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237 results on '"Département de recherche sur les technologies pour l'enrichissement, le démantèlement et les déchets (DE2D)"'

1. Influence of Magnesium on the Structure of Complex Multicomponent Silicates: Insights from Molecular Simulations and Neutron Scattering Experiments

Author: Nicolas Bisbrouck, Matthieu Micoulaut, Stéphane Gin, J.M. Delaye, M. Bertani, Frédéric Angeli, Thibault Charpentier, Département de recherche sur les technologies pour l'enrichissement, le démantèlement et les déchets (DE2D), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Laboratoire de Physique Théorique de la Matière Condensée (LPTMC), Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU), Laboratoire Structure et Dynamique par Résonance Magnétique (LCF) (LSDRM), Nanosciences et Innovation pour les Matériaux, la Biomédecine et l'Energie (ex SIS2M) (NIMBE UMR 3685), Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Département de recherche sur les Procédés et Matériaux pour les Environnements complexes (DPME), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Rayonnement Matière de Saclay (IRAMIS), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Materials science, Magnesium, chemistry.chemical_element, [CHIM.MATE]Chemical Sciences/Material chemistry, 02 engineering and technology, Neutron scattering, 021001 nanoscience & nanotechnology, Radial distribution function, Alkali metal, 01 natural sciences, Dissociation (chemistry), Surfaces, Coatings and Films, Molecular dynamics, chemistry, Chemical physics, 0103 physical sciences, Materials Chemistry, Physical and Theoretical Chemistry, 010306 general physics, 0210 nano-technology, Boron, Structure factor
Abstract: International audience; A series of multicomponent glasses containing up to five oxides are studied using classical molecular dynamics simulations and neutron scattering experiments. The focus is on the role of magnesium in determining the structural properties of these glasses and the possible mixed effect during a sodium/magnesium substitution. Calculated structure functions (pair correlation function and structure factor) rather accurately reproduce their experimental counterpart, and we show that more fine structural features are qualitatively reproduced well, despite some discrepancies in the preferential spatial distribution between sodium and magnesium to aluminum and boron, as well as the nonbridging oxygen, distribution. The simulated systems offer a solid basis to support previous experimental findings on the composition–structure relationship, allowing for further analysis and property calculation. It is confirmed that the substitution of sodium by magnesium leads to the decrease of four-fold boron and a modification of the alkali coordinations with a significant change of the network structure. Specifically, magnesium coordination extracted from numerical simulations highlights a potential dissociation from penta- to tetra- and hexahedral units with increasing MgO contents along the glass series, which could not be resolved experimentally.
Published: 2021

2. Effects of complex irradiation scenarios on ISG nuclear glass long-term behavior

Author: GILLET, Célia, Tribet, Magaly, Szenknect, Stephanie, ARENA, Hélène, Miro, Sandrine, Peuget, Sylvain, Laboratoire des Matériaux et Procédés Actifs (LMPA), Département de recherche sur les Procédés et Matériaux pour les Environnements complexes (DPME), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Institut de Chimie Séparative de Marcoule (ICSM - UMR 5257), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), CEA, Contributeur MAP, Département de recherche sur les technologies pour l'enrichissement, le démantèlement et les déchets (DE2D), and Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)
Subjects: [CHIM] Chemical Sciences, [CHIM]Chemical Sciences
Abstract: International audience; Several countries have chosen the recycling of U and Pu in MOX fuels associated to the vitrification of the ultimate wastes composed of fission products (FP) and minor actinides (MA) in silicate glasses. In France, the borosilicate glass known as R7T7 is currently used to confine high-level radioactive waste remaining after reprocessing of spent nuclear fuel, in the perspective of the disposal of the glass canisters in a geological repository. The main challenge is therefore to predict their long-term behavior to ensure the safety of the disposal solution: the glass physical and chemical stabilities over geological timescale must thus be demonstrated, which require to study the glass response to the radiations emitted by the nuclear waste together with its behavior when submitted to water dissolution.This work focuses on the leaching behavior of a chemically simplified borosilicate glass, chosen by the international community, (called ISG as International Simple Glass). Pristine glass coupons were subjected to several external irradiations scenarios (electrons, Au ions, electrons followed by Au ions) to simulate the various irradiation sources of a real radioactive glass, inducing electronic and/or nuclear interactions. For both electron and Au ions irradiations, the doses values have been chosen to induce significant structural and properties evolutions in the glass and they also correspond to the dose level expected under disposal condition when the water will arrive in contact with the glass. Radiation effects on the glass structure and properties have been studied by respectively Raman and NMR spectroscopies, X-ray reflectivity, density, Vickers microindentation hardness and contact angle measurements.Pristine and irradiated glass coupons were then leached for several months in pure water, at 90 °C and at a high surface-area-to-volume ratio (SA/V = 200 cm-1), in order to quickly reach the residual alteration rate regime expected on the long-term under disposal conditions. The alteration layer thickness was monitored by ToF-SIMS to calculate the glass dissolution rate and cryo-TEM was perform to describe the alteration layer nanostructure.The results showed that the electron irradiation induces only small changes of both the structure and properties of the glass, including its alteration behavior. However, the irradiation by Au ions induces significant modifications of ISG glass structure and properties, together with an increase of the glass alteration rate. The results obtained for the sequentially (electrons followed by Au ions) irradiated glass are close to those obtained on the glass irradiated with Au ions only. It suggests that the long term glass leaching is sensitive to the resulting structural changes in the glass caused by the nuclear damage, induced here by Au ions.
Published: 2022

3. Impact of magnesium on the structure of aluminoborosilicate glasses: A solid‐state NMR and Raman spectroscopy study

Author: Stéphane Gin, J.M. Delaye, Frédéric Angeli, Nicolas Bisbrouck, Dominique de Ligny, Marco Bertani, Thibault Charpentier, Matthieu Micoulaut, Département de recherche sur les technologies pour l'enrichissement, le démantèlement et les déchets (DE2D), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Laboratoire Structure et Dynamique par Résonance Magnétique (LCF) (LSDRM), Nanosciences et Innovation pour les Matériaux, la Biomédecine et l'Energie (ex SIS2M) (NIMBE UMR 3685), Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Department of Materials Science and Engineering, Institute I, Friedrich-Alexander Universität Erlangen-Nürnberg (FAU), Friedrich-Alexander Universität Erlangen-Nürnberg (FAU), Laboratoire de Physique Théorique de la Matière Condensée (LPTMC), Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU), Département de recherche sur les Procédés et Matériaux pour les Environnements complexes (DPME), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), and Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)
Subjects: inorganic chemicals, Oxygen-17, Materials science, Magnesium, Borosilicate glass, chemistry.chemical_element, [CHIM.MATE]Chemical Sciences/Material chemistry, 02 engineering and technology, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, 0104 chemical sciences, symbols.namesake, Solid-state nuclear magnetic resonance, chemistry, Materials Chemistry, Ceramics and Composites, symbols, Physical chemistry, 0210 nano-technology, Raman spectroscopy
Abstract: International audience; Seven magnesium-containing aluminoborosilicate glasses, with three to five oxides, have been studied through comprehensive multi-nuclear solid-state NMR (11B, 27Al, 29Si, 23Na, 17O and 25Mg) and Raman spectroscopy. The progressive addition of cations and the substitution of sodium and calcium by magnesium illuminate the impact of magnesium on the glass structure. The proportion of tri-coordinated boron drastically increased with magnesium addition, demonstrating the poor charge-compensating capabilities of magnesium in tetrahedral boron units. Oxygen-17NMR showed the formation of mixing sites containing both Na and Mg near non-bridging oxygen sites. Furthermore, a high magnesium content appears to result in the formation of two sub-networks (boron and silicon rich) with different polymerization degrees as well as to promote the formation of high-coordination aluminium sites (Al[V] and Al[VI]). Finally, magnesium coordination ranging from four to six, with a mean value shifting from five to six along the series, suggests that magnesium might endorse an intermediate role in these glasses.
Published: 2021

4. Atomic Insights into the Events Governing the Borosilicate Glass–Water Interface

Author: Stéphane Gin, J.M. Delaye, Rodolphe Pollet, Hicham Jabraoui, Thibault Charpentier, Laboratoire Structure et Dynamique par Résonance Magnétique (LCF) (LSDRM), Nanosciences et Innovation pour les Matériaux, la Biomédecine et l'Energie (ex SIS2M) (NIMBE UMR 3685), Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Département de recherche sur les technologies pour l'enrichissement, le démantèlement et les déchets (DE2D), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Programmes Transversaux de Compétences ≪Simulation Numérique≫ (ALTERVER) of the French Alternative Energies and Atomic Energy Commission (CEA), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), and Département de recherche sur les Procédés et Matériaux pour les Environnements complexes (DPME)
Subjects: Materials science, Interface (Java), Borosilicate glass, [CHIM.MATE]Chemical Sciences/Material chemistry, 02 engineering and technology, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, 0104 chemical sciences, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, General Energy, Chemical engineering, Degradation (geology), Physical and Theoretical Chemistry, 0210 nano-technology
Abstract: International audience; An atomistic understanding of the mechanisms that govern the borosilicate glass–water interface is highly needed to obtain initial assessments of the phenomena occurring during the degradation of nuclear waste forms. To this end, we have simulated a structural model of sodium borosilicate glass using classical molecular dynamics (CMD) simulations followed by a Car–Parrinello ab initio molecular dynamics (AIMD) simulation and periodic density functional theory (DFT) calculations to study both the reactivity and water adsorption events on a sodium borosilicate glass. The obtained results revealed that: (i) Na+ ions are directly involved in the first stages of the dissolution mechanism, namely, the penetration of water and the release of the most accessible sodium from the surface of the glass to the aqueous solution, (ii) due to the presence of a higher amount of sodium ions closer to BIV than BIII units, the boron atom with the BIII unit is more accessible to accommodate water molecules than the one with the BIV unit, and (iii) the attack of BIII by a water molecule occurs by a phenomenon of nondissociative adsorption followed by dissociative adsorption where the adsorbed water dissociates by the presence of another nearby water molecule. An analysis of the electronic structure, based on maximally localized Wannier functions, shows that the nondissociative adsorption presents a noncovalent bond between one of the lone pairs of the water molecule and BIII (B–OH2) by an interatomic distance of 1.57 Å, whereas the dissociative adsorption of this water molecule showed a B–OH covalent bond by an interatomic distance of 1.49 Å. Water molecules are collectively adsorbed on a B adsorption site, which ultimately leads to terminal B–OH and silanol H–NBO formations. As B–OH is formed, the boron site begins to attract more water molecules, which can be considered an early stage of solvation of the glass around this site. By combining DFT approaches and Bader charge analysis, our calculation reports that the adsorption of a single water molecule onto a sodium-rich site exhibits higher total interaction energy than onto a pure boron atomic site. On the other hand, DFT revealed that the water molecule adsorbed on the sodium-rich site exhibits a higher elongation of the H–OW bond length of about 0.05 Å, indicating the high probability of water dissociation and favoring the formation of H–NBO precipitates.
Published: 2021

5. Inferring bubble volume fraction in a glass melt through in situ impedance spectroscopy measurements

Author: Annabelle Laplace, Luiz Pereira, Rafael Bianchini Nuernberg, Muriel Neyret, Franck Pigeonneau, Département de recherche sur les technologies pour l'enrichissement, le démantèlement et les déchets (DE2D), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Institut des Sciences et technologies pour une Economie Circulaire des énergies bas carbone (ISEC), Centre de Mise en Forme des Matériaux (CEMEF), MINES ParisTech - École nationale supérieure des mines de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Département de recherche sur les Procédés et Matériaux pour les Environnements complexes (DPME), and Mines Paris - PSL (École nationale supérieure des mines de Paris)
Subjects: 010302 applied physics, impedance spectroscopy, Materials science, Borosilicate glass, bubble, Bubble, Analytical chemistry, [CHIM.MATE]Chemical Sciences/Material chemistry, 02 engineering and technology, [CHIM.INOR]Chemical Sciences/Inorganic chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, Dielectric spectroscopy, Volume (thermodynamics), Electrical resistivity and conductivity, glass melt, Phase (matter), 0103 physical sciences, Volume fraction, ionic conductivity, General Materials Science, Sample preparation, 0210 nano-technology
Abstract: International audience; We evaluated the feasibility of inferring the bubble volume fraction (b) in a melt by employing in situ impedance spectroscopy measurements. This idea stems from the effective medium theory, in which the ionic conductivity of a biphasic material can be determined from the isolated contribution of each constituent phase and their respective volumetric content. Therefore, we investigated the overall electrical conductivity of a borosilicate melt doped with cerium-IV oxide at a constant temperature (1273 K), in which O2 gas production takes place. To validate the use of this proposed technique, post-mortem bubble volume fraction analyses on samples synthesized following the same procedure were conducted by apparent density and impedance spectroscopy measurements at low temperatures (below Tg). A comparison of these post-mortem and in situ techniques is presented. Despite some discrepancies observed between the bubble volume fractions estimated by these different methods, the main results demonstrate the technical viability of this in situ approach. In situ impedance spectroscopy presents advantages in terms of presynthesis duration, sample preparation, and the information is obtained at high temperatures, eliminating the possible influence of the cooling stage.
Published: 2021

6. Comparing hexacyanoferrate loaded onto silica, silicotitanate and chabazite sorbents for Cs extraction with a continuous-flow fixed-bed setup: Methods and pitfalls

Author: Thierry Prevost, Agnès Grandjean, Eric Louradour, Virginie Fremy, Audrey Hertz, Jérémy Mascarade, Yves Barré, Département de recherche sur les technologies pour l'enrichissement, le démantèlement et les déchets (DE2D), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), CTI, ALSYS Group,(France), ORANO, ANR-11-RSNR-0005,DEMETERRES,Développement de Méthodes bio-et Eco-Technologiques pour la Remédiation Raisonnée des Effluents et des Sols en appui à une stratégie de réhabilitation agricole post-accidentelle(2011), and Département de recherche sur les Procédés et Matériaux pour les Environnements complexes (DPME)
Subjects: Chabazite, Environmental Engineering, Materials science, Sorbent, Continuous flow, Fixed bed, General Chemical Engineering, Extraction (chemistry), [CHIM.MATE]Chemical Sciences/Material chemistry, 02 engineering and technology, Human decontamination, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, 0104 chemical sciences, Broad spectrum, Chemical engineering, Environmental Chemistry, [SPI.GPROC]Engineering Sciences [physics]/Chemical and Process Engineering, 0210 nano-technology, Safety, Risk, Reliability and Quality
Abstract: International audience; Radioactive 137Cs is one of the most common and problematic radionuclides in nuclear wastes. Decontamination typically involves passing the waste in continuous flow through an agitated or fixed bed reactor containing an efficient sorbent. There are many articles in the literature describing a broad spectrum of highly efficient sorbents. However, comparing their properties is often difficult, mainly because the experimental conditions used differ. We describe the series of experiments that need to be performed to characterize Cs sorbents and illustrate by comparing three of these that, for the extraction of trace elements, the kinetics and selectivity of the exchange process are far more important than the maximum extraction capacity of the material.
Published: 2020

