioreduced U(IV) species remain vulnerable to oxidation and remobilization in the aqueous phase even after a 12-month aging period.
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Affiliation(s)
- Luca Loreggian
- Environmental Microbiology Laboratory (EML), EPFL-ENAC-IIE-EML, Ecole Polytechnique Federale de Lausanne (EPFL), Station 6, CH-1015 Lausanne, Switzerland
| | - Agnes Novotny
- Environmental Microbiology Laboratory (EML), EPFL-ENAC-IIE-EML, Ecole Polytechnique Federale de Lausanne (EPFL), Station 6, CH-1015 Lausanne, Switzerland
| | - Sophie Louise Bretagne
- Environmental Microbiology Laboratory (EML), EPFL-ENAC-IIE-EML, Ecole Polytechnique Federale de Lausanne (EPFL), Station 6, CH-1015 Lausanne, Switzerland
| | - Barbora Bartova
- Environmental Microbiology Laboratory (EML), EPFL-ENAC-IIE-EML, Ecole Polytechnique Federale de Lausanne (EPFL), Station 6, CH-1015 Lausanne, Switzerland
| | - Yuheng Wang
- School of Ecology and Environment, Northwestern Polytechnical University, 710129 Xi'an, P. R. China
| | - Rizlan Bernier-Latmani
- Environmental Microbiology Laboratory (EML), EPFL-ENAC-IIE-EML, Ecole Polytechnique Federale de Lausanne (EPFL), Station 6, CH-1015 Lausanne, Switzerland
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11
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Liu Q, Yin H, Bao H, Yue Z, Diefenbach K, Tang Z, Lin J, Wang JQ. Insights into the new 3d–5f heterometallic quaternary fluorides: Synthesis, crystal structures, spectroscopic properties, and thermodynamic stability. Inorganica Chim Acta 2019. [DOI: 10.1016/j.ica.2018.12.038] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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12
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Estevenon P, Welcomme E, Szenknect S, Mesbah A, Moisy P, Poinssot C, Dacheux N. Multiparametric Study of the Synthesis of ThSiO4 under Hydrothermal Conditions. Inorg Chem 2018; 57:9393-9402. [DOI: 10.1021/acs.inorgchem.8b01390] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Paul Estevenon
- CEA, Nuclear Energy Division, CEA Marcoule, Research Department of Mining and Fuel Recycling Processes, DEN/DMRC, BP 17171, 30207 Bagnols-sur-Cèze, France
| | - Eleonore Welcomme
- CEA, Nuclear Energy Division, CEA Marcoule, Research Department of Mining and Fuel Recycling Processes, DEN/DMRC, BP 17171, 30207 Bagnols-sur-Cèze, France
| | - Stephanie Szenknect
- ICSM, CEA, CNRS, ENSCM, Univ Montpellier, Site de Marcoule,
Bât. 426, BP 17171, 30207 Bagnols-sur-Cèze, France
| | - Adel Mesbah
- ICSM, CEA, CNRS, ENSCM, Univ Montpellier, Site de Marcoule,
Bât. 426, BP 17171, 30207 Bagnols-sur-Cèze, France
| | - Philippe Moisy
- CEA, Nuclear Energy Division, CEA Marcoule, Research Department of Mining and Fuel Recycling Processes, DEN/DMRC, BP 17171, 30207 Bagnols-sur-Cèze, France
| | - Christophe Poinssot
- CEA, Nuclear Energy Division, CEA Marcoule, Research Department of Mining and Fuel Recycling Processes, DEN/DMRC, BP 17171, 30207 Bagnols-sur-Cèze, France
| | - Nicolas Dacheux
- ICSM, CEA, CNRS, ENSCM, Univ Montpellier, Site de Marcoule,
Bât. 426, BP 17171, 30207 Bagnols-sur-Cèze, France
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13
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Lin J, Yue Z, Silver MA, Qie M, Wang X, Liu W, Lin X, Bao HL, Zhang LJ, Wang S, Wang JQ. In Situ Reduction from Uranyl Ion into a Tetravalent Uranium Trimer and Hexamer Featuring Ion-Exchange Properties and the Alexandrite Effect. Inorg Chem 2018; 57:6753-6761. [DOI: 10.1021/acs.inorgchem.8b01098] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Jian Lin
- Shanghai Institute of Applied Physics, Chinese Academy of Sciences, 2019 Jia Luo Road, Shanghai 201800, China
| | - Zenghui Yue
- Shanghai Institute of Applied Physics, Chinese Academy of Sciences, 2019 Jia Luo Road, Shanghai 201800, China
- University of Chinese Academy of Sciences, No.19(A) Yuquan Road, Shijingshan District, Beijing 100049, China
- Shanghai Synchrotron Radiation Facility, Shanghai Institute of Applied of Physics Chinese Academy of Sciences, Zhangheng Road 239, Pudong, Shanghai 201204, China
| | - Mark A. Silver
- School for Radiological and Interdisciplinary Sciences (RAD-X) and Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Soochow University, 199 Ren’ai Road, Suzhou 215123, China
| | - Meiying Qie
- Shanghai Institute of Applied Physics, Chinese Academy of Sciences, 2019 Jia Luo Road, Shanghai 201800, China
