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Durabilité chimique et comportement à l'irradiation des verres quaternaires LnYSiAlO (Ln = La ou Ce)

Abstract : such, they have the potential to be used in the nuclear industry for the specific immobilization of trivalent actinides. Initial dissolution rates of LaYSiAlO and CeYSiAlO were determined using a Soxhlet device (dynamic leaching). The differences linked to the nature of the rare earth element were studied by synthesizing analogous glasses that only differed in their rare earth element composition (%at.) : Y-5%, La-5 %, Si-15%, Al-10% O-65%. The influence of pH on the dissolution mechanisms and kinetics was also studied by static leaching tests performed in dilute solutions of NaOH or HNO3. Electronic defects and collision cascades, induced by a-disintegration of radioelements confined in storage matrice, can cause important modifications in the glass structure and, thus, influence its chemical durability. To simulate these effects, glass samples were irradiated with b particles and heavy ions accelerated to 2,5 MeV and 200 keV, respectively. Monoliths were then leached in static bidistilled water (pH » 5.5) for one month in an autoclave heated to 90°C. Initially, the structural changes caused by irradiation were determined using Raman, NMR and EPR spectroscopies. Ion µbeams, SEM-EDS and XPS analysis were also performed to evaluate the potential modifications of the superficial composition. Finally, the leaching behavior was studied, for both irradiated and unirradiated samples, through solution and solid elementary characterization.
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https://tel.archives-ouvertes.fr/tel-00002852
Contributor : Stéphane Gavarini <>
Submitted on : Wednesday, May 21, 2003 - 10:17:14 AM
Last modification on : Thursday, February 1, 2018 - 1:38:29 AM
Long-term archiving on: : Friday, April 2, 2010 - 6:42:36 PM

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  • HAL Id : tel-00002852, version 1

Citation

Stéphane Gavarini. Durabilité chimique et comportement à l'irradiation des verres quaternaires LnYSiAlO (Ln = La ou Ce). Autre. Université d'Orléans, 2002. Français. ⟨tel-00002852⟩

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