7. The role of alkalis on the incorporation of iodine in simple borosilicate glasses

Author: Thibault Charpentier, Jean-Luc Dussossoy, Michael J. Toplis, Mélanie Moskura, Lionel Campayo, Boris Vénague, Département de recherche sur les Procédés et Matériaux pour les Environnements complexes (DPME), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Laboratoire Structure et Dynamique par Résonance Magnétique (LCF) (LSDRM), Nanosciences et Innovation pour les Matériaux, la Biomédecine et l'Energie (ex SIS2M) (NIMBE UMR 3685), Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Département de recherche sur les technologies pour l'enrichissement, le démantèlement et les déchets (DE2D), Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Institut Rayonnement Matière de Saclay (IRAMIS), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)
Subjects: 010302 applied physics, chemistry.chemical_classification, Glass structure, Absorption spectroscopy, Borosilicate glass, Iodide, Inorganic chemistry, chemistry.chemical_element, 02 engineering and technology, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Iodine, Alkali metal, 01 natural sciences, Electronic, Optical and Magnetic Materials, chemistry, 0103 physical sciences, Materials Chemistry, Ceramics and Composites, Composition (visual arts), 0210 nano-technology
Abstract: International audience; To understand the influence of alkali elements on the incorporation mechanisms and incorporation limit of iodine in borosilicate glasses used for nuclear waste immobilization, series of model glasses with different alkali contents (22 or 35 mol% Na2O, or 22 mol% of a mixture of alkalis: Na substituted by Li, K and Cs) were loaded with iodine (from 1 000 to 10 000 ppm at. under the form of iodide) at 1100 °C. When the incorporation limit of iodine was reached, alkali iodide crystals were observed (e.g., NaI). For oversaturated samples containing two alkalis, iodide crystals were analyzed and it was found that crystals are enriched in the heavier one of the two relative to bulk composition. Crystal-free glasses were studied by Electron Probe Micro-Analysis to measure the incorporation limit of iodine. A complex variation of incorporation limit was found. Initial substitution of Na by other alkalis (50%, only the potassium-bearing system could be studied. In this case, the incorporation limit was non-linear and passed through a minimum for a substitution of ∼75%. Glass structure was determined by X-Ray absorption spectroscopy and Nuclear Magnetic Resonance, providing evidence for local I environments rich in alkalis. It is concluded that high alkali content and high concentrations of Na2O are particularly favorable for iodine incorporation.
Published: 2022

8. Study of the volatilization of Cesium and Rhenium in the waste vitrification process

Author: Sophie Schuller, Alain Ledoux, Thomas Charpin, Dominique Thomas, Caroline Michel, Laboratoire de Développement des Procédés de Vitrification (LDPV), Département de recherche sur les technologies pour l'enrichissement, le démantèlement et les déchets (DE2D), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Laboratoire Réactions et Génie des Procédés (LRGP), Centre National de la Recherche Scientifique (CNRS)-Université de Lorraine (UL), Département de recherche sur les Procédés et Matériaux pour les Environnements complexes (DPME), and Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Nuclear and High Energy Physics, Materials science, particle, aerosol, chemistry.chemical_element, Scrubber, 02 engineering and technology, rhenium, [CHIM.INOR]Chemical Sciences/Inorganic chemistry, 010403 inorganic & nuclear chemistry, 01 natural sciences, [CHIM.GENI]Chemical Sciences/Chemical engineering, Phase (matter), cesium, [CHIM.CRIS]Chemical Sciences/Cristallography, General Materials Science, Vitrification, waste, [SPI.GPROC]Engineering Sciences [physics]/Chemical and Process Engineering, volatilization, Volatilisation, [CHIM.MATE]Chemical Sciences/Material chemistry, Rhenium, 021001 nanoscience & nanotechnology, vitrification, 0104 chemical sciences, Aerosol, Nuclear Energy and Engineering, chemistry, Chemical engineering, 13. Climate action, Caesium, Particle, technetium, 0210 nano-technology
Abstract: International audience; A side effect of high level waste vitrification at 1100°C is the volatilization of radioactive cesium (Cs), recaptured further on in the process as a solid aerosol by a dust scrubber. Feedback from industry suggests that Cs combines with technetium (Tc) █ simulated here by rhenium (Re), chosen for its similar behavior █ to form volatile species. This work characterized Cs volatilization and aerosol formation. The first experiment involved elaborating and analyzing a simplified glass enriched with Cs and Re, which reinforce the volatilization phenomena. The results showed that a demixed liquid phase rich in Cs, Re, Mo, and Na formed in the liquid melt, which is reminiscent of a molybdic phase evoked in the literature. Moreover, analyzing the condensed gases led to the conclusion that the alkalis and Re volatilize congruently at around 700°C. In the second experiment, a series of measurements of the gas phase characterized aerosols throughout the process. The size distribution results showed that the particles formed in the furnace were mostly submicronic, and that the aerosols in the calciner and the dust scrubber included nanoparticles and micronic particles. SEM-EDS characterization revealed the composition of a spherical particle from the furnace made of two nested phases: one rich in Cs-Re-O, and the other rich in Na-Mo-O. The analyses performed showed that Cs and Re could be found in every particle sampled throughout the process, and that the micronic particles might originate from the aggregation of submicronic particles because of composition similarities. Thus, the observations led to a better understanding of the behavior of the elements of interest in both the melt and the gas phase.
Published: 2022

9. H2 gas production in calcium silicate hydrates: influence of water content and radiation induced defects

Author: Haas, Jeremy, Esnouf, Stéphane, Renault, Jean-Philippe, Dannoux-Papin, Adeline, Yin, Chengying, Laboratoire d’étude des Ciments et Bitumes pour le Conditionnement (LCBC), Département de recherche sur les technologies pour l'enrichissement, le démantèlement et les déchets (DE2D), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Laboratoire de Radiolyse et de la Matière Organique (LRMO), Service d'Etudes du Comportement des Radionucléides (SECR), Département de Physico-Chimie (DPC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Département de Physico-Chimie (DPC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Département de recherche sur les Procédés et Matériaux pour les Environnements complexes (DPME), Laboratoire Interdisciplinaire sur l'Organisation Nanométrique et Supramoléculaire (LIONS), Nanosciences et Innovation pour les Matériaux, la Biomédecine et l'Energie (ex SIS2M) (NIMBE UMR 3685), Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Rayonnement Matière de Saclay (IRAMIS), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)
Subjects: [CHIM.MATE]Chemical Sciences/Material chemistry, [CHIM.INOR]Chemical Sciences/Inorganic chemistry, [CHIM.RADIO]Chemical Sciences/Radiochemistry
Abstract: International audience; Water radiolysis is a major concern for the conditioning of radioactive waste in cement materials. Synthetic calcium silicate hydrate (CSH), the main hydrates of concrete, were synthesized with different C/S ratios and relative humidities. The samples were irradiated under γ- and electron beam irradiation. The radiolytic hydrogen production has been quantified and the radiation induced defect produced at low temperature characterized by electron paramagnetic resonance. The results show that the H production and defect production are only marginally sensitive to the relative humidity
Published: 2022

10. Leaching and Reactivity at the Sodium Aluminosilicate Glass–Water Interface: Insights from a ReaxFF Molecular Dynamics Study

Author: Hicham Jabraoui, Rodolphe Pollet, Stéphane Gin, Jean-Marc Delaye, Thibault Charpentier, Laboratoire Structure et Dynamique par Résonance Magnétique (LCF) (LSDRM), Nanosciences et Innovation pour les Matériaux, la Biomédecine et l'Energie (ex SIS2M) (NIMBE UMR 3685), Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Département de recherche sur les technologies pour l'enrichissement, le démantèlement et les déchets (DE2D), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Programmes Transversaux de Compétences Simulation Numérique (ALTERVER) of the French Alternative Energies and Atomic Energy Commission (CEA), HPC/AI resources of TGCC under the allocation 2021-A0100810825 made by GENCI, Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), and Département de recherche sur les Procédés et Matériaux pour les Environnements complexes (DPME)
Subjects: Materials science, Force field (physics), 02 engineering and technology, [CHIM.MATE]Chemical Sciences/Material chemistry, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, 0104 chemical sciences, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, Molecular dynamics, chemistry.chemical_compound, General Energy, Chemical engineering, chemistry, 13. Climate action, Reactivity (chemistry), Leaching (metallurgy), Physical and Theoretical Chemistry, ReaxFF, 0210 nano-technology, Sodium aluminosilicate
Abstract: International audience; In this study, we used ReaxFF reactive force field molecular dynamics (MD) simulations to investigate the dynamics associated with reactivity at the sodium aluminosilicate (NAS) glass–water interface. By combining van Hove correlation functions and visual analysis of individual trajectories, we found that when a Na+ ion leaves its initial position at the glass surface under the effect of water, it can be replaced either by a H+ ion or by another diffused Na+, resulting in a (Na+ ⇌ H+) ion exchange or (Na+ ⇌ Na+) ion exchange, respectively. These rearrangements at the NAS glass–water interface take place through many events such as the formation of oxygen-bearing functional groups (silanol Si(OH), germinal silanol Si(OH)2, and Al(OH)) and the agglomeration of Na+ ions on the glass surface. The high affinity between water and Na+ ions leads to two events, namely, the penetration of the water molecule into the first glass layer and the release of Na+ ions into the bulk water. The release of sodium ions into bulk water takes place via several successive steps: (1) leaving their original position to an area more exposed to bulk water, (2) diffusion to the surface of the glass, (3) leaving the surface toward the solution, and (4) coming back to the glass surface. Statistical analysis shows that oxygen-bearing functional group formation occurs both by protonation of the nonbridging oxygen (NBO) site and by filling defects such as SiIII, AlIII, and AlIV by OH– resulting from the dissociation of water molecules, while in the bulk, they could be produced by the proton jumps between two adjacent NBO sites and dissociation of the water diffused in deep layers of glass. Germinal silanol groups (Si(OH)2) are present in small amounts in the first layer of the glass after the protonation of two NBOs from a single SiIV. This process is accompanied by the conversion of AlIII and AlIV units into AlV units and SiIII units into SiIV units. By comparing the networks of Si and Al, we found that Al is more impacted by the occurrence of water molecules than Si, which is explained by an increase in the diffusion coefficient of Al compared with Si when these units become protonated (Si(OH) and Al(OH)).
Published: 2021

11. H2 production under gamma irradiation of a calcium aluminate cement: An experimental study on both cement pastes and its stable hydrates

Author: David Chartier, F. Dunstetter, Adeline Dannoux-Papin, Olivier Cavani, Mireille Courtial, Loren Acher, Sandrine Tusseau-Nenez, Marie-Noëlle de Noirfontaine, Dominique Gorse – Pomonti, Jérémy Haas, CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Laboratoire des Solides Irradiés (LSI), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X), Laboratoire d’étude des Ciments et Bitumes pour le Conditionnement (LCBC), Département de recherche sur les technologies pour l'enrichissement, le démantèlement et les déchets (DE2D), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Laboratoire de physique de la matière condensée (LPMC), École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Université d'Artois (UA), and Département de recherche sur les Procédés et Matériaux pour les Environnements complexes (DPME)
Subjects: musculoskeletal diseases, Materials science, Aluminate, Context (language use), 02 engineering and technology, calcium aluminate cement, law.invention, chemistry.chemical_compound, law, Radiolysis, C3AH6 hydrogarnet katoite, Calcium aluminate cements, Gibbsite, ComputingMilieux_MISCELLANEOUS, Cement, Magnesium phosphate, Radiation, 020502 materials, technology, industry, and agriculture, AH3 gibbsite, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, equipment and supplies, gamma irradiation, Portland cement, surgical procedures, operative, 0205 materials engineering, chemistry, Chemical engineering, hydrogen, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], 0210 nano-technology, Hydrate, [CHIM.RADIO]Chemical Sciences/Radiochemistry
Abstract: International audience; The objective of this paper is to investigate the use of calcium aluminate cements as alternative cements within the context of nuclear waste stabilization by solidification. Using an external 60 Co source, the effect of γ-radiation on H2 gas production of one of the calcium aluminate cement-based materials (cement "Ciment Fondu") and its stable hydrates, was studied. The amount of H2 produced by these cement pastes is found to be much lower (up to five times less) than that of the Portland cement pastes containing the same amount of water, especially in the low range of water to cement ratios (W/C ≤ 0.4) where water is essentially engaged in the hydrates. The H2 production of the two major hydrates of Ciment Fondu, gibbsite AH3 and katoite hydrogarnet C3AH6, is very low compared with that of the main hydrates of other cements (Portland cement, Calcium Sulfo-Aluminate and Magnesium Phosphate cements). The type of water engaged in the hydrates, as hydroxyl groups and/or molecular water, influences significantly the H2 production. Thus, the nature of the hydrate is a key parameter to the aim of optimizing cement matrices with respect to the gas production under irradiation. XRD analysis shows that the crystal structures of gibbsite and katoite are preserved up to very high doses under electron irradiation (3 GGy). This makes calcium aluminate cements (CAC) potential good candidates for nuclear waste conditioning from the point of view of their stability under irradiation.
Published: 2021

12. Study of the conditioning of aluminum-magnesium alloys in magnesium potassium phosphate cement

Author: PORAS, Gabriel, CAU DIT COUMES, Celine, Antonucci, Pascal, Cannes, Céline, Delpech, Sylvie, Perrin, Stephane, Laboratoire d’étude des Ciments et Bitumes pour le Conditionnement (LCBC), Département de recherche sur les Procédés et Matériaux pour les Environnements complexes (DPME), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Laboratoire de Physique des 2 Infinis Irène Joliot-Curie (IJCLab), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), and Département de recherche sur les technologies pour l'enrichissement, le démantèlement et les déchets (DE2D)
Subjects: [CHIM.MATE]Chemical Sciences/Material chemistry, ComputingMilieux_MISCELLANEOUS
Abstract: International audience
Published: 2021

13. Flame resistance of geopolymer foam coatings for the fire protection of steel

Author: Catherine A. Davy, Gaelle Fontaine, Grégory Tricot, Johan Sarazin, Jerome Hosdez, David Lambertin, Serge Bourbigot, Unité Matériaux et Transformations - UMR 8207 (UMET), Centrale Lille-Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Unité de Catalyse et Chimie du Solide - UMR 8181 (UCCS), Université d'Artois (UA)-Centrale Lille-Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Institut Universitaire de France (IUF), Ministère de l'Education nationale, de l’Enseignement supérieur et de la Recherche (M.E.N.E.S.R.), Laboratoire Avancé de Spectroscopie pour les Intéractions la Réactivité et l'Environnement - UMR 8516 (LASIRE), Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Mécanique Multiphysique Multiéchelle (LaMcube), Centrale Lille-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Laboratoire d’étude des Ciments et Bitumes pour le Conditionnement (LCBC), Département de recherche sur les Procédés et Matériaux pour les Environnements complexes (DPME), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), European Project: 670747,H2020,ERC-2014-ADG,FireBar-Concept(2016), Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centrale Lille Institut (CLIL), Centrale Lille Institut (CLIL)-Université d'Artois (UA)-Centrale Lille-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Lille, Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Centrale Lille Institut (CLIL), Université de Lille-Centrale Lille-Centre National de la Recherche Scientifique (CNRS), Département de recherche sur les technologies pour l'enrichissement, le démantèlement et les déchets (DE2D), Université de Lille, CNRS, INRA, ENSCL, Unité Matériaux et Transformations (UMET) - UMR 8207, Unité de Catalyse et Chimie du Solide - UMR 8181 [UCCS], Institut Universitaire de France [IUF], Laboratoire Avancé de Spectroscopie pour les Intéractions la Réactivité et l'Environnement (LASIRE) - UMR 8516, Unité Matériaux et Transformations - UMR 8207 [UMET], Unité de Mécanique de Lille (UML) - ULR 7512, Laboratoire Avancé de Spectroscopie pour les Intéractions la Réactivité et l'Environnement - UMR 8516 [LASIRE], Laboratoire de Mécanique Multiphysique Multiéchelle [LaMcube], and Laboratoire d’étude des Ciments et Bitumes pour le Conditionnement [LCBC]
Subjects: Fire test, Temperature, Stability, Alkali activated cement, Silica fume, Refractory cement, Materials science, 02 engineering and technology, engineering.material, 010402 general chemistry, 01 natural sciences, Industrial and Manufacturing Engineering, Coating, Composite material, Porosity, Metakaolin, Curing (chemistry), Cement, Mechanical Engineering, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, 0104 chemical sciences, Geopolymer, [CHIM.POLY]Chemical Sciences/Polymers, Mechanics of Materials, Ceramics and Composites, engineering, 0210 nano-technology
Abstract: International audience; This research investigates the fire resistance of novel geopolymer (GP) foams, based on alkali-activated metakaolin and silica fume (SF). Fresh GP foams are applied as coatings on steel plates. After one week curing, the foams are subjected to a flame burn-through test. Changes in their physico-chemical properties are characterized before and after fire test, mainly with XRD, quantitative MAS NMR, electron probe micro-analysis, quantitative X ray micro-computed tomography and heat conductivity. Results show that GP foams are excellent thermal barriers, providing up to 251 °C less than for uncoated steel plate. Their porosity ranges between 25 and 81%, for typical pore sizes d50 from 0.5 to 3.0 mm 29Si MAS NMR shows that the proportion of GP cement only decreases from 60-68% to 53–58% after fire. SF expands and creates small pores in the coating, which is favorable to decrease heat conductivity by a factor of 2 whatever the foam.
Published: 2021

