Hostname: page-component-5c6d5d7d68-thh2z Total loading time: 0 Render date: 2024-08-11T12:22:41.862Z Has data issue: false hasContentIssue false

Dissolution of R7T7 Glass in Static and Flowing Conditions: Influence of Si Diffusion Mechanism in the Leached Layer

Published online by Cambridge University Press:  01 January 1992

F. Delage
Affiliation:
CEA CEN-VALRHO, SCD/SDMC, BP 171, F-30207 Bagnols-sur-Cèze, France
F. Larche
Affiliation:
Université de Montpellier Il GDPC, F-34090 Montpellier, France
E. Vernaz
Affiliation:
CEA CEN-VALRHO, SCD/SDMC, BP 171, F-30207 Bagnols-sur-Cèze, France
Get access

Abstract

Leach tests with R7T7 nuclear waste glass in distilled water were conducted at 50 and 90°C under static and slow flowing conditions, with an SA/V ratio of 50 m−1. A computer model for glass dissolution (LIXIVER) Was used to interpret the experimental data. This mechanistic model is based on a combination of the first-order law governing surface reactions, the silicon mass transport equation for the interstitial solution in the alteration film, and an empirical law for partial silicon retention in the alteration layer. The LIXIVER model satisfactorily accounts for most of the experimental results. The importance of the silicon diffusion mechanism in the diffusion layer is stressed. Values are indicated for the apparent silicon diffusion coefficient, Dsi, which ranged from 10−16 to 10−14 m2·s−1 at 50°C, and from 10−15 to 10−13 m2·s−1 at 90°C.

Type
Research Article
Copyright
Copyright © Materials Research Society 1993

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1. Grambow, B., in Scientific Basis for Nuclear Waste Management VIII, edited by Jantzen, C.M., Stone, A. and Ewing, R.C., (Mater. Res. Soc. Proc. 44, Pittsburgh, PA, 1985) pp. 1522.Google Scholar
2. Grambow, B., Hermansson, H.P., Bjtirner, I.K., Christensen, H. and Werme, L., in Advances in Ceramics 20, Nuclear Waste Management III, edited by Mellinter, B. (1989) pp. 465473.Google Scholar
3. Delage, F., Ghaleb, D., Dussossoy, J.L., Chevallier, O. and Vernaz, E., Journ. Nucl. Mat special issue (to be published in 1992).Google Scholar
4. Mouche, E. and Vernaz, E., in Scientific Basis for Nuclear Waste Management XI, (Mater. Res. Soc. Proc. 112, Pittsburgh, PA, 1988) pp. 703712.Google Scholar
5. Barkatt, A.A., Gibson, B.C. and Brandis, M., in Scientific Basis for Nuclear Waste Management VIII, edited by Jantzen, C.M., Stone, A. and Ewing, R.C., (Mater. Res. Soc. Proc. 44, Pittsburgh, PA, 1985) pp. 229235.Google Scholar
6. Fillet, S., PhD Thesis, University of Montpellier, France (1986).Google Scholar
7. Delage, F., PhD Thesis, University of Montpellier, France (1992).Google Scholar
8. Fritz, B., Sci. Géol. Mérm. 65, PhD thesis, University of Strasbourg, 1981.Google Scholar