- University of Chinese Academy of Sciences, No.19(A) Yuquan Road, Shijingshan District, Beijing 100049, China
| | - Xiaomei Wang
- Shanghai Institute of Applied Physics, Chinese Academy of Sciences, 2019 Jia Luo Road, Shanghai 201800, China
- University of Chinese Academy of Sciences, No.19(A) Yuquan Road, Shijingshan District, Beijing 100049, China
| | - Wei Liu
- School for Radiological and Interdisciplinary Sciences (RAD-X) and Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Soochow University, 199 Ren’ai Road, Suzhou 215123, China
| | - Xiao Lin
- Shanghai Institute of Applied Physics, Chinese Academy of Sciences, 2019 Jia Luo Road, Shanghai 201800, China
| | - Hong-Liang Bao
- Shanghai Institute of Applied Physics, Chinese Academy of Sciences, 2019 Jia Luo Road, Shanghai 201800, China
| | - Lin-Juan Zhang
- Shanghai Institute of Applied Physics, Chinese Academy of Sciences, 2019 Jia Luo Road, Shanghai 201800, China
| | - Shuao Wang
- School for Radiological and Interdisciplinary Sciences (RAD-X) and Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Soochow University, 199 Ren’ai Road, Suzhou 215123, China
| | - Jian-Qiang Wang
- Shanghai Institute of Applied Physics, Chinese Academy of Sciences, 2019 Jia Luo Road, Shanghai 201800, China
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14
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Mesbah A, Clavier N, Lozano-Rodriguez MJ, Szenknect S, Dacheux N. Incorporation of Thorium in the Zircon Structure Type through the Th 1-xEr x(SiO 4) 1-x(PO 4) x Thorite-Xenotime Solid Solution. Inorg Chem 2016; 55:11273-11282. [PMID: 27749037 DOI: 10.1021/acs.inorgchem.6b01862] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Pure powdered compounds with a general formula Th1-xErx(SiO4)1-x(PO4)x belonging to the zircon-xenotime family were successfully synthesized under hydrothermal conditions (250 °C, 7 days) as recently reported for the preparation of coffinite. Therefore, a thorough, combined PXRD, EDX, EXAFS, Raman, and FTIR analysis showed the formation of a solid solution in agreement with Vegard's law. Moreover, the examination of the local structure shows that the Th-O distances remain close to those found in ThSiO4, whereas the Er-O distances show a significant decrease from 2.38(14) to 2.34(7) Å when increasing the erbium content from x = 0.2 to x = 1. The variation of the local structure also affects the PO43- groups that are surely distorted in the structure.
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Affiliation(s)
- Adel Mesbah
- ICSM, UMR 5257 CEA/CNRS/ENSCM/University of Montpellier , Site de Marcoule-Bât. 426, BP 17171, 30207 Bagnols-sur-Cèze cedex, France
| | - Nicolas Clavier
- ICSM, UMR 5257 CEA/CNRS/ENSCM/University of Montpellier , Site de Marcoule-Bât. 426, BP 17171, 30207 Bagnols-sur-Cèze cedex, France
| | - M Janeth Lozano-Rodriguez
- HZDR, Institute of Resource Ecology, The Rossendorf Beamline at ESRF , P.O. Box 220, 38043 Grenoble, France
| | - Stephanie Szenknect
- ICSM, UMR 5257 CEA/CNRS/ENSCM/University of Montpellier , Site de Marcoule-Bât. 426, BP 17171, 30207 Bagnols-sur-Cèze cedex, France
| | - Nicolas Dacheux
- ICSM, UMR 5257 CEA/CNRS/ENSCM/University of Montpellier , Site de Marcoule-Bât. 426, BP 17171, 30207 Bagnols-sur-Cèze cedex, France
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15
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Zänker H, Weiss S, Hennig C, Brendler V, Ikeda‐Ohno A. Oxyhydroxy Silicate Colloids: A New Type of Waterborne Actinide(IV) Colloids. ChemistryOpen 2016; 5:174-182. [PMID: 27957406 PMCID: PMC5130165 DOI: 10.1002/open.201500207] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Revised: 02/26/2016] [Indexed: 11/10/2022] Open
Abstract
At the near-neutral and reducing aquatic conditions expected in undisturbed ore deposits or in closed nuclear waste repositories, the actinides Th, U, Np, and Pu are primarily tetravalent. These tetravalent actinides (AnIV) are sparingly soluble in aquatic systems and, hence, are often assumed to be immobile. However, AnIV could become mobile if they occur as colloids. This review focuses on a new type of AnIV colloids, oxyhydroxy silicate colloids. We herein discuss the chemical characteristics of these colloids and the potential implication for their environmental behavior. The binary oxyhydroxy silicate colloids of AnIV could be potentially more mobile as a waterborne species than the well-known mono-component oxyhydroxide colloids.