14. Investigation of alumino-silicate glasses by coupling experiments and simulations: Part I - Structures

Author: S. Peuget, J.M. Delaye, F. Lodesani, A. Le Gac, S. Macaluso, Frédéric Angeli, Thibault Charpentier, Département de recherche sur les technologies pour l'enrichissement, le démantèlement et les déchets (DE2D), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Laboratoire Structure et Dynamique par Résonance Magnétique (LCF) (LSDRM), Nanosciences et Innovation pour les Matériaux, la Biomédecine et l'Energie (ex SIS2M) (NIMBE UMR 3685), Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Département de recherche sur les Procédés et Matériaux pour les Environnements complexes (DPME), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Rayonnement Matière de Saclay (IRAMIS), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Materials science, Alumino-silicate glasses, 02 engineering and technology, Molecular dynamics, 01 natural sciences, symbols.namesake, NMR, Raman, structure, Aluminosilicate, Raman band, 0103 physical sciences, Materials Chemistry, Coupling (piping), 010302 applied physics, Nuclear magnetic resonance spectroscopy, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 3. Good health, Electronic, Optical and Magnetic Materials, Chemical physics, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], Ceramics and Composites, symbols, Gradual increase, 0210 nano-technology, Raman spectroscopy
Abstract: International audience; A set of alumino-silicate glasses with SiO2-Al2O3-Na2O-CaO compositions was investigated using Raman and NMR spectroscopy techniques and by classical molecular dynamics, in order to study the structural modifications which occur when CaO progressively replaces Na2O and when Al2O3 progressively replaces SiO2. The effect of a gradual increase in the Al2O3 content was also studied. Al was always 4 coordinated for all the compositions studied, including the peraluminous glasses. An increase in the number of Al-O-Al bonds was found when the Al2O3 or CaO content increases. The study confirmed that AlO4 groupings are preferentially compensated by Na rather than by Ca, and that there are non-bridging oxygens surrounded by mixed environments containing both Na and Ca. Combining the information given by the Raman and NMR spectroscopy results enabled the attribution of the Raman band at 570cm-1 to the Si-O-Si bonds. It confirmed that the band at 510cm-1 can be attributed to the Si-O-Al bonds, while that at 985cm-1 can be attributed to the Q4-Al entities. Lastly, it was demonstrated that the classical molecular dynamics potentials of Deng et al., specifically developed for this type of glasses, permit the reproduction of a large number of the experimental results quantitatively or sometimes simply qualitatively.
Published: 2021

15. Irradiation externe aux ions lourds de céramiques et vitrocéramiques d'apatite silicatée au néodyme

Author: J.-L. Dussossoy, Daniel Caurant, Pascal Loiseau, Clara Grygiel, S. Peuget, Nolwenn Chouard, Odile Majérus, Groupe d'Etudes des Matériaux Hétérogènes (GEMH), Université de Limoges (UNILIM)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM), Laboratoire de Chimie Appliquée de l'État Solide (LCAES), Ecole Nationale Supérieure de Chimie de Paris - Chimie ParisTech-PSL (ENSCP), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Institut de minéralogie et de physique des milieux condensés (IMPMC), Université Pierre et Marie Curie - Paris 6 (UPMC)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Laboratoire des Matériaux et Procédés Actifs (LMPA), Département de recherche sur les technologies pour l'enrichissement, le démantèlement et les déchets (DE2D), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Centre de recherche sur les Ions, les MAtériaux et la Photonique (CIMAP - UMR 6252), Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Caen Normandie (UNICAEN), Normandie Université (NU), Service d'Etudes du Comportement des Matériaux de Conditionnement (SECM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Diderot - Paris 7 (UPD7)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS), Département de recherche sur les Procédés et Matériaux pour les Environnements complexes (DPME), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche de Chimie Paris (IRCP), Ecole Nationale Supérieure de Chimie de Paris- Chimie ParisTech-PSL (ENSCP)-Centre National de la Recherche Scientifique (CNRS)-Ministère de la Culture (MC), and Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Nuclear and High Energy Physics, Materials science, Ion beam, Analytical chemistry, 02 engineering and technology, 01 natural sciences, Apatite, 010305 fluids & plasmas, law.invention, Ion, chemistry.chemical_compound, symbols.namesake, Swift heavy ion, law, 0103 physical sciences, [CHIM]Chemical Sciences, General Materials Science, Irradiation, ComputingMilieux_MISCELLANEOUS, Glass-ceramic, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Silicate, Nuclear Energy and Engineering, chemistry, visual_art, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], visual_art.visual_art_medium, symbols, 0210 nano-technology, Raman spectroscopy
Abstract: This work aims at comparing the damage induced in the Nd silicate apatite ceramic (Ca2Nd8(SiO4)6O2) by medium energy (ME) and swift heavy ion (SHI) irradiations to evaluate the effects of nuclear collisions and intense electronic excitations for ME ions and SHI ions respectively. The macroscopic induced changes were studied as a function of the fluence by swelling and hardness measurements, whereas structural modifications were followed by X-ray diffraction, Raman spectroscopy and grazing incidence EXAFS (Nd L3-edge). At ME (1.9–6.75 MeV Au ions), radiation-induced amorphization occurred above 6.22 × 1013 Au/cm2 associated with a volume expansion of about 8% and a drop of 37% in hardness. At SHI (90 MeV Xe ions or 35 MeV Ar ions), similar macroscopic and structural changes were observed. The electronic stopping power threshold of Nd silicate apatite for amorphization was assessed at about Se = 5 keV/nm. As apatite crystals containing actinides could be present in rare-earths rich nuclear glasses, SHI irradiation with Xe (995 MeV) ions was also used to damage the Nd silicate apatite crystals dispersed in a soda-lime aluminoborosilicate simplified nuclear glass over a depth of about 60 μm, to evaluate the possible formation of cracks in the residual glass due to crystals swelling. In spite of apatite crystals amorphization under SHI irradiation in the glass-ceramics, no cracking was observed in the glassy phase even close to the biggest crystals which could be explained by strain relaxation in the glass due to plastic deformation (creep) induced by SHI ion beam.
Published: 2019

16. Molecular dynamics simulation of ballistic effects in simplified nuclear waste glasses

Author: Jean-Marc Delaye, Amreen Jan, Stéphane Gin, Sebastien N. Kerisit, Pacific Northwest National Laboratory (PNNL), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Laboratoire des Matériaux et Procédés Actifs (LMPA), Département de recherche sur les technologies pour l'enrichissement, le démantèlement et les déchets (DE2D), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), and Département de recherche sur les Procédés et Matériaux pour les Environnements complexes (DPME)
Subjects: Materials science, Sodium, Analytical chemistry, chemistry.chemical_element, 02 engineering and technology, Molecular dynamics, ballistic effects, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Condensed Matter::Disordered Systems and Neural Networks, 01 natural sciences, 0103 physical sciences, Materials Chemistry, Radiation damage, Irradiation, borosilicate glasses, 010302 applied physics, Range (particle radiation), Internal energy, Borosilicate glass, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Electronic, Optical and Magnetic Materials, Elastic collision, Condensed Matter::Soft Condensed Matter, chemistry, Ceramics and Composites, 0210 nano-technology
Abstract: Ballistic effects in simple sodium borosilicate ( Na 2 O B 2 O 3 = 1 ) and sodium alumino-borosilicate glasses ( Na 2 O − Al 2 O 3 B 2 O 3 = 1 ) were investigated using molecular dynamics simulations. Specifically, the glasses were irradiated with heavy projectiles that caused atomic displacements by elastic collisions (displacement cascades) and progressively damaged the bulk glass. The accumulated pressure and internal energy inside the glass were found to saturate with deposited energy. Furthermore, structural analysis of the irradiated glasses revealed several important ballistic effects including a decrease in glass density, depolymerization of the borosilicate network, and increase in chemical mixing, short range and intermediate disorder. The magnitude of radiation damage was found to depend on the glass composition and, in general, alumino-borosilicate glasses were found to be slightly less damaged, after irradiation, as compared to borosilicate glasses.
Published: 2019

17. The fate of Si and Fe while nuclear glass alters with steel and clay

Author: Mandana Saheb, Stéphane Gin, Philippe Dillmann, L. Gentaz, James J. Dynes, Nicolas Nuns, Nicolas Michau, A. Delanoë, Emmanuel Gardés, Christelle Martin, Eddy Foy, F. Bruguier, Delphine Neff, Charly Carrière, Isabelle Monnet, Laboratoire Archéomatériaux et Prévision de l'Altération (LAPA - UMR 3685), Nanosciences et Innovation pour les Matériaux, la Biomédecine et l'Energie (ex SIS2M) (NIMBE UMR 3685), Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Institut de Recherches sur les Archéomatériaux (IRAMAT), Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Université Bordeaux Montaigne-Université de Technologie de Belfort-Montbeliard (UTBM), Département de recherche sur les technologies pour l'enrichissement, le démantèlement et les déchets (DE2D), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Centre de recherche sur les Ions, les MAtériaux et la Photonique (CIMAP - UMR 6252), Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Caen Normandie (UNICAEN), Normandie Université (NU), Laboratoire Interuniversitaire des Systèmes Atmosphériques (LISA (UMR_7583)), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Institut des Molécules et de la Matière Condensée de Lille (IMMCL), Centrale Lille Institut (CLIL)-Centre National de la Recherche Scientifique (CNRS)-Université de Lille, Sciences et Technologies, Canadian Light Source, University of Saskatchewan [Saskatoon] (U of S), Agence Nationale pour la Gestion des Déchets Radioactifs (ANDRA), CNRS, CEA, ANDRA, ANR-11-EQPX-0020,GENESIS,Groupe d'Etudes et de Nanoanalyses des Effets d'IrradiationS(2011), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Université de Technologie de Belfort-Montbeliard (UTBM)-Université d'Orléans (UO)-Université Bordeaux Montaigne (UBM)-Centre National de la Recherche Scientifique (CNRS), Département de recherche sur les Procédés et Matériaux pour les Environnements complexes (DPME), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Université de Lille, Sciences et Technologies-Centrale Lille-Centre National de la Recherche Scientifique (CNRS), Université de Technologie de Belfort-Montbeliard (UTBM)-Université d'Orléans (UO)-Université Bordeaux Montaigne-Centre National de la Recherche Scientifique (CNRS), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), and Université de Lille, Sciences et Technologies-Centre National de la Recherche Scientifique (CNRS)-Centrale Lille Institut (CLIL)
Subjects: Mineral, Materials science, Materials Science (miscellaneous), Analytical chemistry, Radioactive waste, Nontronite, 02 engineering and technology, [CHIM.MATE]Chemical Sciences/Material chemistry, 010502 geochemistry & geophysics, 021001 nanoscience & nanotechnology, 01 natural sciences, Glass dissolution, Chemistry (miscellaneous), TA401-492, Materials Chemistry, Ceramics and Composites, 0210 nano-technology, Clay minerals, Materials of engineering and construction. Mechanics of materials, Layer (electronics), Dissolution, 0105 earth and related environmental sciences
Abstract: The French concept developed to dispose high-level radioactive waste in geological repository relies on glassy waste forms, isolated from the claystone host rock by steel containers. Understanding interactions between glass and surrounding materials is key for assessing the performance of a such system. Here, isotopically tagged SON68 glass, steel and claystone were studied through an integrated mockup conducted at 50 °C for 2.5 years. Post-mortem analyses were performed from nanometric to millimetric scales using TEM, STXM, ToF-SIMS and SEM techniques. The glass alteration layer consisted of a crystallized Fe-rich smectite mineral, close to nontronite, supporting a dissolution/reprecipitation controlling mechanism for glass alteration. The mean glass dissolution rate ranged between 1.6 × 10−2 g m−2 d−1to 3.0 × 10−2g m−2 d−1, a value only 3–5 times lower than the initial dissolution rate. Thermodynamic calculations highlighted a competition between nontronite and protective gel, explaining why in the present conditions the formation of a protective layer is prevented.
Published: 2021

18. Amorphization of a Proposed Sorbent of Strontium, Brushite, CaHPO4•2H2O, Studied by X-ray Diffraction and Raman Spectroscopy

Author: Jihane Jdaini, M. Courtial, Dominique Gorse-Pomonti, Céline Cau-Dit-Coumes, Enrique Garcia-Caurel, F. Dunstetter, Olivier Cavani, Sandrine Tusseau-Nenez, Daniel Funes-Hernando, Marie-Noëlle de Noirfontaine, Laboratoire des Solides Irradiés (LSI), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X), Laboratoire de physique des interfaces et des couches minces [Palaiseau] (LPICM), École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Université d'Artois (UA), Laboratoire de physique de la matière condensée (LPMC), Département de recherche sur les technologies pour l'enrichissement, le démantèlement et les déchets (DE2D), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), and Département de recherche sur les Procédés et Matériaux pour les Environnements complexes (DPME)
Subjects: Nuclear and High Energy Physics, Materials science, Analytical chemistry, 02 engineering and technology, engineering.material, 01 natural sciences, Portlandite, 010305 fluids & plasmas, symbols.namesake, 0103 physical sciences, Radiation damage, General Materials Science, Brushite, Irradiation, Brucite, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Amorphous solid, X-ray diffraction, CaHPO4•2H2O, Nuclear Energy and Engineering, calcium pyrophosphates, radiation damage, X-ray crystallography, Raman spectroscopy, symbols, engineering, 0210 nano-technology
Abstract: International audience; We present a systematic study of the transformation of brushite (dicalcium phosphate dihydrate, CaHPO4•2H2O) under irradiation of electrons of well-defined energy (2.5 MeV) and flux as a function of the irradiation dose. Contrarily to model hydroxides such as portlandite and brucite, which are very resistant to electron radiation damage, the studied brushite decomposes quite easily, even for very low irradiation doses. Irradiated brushite samples were characterized using X-ray diffraction (XRD) and Raman spectroscopy to get complementary information about changes in atomic structure and chemical composition respectively under irradiation. XRD showed that irradiation causes a very limited dilatation of unit cell of crystalline brushite, which becomes progressively amorphous with increasing radiation dose. Raman spectroscopy complemented XRD results and confirmed that the transformation of brushite to the amorphous phase was not abrupt, but rather progressive. Raman spectroscopy allowed for the identification of the amorphous phase as a calcium pyrophosphate. Both techniques showed that the amorphization of brushite was not fully complete at the maximum dose used, 5.5 GGy (4 C). Interestingly, monetite phase, (CaHPO4 dicalcium phosphate), was not detected at any step of the transformation as it is the case when brushite is thermally decomposed. This study reveals the high sensitivity to electron radiation of both hydrogen bonds and protonated phosphate units in brushite, thus facilitating the transformation into pyrophosphate. The damage of brushite by energetic electrons is to be carefully considered for applications related to the use of brushite as ion-exchanger in the decontamination of effluents polluted with strontium-90, an efficient beta ray emitter.
Published: 2021

19. Dismantling nuclear waste rich in P2O5, MoO3 and ZrO2: How do these oxides incorporate in aluminoborosilicate glasses?

Author: Daniel Caurant, Elise Régnier, Odile Majérus, Sophie Achigar, Institut de Recherche de Chimie Paris (IRCP), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Ecole Nationale Supérieure de Chimie de Paris - Chimie ParisTech-PSL (ENSCP), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Ministère de la Culture (MC), Commissariat à l'Energie Atomique, Centre de Marcoule (CEA), Département de recherche sur les Procédés et Matériaux pour les Environnements complexes (DPME), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Ecole Nationale Supérieure de Chimie de Paris - Chimie ParisTech-PSL (ENSCP), Université Paris sciences et lettres (PSL), Andra via un Programme investissement d'avenir (PIA), DEM&MELT project, Département de recherche sur les technologies pour l'enrichissement, le démantèlement et les déchets (DE2D), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Ministère de la Culture (MC)
Subjects: Nuclear and High Energy Physics, Materials science, P2O5, chemistry.chemical_element, waste vitrification, 02 engineering and technology, [CHIM.INOR]Chemical Sciences/Inorganic chemistry, 01 natural sciences, 010305 fluids & plasmas, law.invention, law, Phase (matter), cesium, 0103 physical sciences, [CHIM]Chemical Sciences, General Materials Science, Crystallization, Solubility, Zirconium, Radioactive waste, Nuclear dismantling, 021001 nanoscience & nanotechnology, Microstructure, Spent nuclear fuel, Nuclear Energy and Engineering, chemistry, Chemical engineering, 13. Climate action, Molybdenum, and ZrO2 incorporation, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], MoO3, 0210 nano-technology, aluminoborosilicate glass
Abstract: International audience; Dismantling nuclear facilities leads to radioactive waste less active but which may have highly variable compositions compared to the high-level radioactive wastes recovered after the reprocessing of spent nuclear fuel. In this work, we studied the ability of an alkali-rich glass matrix belonging to the SiO2-B2O3-Al2O3-Fe2O3-Na2O-Li2O-CaO system to solubilize P2O5, MoO3, ZrO2 and Cs2O by melting at 1100°C. Phosphorus, molybdenum, zirconium and cesium are present as a mixture of complex compounds in the real radioactive dismantling waste containing 137Cs considered here. To determine the capacity of the matrix to accept a wide range of variations of waste composition and the solubility limits of P2O5, MoO3, and ZrO2, several glass series were prepared by melting mixtures of raw materials (oxides, carbonates, phosphates) and by increasing the total amount of oxides representing the waste and varying their relative proportions. Their incorporation in the melt was studied by analyzing the microstructure of quenched glasses by XRD and SEM-EDS. In addition, the phase separation and crystallization tendencies during cooling were studied by analyzing the microstructure of glasses cooled at 1°C.min-1 from 1100°C (representative of cooling in industrials steel canisters). It is shown that the glass can accept a wide range of waste compositions without exhibiting heterogeneities. For all compositions the melt remained homogeneous (study of quenched samples). However, during slow cooling, P2O5 and MoO3 may lead to phase separation and crystallization of Na2MoO4, CsLiMoO4, NaCaPO4, NaLi2PO4, and Li3PO4. Cs can be partially incorporated into the molybdenum-rich phase CsLiMoO4 when MoO3 content is higher than 1.3wt%. ZrO2 never lead to phase separation or crystallization, possibly because of the existence of strong connections between Zr and Si through Zr-O-Si bonds whereas P and Mo would be present as PO43− and MoO42− mobile entities. The increasing order of oxides solubility in the glass is the following: MoO3
Published: 2021

20. Characterization of the boron profile and coordination in altered glass layers by EEL spectroscopy

Author: H.P. Brau, Diane Rébiscoul, Martiane Cabié, Nicole Godon, Héléne Arena, Jaysen Nelayah, E. Garcés, Renaud Podor, C. Mansas, Département de recherche sur les technologies pour l'enrichissement, le démantèlement et les déchets (DE2D), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Etude de la Matière en Mode Environnemental (L2ME), Institut de Chimie Séparative de Marcoule (ICSM - UMR 5257), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Laboratoire Matériaux et Phénomènes Quantiques (MPQ (UMR_7162)), Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Catalyse, Polymérisation, Procédés et Matériaux (CP2M), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-École supérieure de Chimie Physique Electronique de Lyon (CPE)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Nanomatériaux pour l'Energie et le Recyclage (LNER), Département de recherche sur les Procédés et Matériaux pour les Environnements complexes (DPME), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), and Université de Lyon-Université de Lyon-École Supérieure de Chimie Physique Électronique de Lyon (CPE)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Materials science, General Physics and Astronomy, chemistry.chemical_element, Spectroscopy, Electron Energy-Loss, 02 engineering and technology, Electron, 01 natural sciences, Structural Biology, Materials Testing, 0103 physical sciences, [CHIM]Chemical Sciences, General Materials Science, Sample preparation, Spectroscopy, Boron, ComputingMilieux_MISCELLANEOUS, 010302 applied physics, Minerals, Cell Biology, 021001 nanoscience & nanotechnology, Characterization (materials science), chemistry, Chemical engineering, Bonding strength, Nanometre, Glass, 0210 nano-technology, Layer (electronics)
Abstract: Electron energy-loss spectroscopy was used to characterize the boron profile and its coordination (BIII and BIV), along the complex alteration layer of glass samples altered for 511 days at 50 °C in solution containing FeCl2, MgCl2 and/or CaCl2. To reach this goal, the impact of both TEM operating conditions and sample preparation on the determination of the boron coordination was first studied using mineralogical and pristine glasses reference samples. Then, the boron concentration profiles were characterized in the glass alteration layer. These profiles were found to be S-shaped with a thickness around forty nanometers. The proportion of BIII was found to decrease with the boron total concentration (from the pristine glass to the gel layer), which suggests a higher bonding strength for BIV bonds than that of BIII bonds under the alteration conditions. These findings are of tremendous interest to advance further in the understanding of glass alteration mechanisms.
Published: 2021

21. Ten years after the NPP accident at Fukushima : review on fuel debris behavior in contact with water

Author: Ayako Nitta, Ryu Takami, Yoshikazu Koma, Toshihiko Ohnuki, Hugo Laffolley, Satoshi Utsunomiya, Christophe Jegou, Kazuki Fueda, Bernd Grambow, Christophe Journeau, Atsuhiro Shibata, Laboratoire de physique subatomique et des technologies associées (SUBATECH), Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), Laboratoire d'Etudes du Comportement à Long Terme des matériaux de conditionnement (LCLT), Département de recherche sur les technologies pour l'enrichissement, le démantèlement et les déchets (DE2D), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), CEA Cadarache, Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Université de Nantes (UN)-Université de Nantes (UN)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique (IMT Atlantique), and Département de recherche sur les Procédés et Matériaux pour les Environnements complexes (DPME)
Subjects: [PHYS]Physics [physics], Nuclear and High Energy Physics, Waste management, 020209 energy, FUKUSHIMA, 02 engineering and technology, 010501 environmental sciences, Corium, 7. Clean energy, 01 natural sciences, Debris, Spent nuclear fuel, leaching, fuel debris, Nuclear Energy and Engineering, 13. Climate action, 0202 electrical engineering, electronic engineering, information engineering, Environmental science, Leaching (metallurgy), spent nuclear fuel, 0105 earth and related environmental sciences
Abstract: International audience; Following the NPP accident, several hundred tons of heat-generating corium and fuel debris have been cooled permanently by millions of m3 of flowing. Knowledge on the interaction with water is crucial for any decommissioning planning.Starting from knowledge on the evolutions of the accident in the three reactor cores and associated fuel debris formations and some additional isotopic and physio-chemical information on debris fragments collected in Fukushima soils, we review the temporal evolution of the chemistry and leached radionuclide contents of the cooling water, comparing measured concentration ratios of the actinides and fission products in the water to reported results of laboratory leaching studies with either spent nuclear fuel or simulated fuel debris.As for spent fuel leaching, the fractions of inventories of 134,137Cs in the cooling water are orders of magnitude larger than that of the actinides. After more than 10 years of fuel debris/water contact, 137Cs release rates have decreased by about a factor of 100. The total release of actinides from the fuel debris is orders of magnitude lower than that of 134,137Cs or of 90Sr. This high stability makes direct disposal of fuel debris in suitable containers after decommissioning a viable option.
Published: 2021

22. Aqueous alteration of silicate glass: State of knowledge and perspectives

Author: Stéphane Gin, J.M. Delaye, Sophie Schuller, Frédéric Angeli, Laboratoire d'Etudes du Comportement à Long Terme des matériaux de conditionnement (LCLT), Département de recherche sur les Procédés et Matériaux pour les Environnements complexes (DPME), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), This work was funded by CEA (VESTALE project), and Département de recherche sur les technologies pour l'enrichissement, le démantèlement et les déchets (DE2D)
Subjects: Materials science, Thermodynamic equilibrium, Materials Science (miscellaneous), 02 engineering and technology, Experimental validation, [CHIM.MATE]Chemical Sciences/Material chemistry, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, Durability, 0104 chemical sciences, 13. Climate action, Chemistry (miscellaneous), TA401-492, Materials Chemistry, Ceramics and Composites, Biochemical engineering, 0210 nano-technology, Materials of engineering and construction. Mechanics of materials, Silicate glass
Abstract: The question of silicate glass chemical durability is at the heart of many industrial and environmental issues, with certain glasses, such as bioglasses, needing to transform rapidly, while others, like nuclear glasses, extremely slowly. Due to the wide diversity of the chemical composition for these types of materials and their metastability—no thermodynamic equilibrium can be reached between glass and solution—the evaluation of chemical durability remains a scientific challenge. In this article, we review the current state of knowledge on glass alteration mechanisms and kinetics, and point to some perspectives for glasses for which no direct experimental validation is currently possible. Thanks to the development of novel techniques and international collaborations, a better understanding of the mechanisms involved has been achieved. Mechanistic models have been developed at some specific scales, although holistic models still need further development to link the various scales and perform reliable predictions.
Published: 2021

23. Influence of temperature and relative humidity on vapor hydration of an AVM nuclear waste glass

Author: Loryelle Sessegolo, Patrick Jollivet, Abdesselam Abdelouas, Frédéric Angeli, Sathya Narayanasamy, Laboratoire d'Etudes du Comportement à Long Terme des matériaux de conditionnement (LCLT), Département de recherche sur les technologies pour l'enrichissement, le démantèlement et les déchets (DE2D), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Laboratoire Interuniversitaire des Systèmes Atmosphériques (LISA (UMR_7583)), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Laboratoire de physique subatomique et des technologies associées (SUBATECH), Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), Université de Nantes (UN)-Université de Nantes (UN)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), and Département de recherche sur les Procédés et Matériaux pour les Environnements complexes (DPME)
Subjects: Nuclear and High Energy Physics, Materials science, Morphology (linguistics), Analytical chemistry, Context (language use), 02 engineering and technology, Activation energy, 01 natural sciences, 010305 fluids & plasmas, symbols.namesake, Transition metal, 0103 physical sciences, Gel layer, Secondary phases, Mechanisms, General Materials Science, Relative humidity, Vapor hydration, Arrhenius equation, [PHYS]Physics [physics], Glasses, Radioactive waste, food and beverages, Atmospheric temperature range, 021001 nanoscience & nanotechnology, humanities, Nuclear Energy and Engineering, 13. Climate action, symbols, 0210 nano-technology
Abstract: The safety assessment of the geological disposal of nuclear waste glasses requires a thorough understanding of the vapor hydration mechanisms of these glasses. In this context, the effect of temperature and relative humidity on vapor hydration of the AVM6 glass, which is the most reactive among the studied French AVM glasses, was investigated in the present study. Polished glass monoliths were vapor hydrated for 1 year (i) at 97% relative humidity (RH), at temperatures 70°C and 90°C to study the effect of temperature and (ii) at 50°C and 50% RH, 76% RH, 88% RH and 97% RH to study the effect of RH. The altered glass samples were characterized by SEM, XRD and ToF-SIMS. The results were compared with published results of AVM6 glass vapor hydrated at 50°C and 95% RH. The nature of the secondary phases that precipitate varied with both temperature and relative humidity, leading to variation in the behavior of elements in the altered layer (gel) but the altered layer morphology is similar at all temperatures studied. The Arrhenius law for temperature dependence is respected between the temperature range 50–90°C and the activation energy suggests that network-hydrolysis is the predominant rate controlling mechanism at these temperatures and duration. The secondary phases that incorporate transition metals and rare-earth elements are identified by XRD only in experiments conducted at lower RH values.
Published: 2021

24. Structural and rheological analysis of nickel enriched peraluminous glasses

Author: HANSEN, Erik, Perret, Damien, GIBOIRE, Isabelle, Mure, Sylvain, Rapin, Christophe, Département de recherche sur les technologies pour l'enrichissement, le démantèlement et les déchets (DE2D), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Institut Jean Lamour (IJL), Université de Lorraine (UL)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Département de recherche sur les Procédés et Matériaux pour les Environnements complexes (DPME), and Institut de Chimie du CNRS (INC)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Chemistry, crystallization, Peraluminous glass, viscosity, TA401-492, nickel oxide, [CHIM.MATE]Chemical Sciences/Material chemistry, [CHIM.INOR]Chemical Sciences/Inorganic chemistry, Materials of engineering and construction. Mechanics of materials, QD1-999, incorporation limit
Abstract: International audience; This study describes the role of nickel oxide (NiO) in peraluminous glass. Peraluminous glass is defined by an excess of aluminium ions (Al3+) compared to modifier elements such as Na+, Li+ or Ca2+ ions. The study investigates the effect NiO incorporation on peraluminous glass homogeneity and process ability. Quenched NiO-containing glass showed an incorporation limit greater than 12 wt% NiO (13.8 mol%), while slowly cooled glass showed a limit of 5 wt% NiO (5.8 mol%). Nickel oxide is also found to have a fludifying effect on peraluminous glasses. When the nickel oxide content is above its incorporation limit, the resulting crystals were found to have a significant effect on glass rheological properties. Finally, hypotheses are proposed as to the structural role of Ni in peraluminous glass based on the experimental results obtained.
Published: 2021

25. Assessment of a bolted-flange connection for ITER Test Blanket Module

Author: Karl Vulliez, Stephane Gazzotti, Jean-Pierre Friconneau, J.P. Martins, Benjamin Michel, Tony Zaouter, Département de recherche sur les Procédés et Matériaux pour les Environnements complexes (DPME), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Institut de Recherche sur la Fusion par confinement Magnétique (IRFM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), ITER organization (ITER), funding of the ‘SSA-51’ working agreement between the CEA and ITER Organization, joint maestral sealing laboratory (CEA – Technetics Group France), and Département de recherche sur les technologies pour l'enrichissement, le démantèlement et les déchets (DE2D)
Subjects: Computer science, Connection (vector bundle), Pipe Forest, Mechanical engineering, Test Blanket Module, Port (circuit theory), Welding, Numerical simulation, Blanket, Flange, 01 natural sciences, 010305 fluids & plasmas, law.invention, [SPI]Engineering Sciences [physics], law, ITER, 0103 physical sciences, Water cooling, General Materials Science, 010306 general physics, Dimensioning, Civil and Structural Engineering, Computer simulation, Mechanical Engineering, Bolted-flange, [PHYS.MECA]Physics [physics]/Mechanics [physics], Nuclear Energy and Engineering
Abstract: Special section of Proceedings of the 31st Symposium on Fusion Technology - 31st Symposium on Fusion Technology (SOFT2020) September 20-25, 2020, Dubrovnik, Croatie (Virtual event); International audience; In ITER, the ‘Pipe Forest (PF)’ is a network of pipes that connects the Ancillary Equipment Unit to the Test Blanket Module (TBM) at the level of the equatorial port-plug of the reactor prototype. The goal of ITER’s TBM program is to validate concepts to be adopted for the DEMO tritium Breeding Blankets. Different types of pipes are mounted on the port-plug among which those used for cooling or tritium processing. During plasma operation, the PF has to accommodate severe thermomechanical loads. It shall also provide protection from abnormal contamination and be designed to ease connection/disconnection operations. With numerical simulation, this work assesses the use of bolted flanges as an alternative to the welded solution to connect the PF on the TBMs inside the port cell environment. The proposed designs integrate metallic seals as well as an embedded cooling system in the flanges when necessary, to limit the temperature of the seals and the bolts and prevent irreversible damage. It is shown that bolted-flange junctions for the PF are a credible solution. Still, important stresses in the socket of the flanges are present but do not represent a problematic issue for dimensioning purposes, as they shall be accommodated with a small amount of plastic strain.
Published: 2021