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Affiliation(s)
- Harald Zänker
- Institute of Resource EcologyHelmholtz-Zentrum Dresden-RossendorfP.O. Box 51 01 1901314DresdenGermany
| | - Stephan Weiss
- Institute of Resource EcologyHelmholtz-Zentrum Dresden-RossendorfP.O. Box 51 01 1901314DresdenGermany
| | - Christoph Hennig
- Institute of Resource EcologyHelmholtz-Zentrum Dresden-RossendorfP.O. Box 51 01 1901314DresdenGermany
| | - Vinzenz Brendler
- Institute of Resource EcologyHelmholtz-Zentrum Dresden-RossendorfP.O. Box 51 01 1901314DresdenGermany
| | - Atsushi Ikeda‐Ohno
- Institute of Resource EcologyHelmholtz-Zentrum Dresden-RossendorfP.O. Box 51 01 1901314DresdenGermany
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16
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Mesbah A, Szenknect S, Clavier N, Lozano-Rodriguez J, Poinssot C, Den Auwer C, Ewing RC, Dacheux N. Coffinite, USiO4, Is Abundant in Nature: So Why Is It So Difficult To Synthesize? Inorg Chem 2015; 54:6687-96. [PMID: 26145720 DOI: 10.1021/ic502808n] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Coffinite, USiO4, is the second most abundant U(4+) mineral on Earth, and its formation by the alteration of the UO2 in spent nuclear fuel in a geologic repository may control the release of radionuclides to the environment. Despite its abundance in nature, the synthesis and characterization of coffinite have eluded researchers for decades. On the basis of the recent synthesis of USiO4, we can now define the experimental conditions under which coffinite is most efficiently formed. Optimal formation conditions are defined for four parameters: pH, T, heating time, and U/Si molar ratio. The adjustment of pH between 10 and 12 leads probably to the formation of a uranium(IV) hydroxo-silicate complex that acts as a precursor of uranium(IV) silicate colloids and then of coffinite. Moreover, in this pH range, the largest yield of coffinite formation (as compared with those of the two competing byproduct phases, nanometer-scale UO2 and amorphous SiO2) is obtained for 250 °C, 7 days, and 100% excess silica.
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Affiliation(s)
- Adel Mesbah
- †ICSM, UMR 5257 CEA/CNRS/UM/ENSCM, Site de Marcoule-Bât. 426, BP 17171, 30207 Bagnols-sur-Cèze cedex, France
| | - Stephanie Szenknect
- †ICSM, UMR 5257 CEA/CNRS/UM/ENSCM, Site de Marcoule-Bât. 426, BP 17171, 30207 Bagnols-sur-Cèze cedex, France
| | - Nicolas Clavier
- †ICSM, UMR 5257 CEA/CNRS/UM/ENSCM, Site de Marcoule-Bât. 426, BP 17171, 30207 Bagnols-sur-Cèze cedex, France
| | - Janeth Lozano-Rodriguez
- ⊥HZDR, Institute of Resource Ecology, Rossendorf Beamline at ESRF, P.O. Box 220, 38043 Grenoble, France
| | - Christophe Poinssot
- ‡CEA, Nuclear Energy Division, DRCP/DIR, CEA Marcoule, Bât. 400, BP 17171, 30207 Bagnols-sur-Cèze cedex, France
| | - Christophe Den Auwer
- ∥ICN, UMR 7272, Nice Sophia-Antipolis University, 28 av. de Valrose, 06108 Nice cedex 2, France
| | | | - Nicolas Dacheux
- †ICSM, UMR 5257 CEA/CNRS/UM/ENSCM, Site de Marcoule-Bât. 426, BP 17171, 30207 Bagnols-sur-Cèze cedex, France
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17
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Abstract
Coffinite, USiO4, is an important U(IV) mineral, but its thermodynamic properties are not well-constrained. In this work, two different coffinite samples were synthesized under hydrothermal conditions and purified from a mixture of products. The enthalpy of formation was obtained by high-temperature oxide melt solution calorimetry. Coffinite is energetically metastable with respect to a mixture of UO2 (uraninite) and SiO2 (quartz) by 25.6 ± 3.9 kJ/mol. Its standard enthalpy of formation from the elements at 25 °C is -1,970.0 ± 4.2 kJ/mol. Decomposition of the two samples was characterized by X-ray diffraction and by thermogravimetry and differential scanning calorimetry coupled with mass spectrometric analysis of evolved gases. Coffinite slowly decomposes to U3O8 and SiO2 starting around 450 °C in air and thus has poor thermal stability in the ambient environment. The energetic metastability explains why coffinite cannot be synthesized directly from uraninite and quartz but can be made by low-temperature precipitation in aqueous and hydrothermal environments. These thermochemical constraints are in accord with observations of the occurrence of coffinite in nature and are relevant to spent nuclear fuel corrosion.
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