26. Uranium solubility and speciation in reductive soda-lime aluminosilicate glass melts

Author: Tonya Vitova, S. Bahl, Laurent Tissandier, Annabelle Laplace, Etienne Deloule, Pierrick Chevreux, Fabienne Le Guyadec, Département de recherche sur les technologies pour l'enrichissement, le démantèlement et les déchets (DE2D), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Centre de Recherches Pétrographiques et Géochimiques (CRPG), Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Karlsruhe Institute of Technology (KIT), Département de recherche sur les procédés pour la mine et le recyclage du combustible (DMRC), European Project: 323300,EC:FP7:Fission,FP7-Fission-2012,TALISMAN(2013), and Département de recherche sur les Procédés et Matériaux pour les Environnements complexes (DPME)
Subjects: Nuclear and High Energy Physics, Materials science, Sodium oxide, Analytical chemistry, chemistry.chemical_element, 02 engineering and technology, Aluminosilicate glass melt, [CHIM.INOR]Chemical Sciences/Inorganic chemistry, 01 natural sciences, Redox, 010305 fluids & plasmas, chemistry.chemical_compound, Mineral redox buffer, Oxidation state, Aluminosilicate, 0103 physical sciences, Oxidation states, General Materials Science, Solubility, Uranium, 021001 nanoscience & nanotechnology, Alkali metal, Nuclear Energy and Engineering, chemistry, 13. Climate action, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], 0210 nano-technology, HR-XANES
Abstract: International audience; Uranium solubility in aluminosilicate melts of the Na$_2$O-CaO-Al$_2$O$_3$ -SiO$_2$ system with two different Na/Ca ratios was studied at temperatures of 1250–1400 °C and under various redox conditions. A closed thermochemical reactor was used to control the alkali metal activity (sodium oxide content) and the oxygen fugacity imposing the reducing environment on the glass melt (10$^{−5}$ atm < fO$_2$ < 10$^{−15}$ atm). The compositions of the quenched glasses were analyzed by scanning electron microscopy and electron probe microanalysis. It appeared that uranium solubility decreased with decreasing oxygen fugacity, elucidating the roles of the different valences of uranium. To account for the respective effects of theses valences, we proposed a method to determine the proportion of each uranium oxidation state in the glass sample. The coexisting U$^{VI}$, U $^V$, and U$^{IV}$ species have been characterized for the first time in glass samples using U M$_4$ edge high energy resolution X-ray absorption near-edge structure. Results showed that the lowest solubility values, of approximately 1 mol% UO$_2$ , were obtained under strongly reducing conditions, and thus with U$^{IV}$ as the main valence. Under higher oxygen fugacity, uranium solubility was controlled and drastically enhanced by the U$^{VI}$ concentration in the melt.
Published: 2021

27. Oxygen Bubble Formation in a Glass Melt in the context of Nuclear Waste Vitrification

Author: Luiz Pereira, Annabelle Laplace, Franck Pigeonneau, Pigeonneau, Franck, Département de recherche sur les technologies pour l'enrichissement, le démantèlement et les déchets (DE2D), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Centre de Mise en Forme des Matériaux (CEMEF), MINES ParisTech - École nationale supérieure des mines de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Département de recherche sur les Procédés et Matériaux pour les Environnements complexes (DPME), and Mines Paris - PSL (École nationale supérieure des mines de Paris)
Subjects: [CHIM.INOR] Chemical Sciences/Inorganic chemistry, [PHYS.MECA.MEFL] Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph], [PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph], [CHIM.INOR]Chemical Sciences/Inorganic chemistry
Abstract: International audience; This work takes place in the framework of nuclear waste vitrification and it deals with gas production occurring during the high-temperature process. We have focused on molecular oxygen (O2) produced by redox reactions of multivalent elements. This phenomenon is also relevant to further natural and industrial systems. Our aim is to understand the mechanisms of oxygen bubble formation and growth, and how they are linked to redox reactions that occur during nuclear waste vitrification. We have performed different physico-chemical characterizations to support the understanding of bubble formation in the mentioned context. Experimental and numerical results of mass transfer between an isolated oxygen bubble and the melt, at varying content of the multivalent oxide (% Ce2O3) and varying oxygen fugacity (fO2) are firstly presented. The results indicate that the presence of the multivalent element significantly enhances mass transfer from bubbles to melt, most acutely at reduced conditions and high contents. We further investigated a bubble population in a simplified nuclear waste glass melt. The melting of a granular starting glass, composed of glass beads, leads to a bubble population formed mainly due to air trapping. By assuming that the bubble dynamics is driven by their residence time in the crucible, the overall dynamics at various temperatures can be rationalized, scaled, and generalized.
Published: 2021

28. Alpha dose rate and alpha decay dose impacts on the residual alteration rate regime of HLW nuclear glasses

Author: Tribet, Magaly, MARQUES, Caroline, MOUGNAUD, Sarah, BROUDIC, Veronique, Jegou, Christophe, Peuget, Sylvain, Département de recherche sur les Procédés et Matériaux pour les Environnements complexes (DPME), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), and Département de recherche sur les technologies pour l'enrichissement, le démantèlement et les déchets (DE2D)
Subjects: Borosilicate glass, leaching, doped glass, radiolysis, [CHIM.INOR]Chemical Sciences/Inorganic chemistry, alpha dose rate, alpha decay dose, residual rate
Abstract: International audience; The long-term behavior of high-level nuclear glass subjected to alpha radiation by long-life minor actinides must be investigated with respect to geological disposal. This study focuses on the effects of alpha radiation on the chemical reactivity of R7T7-type glasses with pure water, mainly on the residual alteration rate regime, by considering separately the alpha dose rate and the alpha decay dose. Old SON68 glasses doped with $^(238/239)$PuO2 or $^(244)$CmO2 were studied in order to simulate high alpha dose rates corresponding to an early water ingress and also high level of alpha decay doses corresponding to long-term disposal conditions. A part of the $^(238/239)$Pu-doped glass block was annealed to fully recover the irradiation induced damage accumulated since the glass fabrication and to dissociate the effect of the alpha dose rate from the one of alpha decay dose. The glasses were then leached under static conditions in argon atmosphere at 90°C for several years. The results showed that the residual alteration rate is not impacted by the alpha dose rate parameter on a wide range of the dose rate values expected under disposal conditions, even in the eventuality of an early water ingress. It means that a SON68-type glass remained poorly sensitive to the alpha particle energy deposition at the glass-water interface. However, the residual alteration rate of the damaged $^(238/239)$Pu-doped glass was enhanced compared to the one of the annealed glass. This result is in agreement with the one obtained on the $^(244)$Cm-doped glass, and also with the literature about simplified glasses externally irradiated, indicating that the ballistic effects of the recoil nuclei are thus responsible for this increase of the residual alteration rate. A link between the glass structure and its leaching behavior is evidenced on these radioactive glasses and the role of the reactive interface is highly suspected.
Published: 2021

29. Transformations physico-chimiques du ruthénium lors de la vitrification des déchets nucléaires

Author: Laurin, Cloé, Département de recherche sur les technologies pour l'enrichissement, le démantèlement et les déchets (DE2D), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Université Montpellier, Olivier Pinet, Michael J. Toplis, STAR, ABES, and Département de recherche sur les Procédés et Matériaux pour les Environnements complexes (DPME)
Subjects: Redox, Cinétique, Kinetics, [PHYS.NEXP] Physics [physics]/Nuclear Experiment [nucl-ex], Verre, Ruthénium, Glass melt, Thermodynamics, Platinoïdes, Platinum group metals, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Thermodynamique, Ruthenium
Abstract: In France, fission products (including ruthenium) and minor actinides, which make up the high-level radioactive waste, are extracted from spent nuclear fuel and then vitrified. During the vitrification process, this waste is melted with a glass frit and creates chemical bonds with vitreous network forming cations. Unlike the other fission products or minor actinides, ruthenium is poorly soluble in the glass melt. It precipitates mainly as RuO2 needles and rarely as Ru0. These ruthenium particles modify the glass melt properties (rheology, electrical conductivity) and play a key role in the nuclear waste vitrification process. Because the properties of RuO2 and Ru0 are different, Ru0 particles are expected to have a greater impact on the process. The purpose of this study is thus to predict ruthenium speciation during nuclear waste vitrification. To meet this goal, an approach both theoretical (Calphad calculations) and experimental is implemented. First, it is implement under gaseous conditions, where the oxygen pressure of the chemical system is known and constant with temperature. Then, it is implemented in glass melts. In the melt, the oxygen pressure of the chemical system is dependent of temperature and glass composition, and is variable. The calculations and the experiments performed enable the determination of thermodynamic conditions of temperature and oxygen partial pressure leading to the RuO2 reduction into Ru0, the comprehension of the reduction mechanisms in glass melts, and the explanation of ruthenium particles morphologies. Kinetic limitations for the reach of thermodynamic equilibria are also studied. The oxidation kinetics of Ru0 into RuO2 depends on glass melt composition., En France, les produits de fission (dont le ruthénium) et les actinides mineurs, déchets ultimes de haute activité provenant du combustible nucléaire usé, sont vitrifiés. Ils forment des liaisons chimiques avec les formateurs du réseau vitreux apportés par les adjuvants de vitrification. Le ruthénium, contrairement aux autres radionucléides, est très peu soluble dans la fonte verrière. Il précipite sous forme d’aiguilles de RuO2 et de manière exceptionnelle sous forme Ru0. Ces particules insolubles modifient les propriétés physiques de la fonte (rhéologie, conductivité électrique) et jouent donc un rôle clé dans le procédé de vitrification des déchets nucléaires. Du fait des propriétés différentes de RuO2 et Ru0, l’impact de Ru0 est attendu plus important que celui de RuO2. L’objectif de cette thèse est alors de prédire la spéciation du ruthénium lors de la vitrification des déchets nucléaires. Une double approche, théorique d’une part (calculs Calphad), expérimentale d’autre part est proposée. Dans un premier temps, cette double approche est appliquée sous atmosphère gazeuse dans laquelle les conditions de p(O2) sont connues et constantes avec la température. Dans un second temps, elle est appliquée dans des fontes verrières, dans lesquelles la p(O2) du système est subie et dépendante de nombreux paramètres (température, composition du verre…). La confrontation des deux approches permet de déterminer les conditions thermodynamiques de température et de pression partielle en oxygène pouvant conduire à la réduction de RuO2 en Ru0, de comprendre les mécanismes de cette réduction dans les fontes verrières, et d’expliquer les morphologies des particules de ruthénium observées. Au-delà des considérations thermodynamiques, les limitations cinétiques à l’atteinte des équilibres sont également étudiées. Les résultats montrent que la cinétique d’oxydation de Ru0 en RuO2 dépend de la composition de la fonte verrière.
Published: 2020

30. Dissociation mechanisms of dissolved alkali silicates in sodium hydroxide

Author: Roland J.-M. Pellenq, Arnaud Poulesquen, Romain Dupuis, Jean-Baptiste Champenois, Multiscale Material Science for Energy and Environment (MSE 2), Massachusetts Institute of Technology (MIT), Laboratoire d’étude des Ciments et Bitumes pour le Conditionnement (LCBC), Département de recherche sur les Procédés et Matériaux pour les Environnements complexes (DPME), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), ANR-15-CE07-0013,DYNAMISTE,Dynamique de fluides Alumino-Silicatés(2015), and Département de recherche sur les technologies pour l'enrichissement, le démantèlement et les déchets (DE2D)
Subjects: Depolymerization, Inorganic chemistry, 02 engineering and technology, 010402 general chemistry, 021001 nanoscience & nanotechnology, Alkali metal, 01 natural sciences, Silicate, Dissociation (chemistry), 0104 chemical sciences, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, chemistry.chemical_compound, General Energy, chemistry, Sodium hydroxide, Physical and Theoretical Chemistry, 0210 nano-technology
Abstract: International audience; Recent accelerated simulations of the decondensation of silicates by sodium hydroxide open a window on understanding complex mechanisms of the depolymerization of silicate chains. Herein, complex mechanisms of decondensation that involve two water molecules (or OH$^–$ groups) are unveiled. The study of two different solutions, having the same chemical composition but in different concentration, help one to draw more general conclusions on the dissociation mechanism in silicate solutions. We find that the dissociation is not always assisted by single water molecules but that in about 20% of the cases two water molecules (or OH$^–$) are present in the near environment. The results underline the importance to consider explicit water solvent in which water molecules are reactive.
Published: 2020

31. Can a simple topological-constraints-based model predict the initial dissolution rate of borosilicate and aluminosilicate glasses?

Author: Stéphane Gin, J.M. Delaye, Mathieu Bauchy, Lu Deng, Mélanie Taron, Frédéric Angeli, Xiaonan Lu, Mengyi Wang, Nicolas Bisbrouck, Thibault Charpentier, Jincheng Du, Département de recherche sur les technologies pour l'enrichissement, le démantèlement et les déchets (DE2D), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Physics of Amorphous and Inorganic Solids Laboratory (PARISlab), University of California, Department of Materials Science and Engineering (DMSE), Massachusetts Institute of Technology (MIT), Department of Materials Science and Engineering, University of North Texas (UNT), Laboratoire Structure et Dynamique par Résonance Magnétique (LCF) (LSDRM), Nanosciences et Innovation pour les Matériaux, la Biomédecine et l'Energie (ex SIS2M) (NIMBE UMR 3685), Centre National de la Recherche Scientifique (CNRS)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, the Center for Performance and Design of Nuclear Waste Forms and Containers, an Energy Frontier Research Center funded by the U.S. Department of Energy (DOE), Office of Science, Basic Energy Sciences under Award # DESC0016584, the Department of Energy’s Office of Nuclear Energy’s Nuclear Energy University Programs (Award #18–15020), the National Science Foundation (Grant No. 1562066), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Département de recherche sur les Procédés et Matériaux pour les Environnements complexes (DPME), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Rayonnement Matière de Saclay (IRAMIS), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Materials science, Series (mathematics), Borosilicate glass, Materials Science (miscellaneous), Empirical modelling, 02 engineering and technology, [CHIM.MATE]Chemical Sciences/Material chemistry, Orders of magnitude (numbers), 010402 general chemistry, 021001 nanoscience & nanotechnology, Topology, 01 natural sciences, 0104 chemical sciences, Chemistry (miscellaneous), Aluminosilicate, Atom, lcsh:TA401-492, Materials Chemistry, Ceramics and Composites, lcsh:Materials of engineering and construction. Mechanics of materials, 0210 nano-technology, Envelope (mathematics), Dissolution
Abstract: Tuning glass composition to obtain targeted properties generally relies on empirical approaches. However, a deep understanding of the physical and chemical mechanisms linking glass composition to its structure and properties would enable developing reliable predictive models. Indeed, although empirical models are usually able to interpolate composition–property relationships within a given compositional envelope, they often fail at extrapolating predictions far from their training domain. Here, as an alternative route to empirical models, we show that a structural descriptor based on the number of topological constraints per atom can be used to predict the initial dissolution rate of aluminosilicate and borosilicate glasses after being parameterized on different families of glasses (specific series of borosilicate glasses). Sixteen glasses belonging to these families were studied and their initial dissolution rates were determined at 90 °C and pH90 °C = 9, covering rates spanning over 5 orders of magnitude. The model based on topological constraints was trained based on seven select borosilicate glasses (R2 = 0.997) and used to predict the dissolution rate of nine additional borosilicate and aluminosilicate glasses. We show that, provided that corrections are made for high alkali content glasses that dissolve incongruently (preferential release of Na), the model gives reasonable predictions, even far from its training domain.
Published: 2020

32. A general mechanism for gel layer formation on borosilicate glass under aqueous corrosion

Author: Anamul H. Mir, Alkiviadis Gourgiotis, Amreen Jan, Sebastien N. Kerisit, E. Chauvet, Stéphane Gin, J.M. Delaye, Y. De Puydt, Département de recherche sur les technologies pour l'enrichissement, le démantèlement et les déchets (DE2D), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), School of Computing and Engineering, University of Huddersfield, TESCAN Analytics, Institut de Radioprotection et de Sûreté Nucléaire (IRSN), Pacific Northwest National Laboratory (PNNL), and Département de recherche sur les Procédés et Matériaux pour les Environnements complexes (DPME)
Subjects: Mineral, Materials science, Silicon, Borosilicate glass, Aqueous corrosion, chemistry.chemical_element, 02 engineering and technology, [CHIM.MATE]Chemical Sciences/Material chemistry, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, 0104 chemical sciences, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, Corrosion, Secondary ion mass spectrometry, General Energy, chemistry, Chemical engineering, Physical and Theoretical Chemistry, 0210 nano-technology, Dissolution, Layer (electronics)
Abstract: International audience; Mineral and glass dissolution is a scientific topic deeply investigated but incompletely understood and of a great interest for the geochemical and materials science communities. If the interfacial dissolution/reprecipitation mechanism seems to be applicable to most of silicate minerals, the debate remains open concerning glass. Here we studied two model glasses, a ternary borosilicate (CJ1) and the same glass doped with 4.1 mol % of Al2O3 (CJ2). The two glasses were altered at 90°C, pH 9, and in conditions far and close to saturation with respect to amorphous silica, to determine the initial and residual rates. Moreover, a specific experiment was conducted for a short duration with a solution highly enriched with 18O and 29Si isotopes to understand how passivating gels form. SEM, TEM and ToF-SIMS characterization, along with Monte Carlo simulations were used to understand the rate limiting reactions at play and infer the role of Al. We show that Al yields a slower matrix dissolution in dilute conditions. However, it slows down the formation and the maturation of the passivating gel and favors alteration by partial hydrolysis of Si and Al entities followed by in-situ reorganization/relaxation into a porous network. Unexpectedly, CJ1 experienced both interfacial dissolution/reprecipitation and partial hydrolysis followed by in situ reorganization of the silicate network during the course of a single experiment. This study offers a unified concept that can pave the way for the future development of a predictive kinetic model based on a detailed description of bond breaking and bond forming as a function of glass composition and alteration conditions.
Published: 2020

33. Rheoacoustic Gels: Tuning Mechanical and Flow Properties of Colloidal Gels with Ultrasonic Vibrations

Author: Gibaud, Thomas, Dagès, Noémie, Lidon, Pierre, Jung, Guillaume, Ahouré, L. Christian, Sztucki, Michael, Poulesquen, Arnaud, Hengl, Nicolas, Pignon, Frédéric, Manneville, Sébastien, Laboratoire de Physique de l'ENS Lyon (Phys-ENS), École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), European Synchrotron Radiation Facility (ESRF), Laboratoire d’étude des Ciments et Bitumes pour le Conditionnement (LCBC), Département de recherche sur les technologies pour l'enrichissement, le démantèlement et les déchets (DE2D), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Laboratoire Rhéologie et Procédés (LRP), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA), and MultiScale Materials Science for Energy and Environment, Joint MIT-CNRS Laboratory
Subjects: [SPI.FLUID]Engineering Sciences [physics]/Reactive fluid environment, Physics, QC1-999, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], Soft Condensed Matter (cond-mat.soft), FOS: Physical sciences, Condensed Matter - Soft Condensed Matter, [PHYS.COND.CM-SCM]Physics [physics]/Condensed Matter [cond-mat]/Soft Condensed Matter [cond-mat.soft], ComputingMilieux_MISCELLANEOUS, [SPI.MECA.MEFL]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Fluids mechanics [physics.class-ph]
Abstract: Colloidal gels, where nanoscale particles aggregate into an elastic yet fragile network, are at the heart of materials that combine specific optical, electrical and mechanical properties. Tailoring the viscoelastic features of colloidal gels in real-time thanks to an external stimulus currently appears as a major challenge in the design of "smart" soft materials. Here we introduce "rheo-acoustic" gels, a class of materials that are sensitive to ultrasonic vibrations. By using a combination of rheological and structural characterization, we evidence and quantify a strong softening in three widely different colloidal gels submitted to ultrasonic vibrations (with submicron amplitude and frequency 20-500 kHz). This softening is attributed to micron-sized cracks within the gel network that may or may not fully heal once vibrations are turned off depending on the acoustic intensity. Ultrasonic vibrations are further shown to dramatically decrease the gel yield stress and accelerate shear-induced fluidization. Ultrasound-assisted fluidization dynamics appear to be governed by an effective temperature that depends on the acoustic intensity. Our work opens the way to a full control of elastic and flow properties by ultrasonic vibrations as well as to future theoretical and numerical modeling of such rheo-acoustic gels., Comment: 21 pages, 14 figures
Published: 2020

34. Redox behavior of ruthenium in nuclear glass melt: ruthenium dioxide reduction reaction

Author: Stéphane Gossé, Michael J. Toplis, Sylvain Mure, E. Brackx, Julia Agullo, Cloé Laurin, Annabelle Laplace, Elise Régnier, Olivier Pinet, Département de recherche sur les Procédés et Matériaux pour les Environnements complexes (DPME), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Service de la Corrosion et du Comportement des Matériaux dans leur Environnement (SCCME), Département de Physico-Chimie (DPC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Département de recherche sur les procédés pour la mine et le recyclage du combustible (DMRC), Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France, Département de recherche sur les technologies pour l'enrichissement, le démantèlement et les déchets (DE2D), and Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)
Subjects: Nuclear and High Energy Physics, Materials science, chemistry.chemical_element, 02 engineering and technology, [CHIM.INOR]Chemical Sciences/Inorganic chemistry, 01 natural sciences, 010305 fluids & plasmas, Autocatalysis, Redox, Rheology, 0103 physical sciences, thermodynamic modeling, General Materials Science, Vitrification, ruthenium, CALPHAD, Fission products, nuclear glass, 021001 nanoscience & nanotechnology, Decomposition, Ruthenium, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, Nuclear Energy and Engineering, Chemical engineering, chemistry, 13. Climate action, Particle, 0210 nano-technology
Abstract: International audience; Among platinoid fission products, ruthenium is a key element during the vitrification of high-level waste because it is poorly soluble in the glass matrix. It occurs mainly as RuO$_2$ particles and sometimes as Ru$^0$ particles in the glass melt and final cooled glass. Because the physical properties of ruthenium are very different from those of glass, the RuO$_2$ particles change the glass melt properties such as the rheology, thermal conductivity and electrical conductivity. In addition, because the Ru0 properties are even more distinct from the glass properties, glass melts can be more sensitive to the presence of Ru0 particles. Thus, ruthenium speciation, specifically the RuO$_2$ reduction into Ru$^0$, was investigated in air and glass environments, and the experimental results were compared to thermodynamic calculations (Calphad method).Under air conditions, the thermodynamic modeling and experimental results are in good agreement. They show a reduction of RuO$_2$ at 1403 °C and 1405 ± 7 °C, respectively. The experimental results indicate that the Ru$^0$ particle formation may result from an autocatalysis mechanism, which involves the gaseous species of ruthenium.In the investigated glass, the first Ru$^0$ particles appear at approximately 1280 °C. At 1280 °C < T < 1400 °C, only few particles are observed attributed to minor reduction phenomena: local redox reaction with iron or disproportionation reaction. At higher temperatures (T > 1400 °C), a much more significant reduction takes place. This one is attributed to the decomposition under temperature and oxygen pressure conditions, predicted by thermodynamic calculations. Based on the results obtained under air conditions, it is assumed that the reduction mechanism involves dissolved ruthenium species.
Published: 2020

35. New insights about the importance of the alteration layer/glass interface

Author: Jonathan A. Hinks, Sarah Mougnaud, Stephen E. Donnelly, Christophe Jégou, Anamul H. Mir, Célia Gillet, Sylvain Peuget, Magaly Tribet, Département de recherche sur les technologies pour l'enrichissement, le démantèlement et les déchets (DE2D), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), University of Huddersfield, and Département de recherche sur les Procédés et Matériaux pour les Environnements complexes (DPME)
Subjects: Materials science, 02 engineering and technology, 010402 general chemistry, 01 natural sciences, Amorphous materials, Radiation damage, Irradiation, Physical and Theoretical Chemistry, High-resolution transmission electron microscopy, Porosity, Dissolution, Radiation, 021001 nanoscience & nanotechnology, 0104 chemical sciences, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, Amorphous solid, Secondary ion mass spectrometry, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, General Energy, Chemical engineering, Leaching, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], Leaching (metallurgy), 0210 nano-technology, Layers
Abstract: International audience; This work addresses the impact of radiation damage on the leaching of international simple glass (ISG). Pristine and specimens irradiated with multi-energy Au ions were leached for 82 days at 90°C in pure water and pH 9 and regularly sampled. Samples leached for 13 and 58 days were characterized using transmission electron microscopy (TEM) to study the microstructure(s) of the alteration layers formed from the radiation-damaged and pristine glasses. Furthermore, a sample altered for 82 days was immersed in water enriched in isotopically tagged water molecules (H$_2$$^{18}$O) to study and compare the mobility and reactivity in the alteration layers formed on these glasses. The studies revealed that radiation damage diminished the chemical durability of the ISG glass since the beginning of the leaching experiment. Concomitantly, the formation of a non-porous alteration layer of about 237 nm after 13 days of leaching evolving into the formation of a nanoporous alteration layer of about 570 nm after 58 days of leaching was observed in the irradiated glasses. In contrast, a non-porous altered layer of about 138 nm only developed in the non-irradiated specimen altered for 58 days. Using energy-filtered transmission electron microscopy, the altered layers in all the cases were found to be depleted in boron, in agreement with the time of flight secondary ion mass spectroscopy studies. Despite pore formation, similar behaviour in the $^{18}$O — $^{16}$O exchanges (with respect to the uncertainties) was observed in the major part of the alteration layers whether formed from the irradiated or pristine ISG, leading to the conclusion that the greater alterability of the radiation-damaged ISG may not be due to the porosity. However, isotopic exchanges also revealed a significantly higher reactivity of the alteration-layer/glass interface for the irradiated glass. While these studies provide important insights about the role of porosity and radiation damages, they also highlight the complex nature of glass dissolution and, suggest that studies directed at alteration-layer/glass interface are needed to better understand and explain the mechanisms controlling the glass dissolution in the residual alteration rate regime.
Published: 2020

36. Synthesis of geopolymer emulsions

Author: Angélique Barneoud-Chapelier, Jérémy Causse, Arnaud Poulesquen, Laboratoire d’étude des Ciments et Bitumes pour le Conditionnement (LCBC), Département de recherche sur les Procédés et Matériaux pour les Environnements complexes (DPME), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Nanomatériaux pour l'Energie et le Recyclage (LNER), Institut de Chimie Séparative de Marcoule (ICSM - UMR 5257), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Département de recherche sur les technologies pour l'enrichissement, le démantèlement et les déchets (DE2D), and Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)
Subjects: Materials science, 02 engineering and technology, Hexadecane, [CHIM.INOR]Chemical Sciences/Inorganic chemistry, 010402 general chemistry, 01 natural sciences, DSC, chemistry.chemical_compound, Viscosity, Specific surface area, Geopolymer emulsions, General Materials Science, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], Porosity, Mechanical Engineering, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 0104 chemical sciences, Geopolymer, Compressive strength, chemistry, Chemical engineering, Mechanics of Materials, Volume fraction, Emulsion, 0210 nano-technology
Abstract: International audience; The understanding of geopolymer emulsion synthesis is a major issue for several industrial applications such as the formation of hierarchically porous material for filtration, lightweight materials for civil engineering or even the conditioning of radioactive mineral oil. The aim of this paper is to study model emulsions (hexadecane dispersed in Na or K-metakaolin based geopolymer) with the highest volume fraction of C16 incorporated. The influence of the viscosity of the geopolymer paste controlled by the water content was studied and results show that emulsions are unstable for a viscosity ratio ηd/ηc lower than 0.01. Up to 70% in volume of C16 was incorporated within the K-geopolymer and hierarchical porous network was thus obtained. After oil removal by solvent extraction, a monolith with a compressive strength of around 0.5–0.6 MPa was characterized in terms of pore size distribution and specific surface area.
Published: 2020

37. Experimental and numerical investigations of an oxygen single‐bubble shrinkage in a borosilicate glass‐forming liquid doped with cerium oxide

Author: Annabelle Laplace, Miroslava Vernerová, Franck Pigeonneau, Jaroslav Kloužek, Luiz Pereira, Département de recherche sur les technologies pour l'enrichissement, le démantèlement et les déchets (DE2D), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Centre de Mise en Forme des Matériaux (CEMEF), MINES ParisTech - École nationale supérieure des mines de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), University of Chemistry and Technology Prague (UCT Prague), Institute of Rock Structure and Mechanics of the Czech Academy of Sciences (IRSM / CAS), Czech Academy of Sciences [Prague] (CAS), Département de recherche sur les Procédés et Matériaux pour les Environnements complexes (DPME), and Mines Paris - PSL (École nationale supérieure des mines de Paris)
Subjects: Cerium oxide, Materials science, numerical analysis, Bubble, Thermodynamics, chemistry.chemical_element, 02 engineering and technology, Péclet number, 01 natural sciences, Physics::Fluid Dynamics, symbols.namesake, Mass transfer, glass melt, 0103 physical sciences, mass transfer, Materials Chemistry, Shrinkage, 010302 applied physics, Borosilicate glass, bubble, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Cerium, chemistry, redox, Ceramics and Composites, symbols, 0210 nano-technology, Dimensionless quantity
Abstract: International audience; The shrinkage of an oxygen single-bubble is investigated in a cerium-doped borosil-icate glass melt at 1150°C. Nine glass samples are synthesized and investigated, utilizing three different amounts of Ce2O3 and three different redox ratios (Ce-(III)/Ce total). Employing in-situ observation, the single-bubble behavior is recorded with a camera. For each glass melt, five experiments are performed with different initial bubble radii. The shrinkage rate (da/dt) depends strongly on the cerium content as well as the redox ratio. Numerical calculations are also conducted to support the understanding of the bubble shrinkage mechanism in the given cases. The model adequately estimates the experimental data for several cases, and an explanation is proposed for the cases, in which it does not. Moreover, we demonstrate, physically and mathematically, the influence of the initial radius of the bubble on the mass transfer between the rising bubble and the melt. We confirm the utilization of the "modified Péclet number", which is a dimensionless number that takes into consideration the influence of multivalent elements on mass transfer. Finally, we master the bubble shrinkage behavior by normalizing the experimental data employing a characteristic time for the mass transfer (&tau).
Published: 2020

38. Design and development of a portable beta spectrometer for 90Sr measurement in contaminated matrices

Author: Venara, Julien, Ben Mosbah, Mehdi, Mahe, Charly, Astier, Julien, Adera, Susanna, Cuozzo, Marie, Goudeau, Vincent, Département de recherche sur les technologies pour l'enrichissement, le démantèlement et les déchets (DE2D), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Département Technologie Nucléaire (DTN), CEA Le Ripault (CEA Le Ripault), Direction des Applications Militaires (DAM), and Département de recherche sur les Procédés et Matériaux pour les Environnements complexes (DPME)
Subjects: $^(90)$Sr, Scintillation detector, Beta spectrometry, [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], Contaminated matrices, Monte Carlo, Decommissioning
Abstract: International audience; Determining the nature and activity of radionuclides is an important task in the nuclear industry. Pure β- emitters are hard to characterize because the mean free path of electrons in dense matter is very short. Most measurement techniques are therefore based on destructive laboratory analyses. This article presents a non-destructive approach based on a portable β- spectrometer, designed to provide qualitative and quantitative information on pure β- emitters, notably 90Sr. Building on existing methods focused on the measurement of 90Sr activity in natural soil contaminated by the Chernobyl accident, the aim of this project is to develop a detector for the radiological characterization of different types of contaminated matrices, in particular the contaminated concrete structures typically found in nuclear facilities. A measurement device equipped with an EJ200 plastic scintillator was designed using Monte Carlo simulations with the MCNP6 and PENELOPE calculation codes. The energy calibration and the response of the detector were determined using experimental measurements and MCNP simulations of laboratory configurations of standard β- sources. These data were used to validate the model of the detector, as well as to determine calibration factors by numerical simulation for various on-site measurement configurations. The device was then used to characterize samples of sand from a decommissioning site in France (Fontenay-aux-Roses). The resulting 90Sr activities are within experimental uncertainties of those obtained using destructive measurements. These results are promising for wider applications on nuclear decommissioning sites.
Published: 2020

39. AVM nuclear glass/steel/claystone system altered by Callovo–Oxfordian poral water with and without cement–bentonite grout at 70°C

Author: Philippe Dillmann, Florent Tocino, Charly Carrière, Christelle Martin, Alexis Delanoë, Stéphane Gin, Delphine Neff, Nicolas Michau, Yannick Linard, Laboratoire Archéomatériaux et Prévision de l'Altération (LAPA - UMR 3685), Nanosciences et Innovation pour les Matériaux, la Biomédecine et l'Energie (ex SIS2M) (NIMBE UMR 3685), Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), IRAMAT - Laboratoire Métallurgies et Cultures (IRAMAT - LMC), Institut de Recherches sur les Archéomatériaux (IRAMAT), Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Université Bordeaux Montaigne-Université de Technologie de Belfort-Montbeliard (UTBM)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Université Bordeaux Montaigne-Université de Technologie de Belfort-Montbeliard (UTBM), Agence Nationale pour la Gestion des Déchets Radioactifs (ANDRA), Matériaux et Mécanique des Composants (EDF R&D MMC), EDF R&D (EDF R&D), EDF (EDF)-EDF (EDF), Département de recherche sur les technologies pour l'enrichissement, le démantèlement et les déchets (DE2D), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), CEA, CNRS, ADEME, Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Université de Technologie de Belfort-Montbeliard (UTBM)-Université d'Orléans (UO)-Université Bordeaux Montaigne (UBM)-Centre National de la Recherche Scientifique (CNRS)-Université de Technologie de Belfort-Montbeliard (UTBM)-Université d'Orléans (UO)-Université Bordeaux Montaigne (UBM)-Centre National de la Recherche Scientifique (CNRS), and Département de recherche sur les Procédés et Matériaux pour les Environnements complexes (DPME)
Subjects: Materials science, 02 engineering and technology, 010501 environmental sciences, engineering.material, 01 natural sciences, Corrosion, steel corrosion, cement-bentonite grout, Materials Chemistry, Environmental Chemistry, 0105 earth and related environmental sciences, Cement, Mechanical Engineering, Grout, Metallurgy, Metals and Alloys, General Medicine, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Surfaces, Coatings and Films, Mechanics of Materials, AVM nuclear glass, Bentonite, engineering, 0210 nano-technology, glass/steel interactions
Abstract: International audience; The effect of a cement–bentonite grout material was studied through glass/steel interactions. Hence, two experimental mock-ups, consisting of a “sandwich” of four materials in contact, stainless steel/AVM glass/AVM glass/P285NH steel, were leached by Callovo–Oxfordian poral water at 70°C for 1 year. CBG material was added for one experiment, whereas the second one was CBG-free. Chemical and structural analyses (scanning electron microscopy–energy-dispersive X-ray spectroscopy, Raman), performed mainly at the AVM glass/P285NH interface, evidenced a comparable alteration with and without the CBG. Indeed, its presence did not impact the gel formation by hydrolysis/condensation mechanism. For both experiments, the glass alteration rates corresponded to $r_0^{Cox,70°C}\over 32$, highlighting a kinetic rate drop after a 1-year leaching period. However, the CBG impacted the pH solution initially buffered by the claystone, promoting precipitation of Mg/Fe-rich silicates on the gel surface. Regarding P285NH corrosion, no major difference was observed with the CBG. Steel corrosion layers in both experiments were Si-free, and the corrosion rates were similar. Therefore, after 1 year at 70°C, the CBG had a limited effect on the glass/carbon steel interactions.
Published: 2020

40. Chemo-Hydro-Mechanical analysis of Bituminized Waste swelling due to water uptake: Experimental and model comparisons

Author: Arnaud Poulesquen, Jean-Baptiste Champenois, Sofia M'Jahad, G Melot, Sylvie Granet, Patrick Dangla, Institut des Sciences de la mécanique et Applications industrielles (IMSIA - UMR 9219), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École Nationale Supérieure de Techniques Avancées (ENSTA Paris)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay-EDF R&D (EDF R&D), EDF (EDF)-EDF (EDF), Laboratoire Navier (NAVIER UMR 8205), École des Ponts ParisTech (ENPC)-Centre National de la Recherche Scientifique (CNRS)-Université Gustave Eiffel, Laboratoire d’étude des Ciments et Bitumes pour le Conditionnement (LCBC), Département de recherche sur les technologies pour l'enrichissement, le démantèlement et les déchets (DE2D), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École Nationale Supérieure de Techniques Avancées (ENSTA Paris)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-EDF R&D (EDF R&D), and Département de recherche sur les Procédés et Matériaux pour les Environnements complexes (DPME)
Subjects: Nuclear and High Energy Physics, Osmosis, Constitutive equation, 02 engineering and technology, 01 natural sciences, 7. Clean energy, Homogenization (chemistry), 010305 fluids & plasmas, Diffusion, Chemo-Hydro-Mechanical analysis, 0103 physical sciences, General Materials Science, Porosity, Swelling, Dissolution, Petroleum engineering, Radioactive waste, [CHIM.MATE]Chemical Sciences/Material chemistry, Permeation, 021001 nanoscience & nanotechnology, Spent nuclear fuel, Nuclear Energy and Engineering, Bituminized Waste Products (BWP), Environmental science, Leaching (metallurgy), 0210 nano-technology
Abstract: International audience; This paper presents a numerical model developed to reproduce the behaviour of French simplified Bituminized Waste Products (BWP) during a leaching test. The model is calibrated on experimental data sets. BWP were mainly produced during industrial reprocessing of nuclear spent fuel and are classified as low or intermediate activity long lived radioactive waste. Geological disposal is the reference solution for intermediate level long-lived BWP. Under geological disposal facility conditions, and after a long period of time, BWP will undergo water re-saturation from the host rock. A chemo-hydro-mechanical numerical model has been implemented with a finite element scheme to model BWP behaviour under such conditions. The constitutive model takes into account the impact of dissolution, permeation, diffusion and osmosis. Original evolution laws of diffusion coefficient and permeability as a function of the porosity are proposed. Specific mechanical model is proposed including Mori-Tanaka homogenization law. To simulate the hydration of the material, an original and simple method is proposed, avoiding costly two-phase flow resolution and complex calibration of the related parameters. This model was mainly used to reproduce the evolution of the amount of both water absorbed and salt leached by the sample during unconfined water up-taking tests. The calibration is based on experimental data obtained on French simplified BWP containing one highly soluble salt. Water uptake could generate swelling mainly due to osmosis.
Published: 2020

41. Behaviour of magnesium phosphate cement-based materials under gamma and alpha irradiation

Author: C. Cau Dit Coumes, S. Parraud, S. Esnouf, Jean Philippe Renault, O. Farcy, J. Sanchez-Canet, D. Chartier, Pascal Antonucci, David Lambertin, H. Lamotte, Laboratoire d’étude des Ciments et Bitumes pour le Conditionnement (LCBC), Département de recherche sur les Procédés et Matériaux pour les Environnements complexes (DPME), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Service d'Etudes du Comportement des Radionucléides (SECR), Département de Physico-Chimie (DPC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Laboratoire Interdisciplinaire sur l'Organisation Nanométrique et Supramoléculaire (LIONS), Nanosciences et Innovation pour les Matériaux, la Biomédecine et l'Energie (ex SIS2M) (NIMBE UMR 3685), Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Andra dans le cadre des 'Investissements d'Avenir' (MATRICE and MACH3 projects), Département de recherche sur les technologies pour l'enrichissement, le démantèlement et les déchets (DE2D), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)
Subjects: Nuclear and High Energy Physics, Materials science, Cement, Waste conditioning, chemistry.chemical_element, 02 engineering and technology, Fly ash, 01 natural sciences, 010305 fluids & plasmas, law.invention, law, 0103 physical sciences, Radiolysis, [CHIM]Chemical Sciences, General Materials Science, Gamma, Magnesium phosphate, Alpha, K-struvite, Magnesium, Slag, Radioactive waste, 021001 nanoscience & nanotechnology, Wasteform, Portland cement, Getter, Nuclear Energy and Engineering, chemistry, Chemical engineering, Dihydrogen, visual_art, visual_art.visual_art_medium, Irradiation, Mortar, 0210 nano-technology
Abstract: Stabilization and solidification of low- and intermediate-level radioactive waste using Portland cement, possibly blended with fly ash or blastfurnace slag, is a well-established practice. However, when the waste contains high amounts of alpha emitters, this solution can be restricted by the strong release of radiolytic gases, wherein H2 is the most abundant. This work investigates the interest of using magnesium potassium phosphate cement (MPC), a binder with a high chemical water demand, as a possible substitute to Portland cement (PC). The radiolytic gas production of PC and MPC pastes and mortars is determined under external gamma and internal alpha irradiation. The H2 radiolytic yield of MPC materials is found to be 2 to 3 times smaller than that of PC references, provided that the main part of the mixing water is consumed by K-struvite formation. Moreover, gamma irradiation of a MPC mortar up to an integrated dose of 10 MGy has no significant influence on its mechanical strength (flexural, compressive) nor on its mineralogy. MPC materials are thus potential candidates for the conditioning of high amounts of radioactivity with limited H2 release. The H2 production of MPC materials can be reduced further by adding radical scavengers or H2 getters within the matrix. However, other radiolytic gases such as O2 are often produced, making these solutions potentially less attractive considering the concern of pressure build-up within the cemented waste package.
Published: 2020

42. Aluminum incorporation into magnesium silicate hydrate (M-S-H)

Author: Ellina Bernard, Barbara Lothenbach, Céline Cau-dit-Coumes, Isabelle Pochard, Daniel Rentsch, Swiss Federal Laboratories for Materials Science and Technology [Dübendorf] (EMPA), Institute of Geological Sciences [Bern], University of Bern, Département de recherche sur les technologies pour l'enrichissement, le démantèlement et les déchets (DE2D), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC), Univers, Transport, Interfaces, Nanostructures, Atmosphère et environnement, Molécules (UMR 6213) (UTINAM), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC), and Département de recherche sur les Procédés et Matériaux pour les Environnements complexes (DPME)
Subjects: Thermogravimetric analysis, Materials science, Magnesium, 0211 other engineering and technologies, chemistry.chemical_element, 690 Building & construction, 02 engineering and technology, Building and Construction, 021001 nanoscience & nanotechnology, Silicate, chemistry.chemical_compound, chemistry, Octahedron, Polymerization, Transmission electron microscopy, Aluminium, 021105 building & construction, 550 Earth sciences & geology, [CHIM]Chemical Sciences, General Materials Science, 0210 nano-technology, Hydrate, ComputingMilieux_MISCELLANEOUS, Nuclear chemistry
Abstract: The incorporation of aluminum in magnesium silicate hydrate (M-S-H) phases was investigated. Magnesium (alumino) silicate hydrate (M-(A-)S-H) with Mg/Si ratios equal to 1.1 or 1.7 and Al/Si ranging from 0 to 0.2 were synthetized in batch experiments and equilibrated at 20, 50 and 70 °C. pH values between 9 and 10.5 were observed and aluminum up to Al/Si ~0.15–0.18 was incorporated in M-(A-)S-H. Thermogravimetric analysis (TGA), X-ray diffraction (XRD), X-ray pair distribution function (PDF) analysis, transmission electron microscopy (TEM), 29Si and 27Al MAS NMR data showed that the M-(A-)S-H phases formed were similar to M-S-H with limited coherent size and a comparable polymerization degree of the tetrahedral silicates. Aluminum was incorporated in both tetrahedral and octahedral sites of M-S-H, while no aluminum was present as exchangeable cation on the surface sites.
Published: 2020
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43. Time-connectivity superposition and the gel/glass duality of weak colloidal gels

Author: Michela Geri, Donatien Gomes Rodrigues, Thibaut Divoux, Arnaud Poulesquen, Jan Ilavsky, Matthew G. Frith, Bavand Keshavarz, Jean-Baptiste Champenois, Gareth H. McKinley, Department of Mechanical Engineering [Massachusetts Institute of Technology] (MIT-MECHE), Massachusetts Institute of Technology (MIT), Laboratoire d’étude des Ciments et Bitumes pour le Conditionnement (LCBC), Département de recherche sur les Procédés et Matériaux pour les Environnements complexes (DPME), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Advanced Photon Source [ANL] (APS), Argonne National Laboratory [Lemont] (ANL)-University of Chicago-US Department of Energy, MultiScale Materials Science for Energy and Environment, Aix Marseille Université (AMU)-Massachusetts Institute of Technology (MIT)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique de l'ENS Lyon (Phys-ENS), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), ANR-15-CE07-0013,DYNAMISTE,Dynamique de fluides Alumino-Silicatés(2015), Département de recherche sur les technologies pour l'enrichissement, le démantèlement et les déchets (DE2D), École normale supérieure - Lyon (ENS Lyon)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon
Subjects: Gel point, Multidisciplinary, Materials science, 02 engineering and technology, 021001 nanoscience & nanotechnology, Microstructure, 01 natural sciences, Viscoelasticity, Condensed Matter::Soft Condensed Matter, Superposition principle, Colloid, Orders of magnitude (time), Chemical physics, 0103 physical sciences, Physical Sciences, 010306 general physics, 0210 nano-technology, Spectroscopy, [PHYS.COND.CM-SCM]Physics [physics]/Condensed Matter [cond-mat]/Soft Condensed Matter [cond-mat.soft], Brownian motion
Abstract: International audience; Colloidal gels result from the aggregation of Brownian particles suspended in a solvent. Gelation is induced by attractive interactions between individual particles that drive the formation of clusters, which in turn aggregate to form a space-spanning structure. We study this process in aluminosilicate colloidal gels through time-resolved structural and mechanical spectroscopy. Using the time-connectivity superposition principle a series of rapidly-acquired linear viscoelastic spectra, measured throughout the gelation process by applying an exponential chirp protocol, are rescaled onto a universal master curve that spans over eight orders of magnitude in reduced frequency. This analysis reveals that the underlying relaxation time spectrum of the colloidal gel is symmetric in time with power-law tails characterized by a single exponent that is set at the gel point. The microstructural mechanical network has a dual character; at short length scales and fast times appearing glassy, whereas at longer times and larger scales it is gel-like. These results can be captured by a simple three-parameter constitutive model and demonstrate that the microstructure of a mature colloidal gel bears the residual skeleton of the original sample-spanning network that is created at the gel point. Our conclusions are confirmed by applying the same technique to another well-known colloidal gel system composed of attractive silica nanoparticles. The results illustrate the power of the time-connectivity superposition principle for this class of soft glassy materials and provide a new compact description for the dichotomous viscoelastic nature of weak colloidal gels
Published: 2020

44. Many-body effects at the origin of structural transitions in B2O3

Author: Baroni, Axelle, Pacaud, Fabien, Salanne, Mathieu, Micoulaut, Matthieu, Delaye, Jean-Marc, Zeidler, Anita, Salmon, Philip, Ferlat, Guillaume, PHysicochimie des Electrolytes et Nanosystèmes InterfaciauX (PHENIX), Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Physicochimie des Electrolytes, Colloïdes et Sciences Analytiques (PECSA), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC), Laboratoire de Physique Théorique de la Matière Condensée (LPTMC), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire des Matériaux et Procédés Actifs (LMPA), Département de recherche sur les technologies pour l'enrichissement, le démantèlement et les déchets (DE2D), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Department of Physics [Bath], University of Bath [Bath], Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de recherche pour le développement [IRD] : UR206-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS), ferlat, guillaume, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Département de recherche sur les Procédés et Matériaux pour les Environnements complexes (DPME), and Muséum national d'Histoire naturelle (MNHN)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de recherche pour le développement [IRD] : UR206-Centre National de la Recherche Scientifique (CNRS)
Subjects: [PHYS]Physics [physics], [CHIM.MATE] Chemical Sciences/Material chemistry, [CHIM.MATE]Chemical Sciences/Material chemistry, 6470kj, [PHYS.COND.CM-MS] Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], [PHYS] Physics [physics], [PHYS.COND.CM-DS-NN] Physics [physics]/Condensed Matter [cond-mat]/Disordered Systems and Neural Networks [cond-mat.dis-nn], [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, [CHIM.THEO] Chemical Sciences/Theoretical and/or physical chemistry, 6250-p, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], numbers: 6145Fs, [PHYS.COND.CM-DS-NN]Physics [physics]/Condensed Matter [cond-mat]/Disordered Systems and Neural Networks [cond-mat.dis-nn], [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], [PHYS.COND] Physics [physics]/Condensed Matter [cond-mat]
Abstract: International audience; The structural properties of glassy diboron trioxide, g-B2O3 , are investigated from ambient to high pressure conditions using two types of atomic force-field models that account for many-body effects. These models are parameterized by a dipole-and force-fitting procedure of reference data sets created via first-principles calculations on a series of configurations. The predictions of the models are tested against experimental data, where particular attention is paid to the structural transitions in g-B2O3 that involve changes to both the short-and medium-range order. The models outperform those previously devised, where improvement originates from the incorporation of two key physical ingredients , namely (i) the polarizability of the oxide ion and (ii) the ability of an oxide ion to change both size and shape in response to its coordination environment. The results highlight the importance of many-body effects for accurately modelling this challenging system.
Published: 2019

45. ToF-SIMS depth profiling of altered glass

Author: Patrick Jollivet, Laurent Duffours, Marie Collin, Laurent Dupuy, Vincent Dauvois, Stéphane Gin, Département de recherche sur les Procédés et Matériaux pour les Environnements complexes (DPME), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Laboratoire d'Etudes du Comportement à Long Terme des matériaux de conditionnement (LCLT), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Tescan Analytics, Laboratoire de Radiolyse et de la Matière Organique (LRMO), Service d'Etudes du Comportement des Radionucléides (SECR), Département de Physico-Chimie (DPC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Département de Physico-Chimie (DPC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, PrimeVerre, and Département de recherche sur les technologies pour l'enrichissement, le démantèlement et les déchets (DE2D)
Subjects: Chemical process, Potential impact, Materials science, Ion beam, Materials Science (miscellaneous), Analytical chemistry, 02 engineering and technology, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, Silicate, 0104 chemical sciences, Corrosion, Secondary ion mass spectrometry, chemistry.chemical_compound, chemistry, Chemistry (miscellaneous), Materials Chemistry, Ceramics and Composites, lcsh:TA401-492, Glass corrosion, lcsh:Materials of engineering and construction. Mechanics of materials, 0210 nano-technology, Beam (structure)
Abstract: Glass and mineral corrosion usually leads to the formation of morphologically and compositionally complex surface layers that can be characterized by various analytical techniques to infer rate control mechanisms. In this study, we investigate the capabilities and limitations of time-of-flight secondary ion mass spectrometry (ToF-SIMS) to better understand chemical processes of glass corrosion. In particular, we focus on the potential impact of the ToF-SIMS ion beam on the distribution of several elements of interest in alteration layers formed on International Simple Glass, a six-oxide reference glass altered in a solution enriched in alkalis and spiked with H218O. A thin flake of glass partially altered on both sides is analyzed entirely from one side to the other to determine whether atoms weakly bonded to the solid are displaced by the beams. We highlight the beam effect on cations weakly bonded to the silicate network (Li, Na, K, and B, Ca, Cs to a lesser extent) affecting the profile shape of these elements. No impact is observed on 18O and H, but it is demonstrated that quantification of isotopic ratios is possible only for a limited range of isotopic enrichment.
Published: 2019

46. Comparative effect of alkaline elements and calcium on alteration of International Simple Glass

Author: Emmanuelle Garcès, Nicole Godon, Hélène Aréna, Diane Rébiscoul, Nanomatériaux pour l'Energie et le Recyclage (LNER), Institut de Chimie Séparative de Marcoule (ICSM - UMR 5257), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Laboratoire d'Etudes du Comportement à Long Terme des matériaux de conditionnement (LCLT), Département de recherche sur les technologies pour l'enrichissement, le démantèlement et les déchets (DE2D), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), This work was funded by CEA, ORANO, and EDF., Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Département de recherche sur les Procédés et Matériaux pour les Environnements complexes (DPME), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)
Subjects: [PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th], Materials Science (miscellaneous), chemistry.chemical_element, 02 engineering and technology, Calcium, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, chemistry.chemical_compound, 0103 physical sciences, Materials Chemistry, lcsh:TA401-492, 010302 applied physics, SIMPLE (dark matter experiment), Chemistry, Limiting, 021001 nanoscience & nanotechnology, Nanopore, Calcium carbonate, Chemical engineering, Chemistry (miscellaneous), Ceramics and Composites, lcsh:Materials of engineering and construction. Mechanics of materials, Charge compensation, 0210 nano-technology, Transport phenomena, Layer (electronics)
Abstract: In the concept of deep geological repository for High Level Wastes, the chemical elements present in the media are expected to impact the long-term behavior of the glass. The effects of Ca, K, and Cs on International Simple Glass glass alteration are compared through long-term experiments (180–500 days). These elements limit glass alteration by their incorporation into the gel layer. The limiting mechanisms driving glass alteration appear to be mainly diffusive, at least during the first six months. The three cations are not equally efficient in limiting glass alteration: the effects of Ca are stronger than those of Cs and K. Multi-element experiments show that the effects of these elements are additive and proportional to the quantity of each element incorporated. When they play the role of charge compensator in the gel network, their incorporation is competitive and follows the order Ca ≫ Cs > K. In addition, when Ca is added to the solution in excess, the quantity of elements incorporated into the gel layer is higher than the amount required for charge compensation. The incorporation of Ca in the gel nanopores as calcium carbonate could explain this phenomenon. These processes could slow the transport phenomena through the gel and enhance its protective properties.
Published: 2019

47. Dynamics of self-reorganization explains passivation of silicate glasses

Author: Maxime Fournier, Sebastien N. Kerisit, Stéphane Gin, Jincheng Du, Laurent Dupuy, Patrick Jollivet, Marie Collin, Yves Minet, Thiruvilla S. Mahadevan, Département de recherche sur les technologies pour l'enrichissement, le démantèlement et les déchets (DE2D), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Laboratoire d'Etudes du Comportement à Long Terme des matériaux de conditionnement (LCLT), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Tescan Analytics, Department of Materials Science and Engineering, University of North Texas (UNT), Pacific Northwest National Laboratory (PNNL), and Département de recherche sur les Procédés et Matériaux pour les Environnements complexes (DPME)
Subjects: Materials science, Silicon, Passivation, Science, General Physics and Astronomy, chemistry.chemical_element, 02 engineering and technology, Thermal diffusivity, Molecular sieve, 01 natural sciences, Article, General Biochemistry, Genetics and Molecular Biology, [SPI.MAT]Engineering Sciences [physics]/Materials, 0103 physical sciences, Reactivity (chemistry), lcsh:Science, Dissolution, [PHYS]Physics [physics], 010302 applied physics, Multidisciplinary, Borosilicate glass, General Chemistry, 021001 nanoscience & nanotechnology, Amorphous solid, chemistry, 13. Climate action, Chemical physics, lcsh:Q, 0210 nano-technology
Abstract: Understanding the dissolution of silicate glasses and minerals from atomic to macroscopic levels is a challenge with major implications in geoscience and industry. One of the main uncertainties limiting the development of predictive models lies in the formation of an amorphous surface layer––called gel––that can in some circumstances control the reactivity of the buried interface. Here, we report experimental and simulation results deciphering the mechanisms by which the gel becomes passivating. The study conducted on a six-oxide borosilicate glass shows that gel reorganization involving high exchange rate of oxygen and low exchange rate of silicon is the key mechanism accounting for extremely low apparent water diffusivity (∼10−21 m2 s−1), which could be rate-limiting for the overall reaction. These findings could be used to improve kinetic models, and inspire the development of new molecular sieve materials with tailored properties as well as highly durable glass for application in extreme environments., Deciphering the dissolution process of silicate glasses and minerals from atomic to macroscopic scales is a major challenge. Here, the authors explain the passivating properties of the gel layer by its reorganization, which is a key mechanism accounting for very low apparent water diffusivity.
Published: 2018

48. Impact of alkali on the passivation of silicate glass

Author: Mélanie Moskura, Thibault Charpentier, Maxime Fournier, Marie Collin, Stéphane Gin, Département de recherche sur les technologies pour l'enrichissement, le démantèlement et les déchets (DE2D), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Laboratoire Structure et Dynamique par Résonance Magnétique (LCF) (LSDRM), Nanosciences et Innovation pour les Matériaux, la Biomédecine et l'Energie (ex SIS2M) (NIMBE UMR 3685), Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), This work was supported as part of the Center for Performance and Design of Nuclear Waste Forms and Containers, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Basic Energy Sciences under Award # DESC0016584., Département de recherche sur les Procédés et Matériaux pour les Environnements complexes (DPME), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Rayonnement Matière de Saclay (IRAMIS), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Aqueous solution, Passivation, Borosilicate glass, Chemistry, Materials Science (miscellaneous), Inorganic chemistry, Ionic bonding, 02 engineering and technology, [CHIM.MATE]Chemical Sciences/Material chemistry, 010402 general chemistry, 021001 nanoscience & nanotechnology, Alkali metal, 01 natural sciences, 0104 chemical sciences, Amorphous solid, Ion, 13. Climate action, Chemistry (miscellaneous), Ionic strength, Materials Chemistry, Ceramics and Composites, lcsh:TA401-492, lcsh:Materials of engineering and construction. Mechanics of materials, 0210 nano-technology
Abstract: Amorphous silica-rich surface layers, also called gels, can passivate silicate glass and minerals depending on environmental conditions. However, several uncertainties remain on the mechanisms controlling the formation of these layers. In this paper, the influence of exogenous ions supplied by solutions is studied, both on the formation and on the properties of the gel formed on international simple glass (ISG). ISG was altered at 90 °C, pH90 °C 7, in silica-saturated solutions containing various alkaline cations separately (Li+, Na+, K+, and Cs+). The alteration kinetics observed with Li and Na in the solution is similar to that observed with no ions, while K and Cs in the solution tend to decrease glass alteration. Furthermore, for K or Cs ions, the kinetics decreases as the ionic strength of the solution increases. The passivation layer formed in these solutions shows a selectivity toward cations following the series K > Cs > Na >> Li. These alkalis replace Ca from pristine glass in the altered structures, leading to differences in [AlO4]− units charge compensation. Importantly, exchange between Ca and alkali also affects the total quantity of water inside each gel and this effect is well correlated with the observed drop in glass alteration. The presence of ions has been observed to affect the speed at which aqueous solutions alter the surface of a glass of nuclear interest. Borosilicate glasses are used to store highly radioactive waste in deep geological repositories, however, they are expected eventually to come into contact with ground water. Therefore, how they change when exposed to aqueous environments must be understood. Now, a team, led by Stephane Gin at the CEA, France, has studied the effects that various ionic solutions have on the formation and properties of the passivating silica-rich layers that can form on the surface of a reference glass known as International Simple Glass. They see that K+ and Cs+ ions decrease glass alteration kinetics, while the kinetics observed with Li+ and Na+ present are similar to solutions with no ions.
Published: 2018

49. Chemical durability of peraluminous glasses for nuclear waste conditioning

Author: Maxime Fournier, Patrick Jollivet, Stéphane Gin, I. Bardez-Giboire, V. Montouillout, Victor Piovesan, Nadia Pellerin, Pierre Frugier, Département de recherche sur les technologies pour l'enrichissement, le démantèlement et les déchets (DE2D), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Conditions Extrêmes et Matériaux : Haute Température et Irradiation (CEMHTI), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université d'Orléans (UO), AREVA, Groupe AREVA, Département de recherche sur les Procédés et Matériaux pour les Environnements complexes (DPME), and Université d'Orléans (UO)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 010302 applied physics, Aqueous solution, Materials science, Borosilicate glass, Precipitation (chemistry), Materials Science (miscellaneous), Alkalinity, Radioactive waste, 02 engineering and technology, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, Durability, 6. Clean water, Chemical engineering, 13. Climate action, Chemistry (miscellaneous), 0103 physical sciences, Materials Chemistry, Ceramics and Composites, lcsh:TA401-492, Thermal stability, lcsh:Materials of engineering and construction. Mechanics of materials, 0210 nano-technology, Dissolution
Abstract: For the handling of high level nuclear waste (HLW), new glass formulations with a high waste capacity and an enhanced thermal stability, chemical durability, and processability are under consideration. This study focuses on the durability of peraluminous glasses in the SiO2–Al2O3–B2O3–Na2O–CaO–La2O3 system, defined by an excess of Al3+ ions compared with the network-modifying cations Na+ and Ca2+. To qualify the behavior of such a peraluminous glass in a geological storage situation, its chemical durability was studied in various environments (pure water, groundwater, and alkaline solutions related to a cement environment) and glass alteration regimes (initial rate, residual rate, and resumption of alteration). The alteration solution was characterized by inductively coupled plasma, and the altered glass by scanning electron microscopy, X-ray diffraction and secondary ion mass spectrometry. A comparative study of the chemical durability of these and reference glasses (ISG and SON68) over all timescales highlights the remarkable properties of the former. While their initial dissolution rate is of the same order as the reference glasses, the gel formed under silica saturation conditions is more passivating, making its dissolution rate at least one order of magnitude lower, while its low alkalinity makes it less susceptible to clayey groundwater and highly alkaline solutions. How a ‘peraluminous’ glass—of interest in nuclear waste storage—changes in solution has been studied. The long term behaviour of borosilicate nuclear glasses, used to store high-level nuclear waste, has important safety ramifications and it is known that dissolution and precipitation processes in water can affect their durability. A team, led by Maxime Fournier at the CEA, Marcoule, France, has now studied the durability of a ‘peraluminous’ glass, which is defined by its excess of Al3+ ions as compared to more standard ‘peralkaline’ glasses. Such materials are known to form passivating layers on their surface in aqueous solution and the researchers observe that the layer that forms on the surface of the ‘peraluminous’ glass is more passivating than that on the peralkaline reference glasses used for comparison, resulting in a significantly lower dissolution rate.
Published: 2018

50. Treatment of radioactive liquid effluents by reverse osmosis membranes: From lab-scale to pilot-scale

Author: Luc Schrive, Yvan Wyart, Emilie Carretier, Véronique Labed, Philippe Moulin, Nicolas Combernoux, CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Laboratoire de Mécanique, Modélisation et Procédés Propres (M2P2), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), MOULIN, Philippe, Service des Procedés de Décontamination et d'Enrobage des Déchets (SPDE), Centre National de la Recherche Scientifique (CNRS)-École Centrale de Marseille (ECM)-Aix Marseille Université (AMU), Département de recherche sur les technologies pour l'enrichissement, le démantèlement et les déchets (DE2D), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), and Département de recherche sur les Procédés et Matériaux pour les Environnements complexes (DPME)
Subjects: Osmosis, Environmental Engineering, [SPI.GPROC] Engineering Sciences [physics]/Chemical and Process Engineering, Gamma irradiation, 02 engineering and technology, 010501 environmental sciences, 01 natural sciences, 7. Clean energy, Permeability, Water Purification, Groundwater pollution, [SPI.GPROC]Engineering Sciences [physics]/Chemical and Process Engineering, Reverse osmosis, Waste Management and Disposal, ComputingMilieux_MISCELLANEOUS, Reverse osmosis membrane, Radionuclides, 0105 earth and related environmental sciences, Water Science and Technology, Civil and Structural Engineering, Chromatography, Fouling, Chemistry, Ecological Modeling, Radiochemistry, Decontamination process, Membranes, Artificial, Human decontamination, 021001 nanoscience & nanotechnology, Pollution, 6. Clean water, Membrane, 13. Climate action, Seawater, Water treatment, 0210 nano-technology, Filtration
Abstract: International audience; The recent use of the reverse osmosis (RO) process at the damaged Fukushima-Daiichi nuclear power plant generated a growing interest in the application of this process for decontamination purposes. This study focused on the development of a robust RO process for decontamination of two kinds of liquid effluents: a contaminated groundwater after a nuclear disaster and a contaminated seawater during a nuclear accident. The SW30 HR membrane was selected among other in this study due to higher retentions (96% for Cs and 98% for Sr) in a true groundwater. Significant fouling and scaling phenomenon, attributed to calcium and strontium precipitation, were evidenced in this work: this underscored the importance of the lab scale experiment in the process. Validation of the separation performances on trace radionuclides concentration was performed with similar retention around 96% between surrogates Cs (inactive) and 137Cs (radioactive). The scale up to a 2.6 m2 spiral wound membrane led to equivalent retentions (around 96% for Cs and 99% for Sr) but lower flux values: this underlined that the hydrodynamic parameters (flowrate/cross-flow velocity) should be optimized. This methodology was also applied on the reconstituted seawater effluent: retentions were slightly lower than for the groundwater and the same hydrodynamic effects were observed on the pilot scale. Then, ageing of the membrane through irradiation experiments were performed. Results showed that the membrane active layer composition influenced the membrane resistance towards γ irradiation: the SW30 HR membrane performances (retention and permeability) were better than the Osmonics SE at 1 MGy. Finally, to supplement the scale up approach, the irradiation of a spiral wound membrane revealed a limited effect on the permeability and retention. This indicated that irradiation conditions need to be controlled for a further development of the process.
Published: 2017

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