Hostname: page-component-77c89778f8-sh8wx Total loading time: 0 Render date: 2024-07-17T02:42:51.982Z Has data issue: false hasContentIssue false
  • English
  • Français

Enhancement of the Glass Corrosion in the Presence of Clay Minerals: Testing Experimental Results with an Integrated Glass Dissolution Model

Published online by Cambridge University Press:  01 January 1992

Enzo Curti ,
N. Godon  and
E.Y. Vernaz
Enzo Curti
Affiliation:
Paul Scherrer Institut, Villigen and Wdirenlingen, 5232 Villigen PSI, Switzerland
N. Godon
Affiliation:
CEN-VALRHO, B.P. 171, 30205 Bagnols-sur-Cèze Cedex, France
E.Y. Vernaz
Affiliation:
CEN-VALRHO, B.P. 171, 30205 Bagnols-sur-Cèze Cedex, France
Get access

Abstract

Recent glass dissolution experiments, conducted at 90°C in the presence of potential backfill materials, indicate remarkably faster glass corrosion in the presence of clay, compared to tests where the glass is leached either alone or with alternative backfill materials. This effect correlates with the clay content in the backfill, and may be attributed to the removal of silica from solution. Sorption, or dissolution with reprecipitation of a silica-rich clay, have been proposed as possible mechanisms for the silica consumption.

The results of some experiments have been tested against a glass dissolution model, in which a widely used kinetic equation for glass corrosion is coupled with diffusive silica transport through a single porosity, linearly sorbing medium, which represents the backfilling. Because the glass corrosion rates imposed by the kinetic equation are inversely proportional to the silicic acid concentration of the leachant contacting the glass, the model predicts enhanced glass dissolution if silica is sorbed by the porous medium.

The experimental data proved to be consistent with the predicted enhancement of the glass dissolution. Moreover, the model-estimated distribution coefficients for silica sorption (Kd) fall within the range of values extracted from available literature data, thus supporting the hypothesis that the observed high corrosion rates are due to sorption of silica on the clay mineral surfaces.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 294: Symposium V – Scientific Basis for Nuclear Waste Management XVI , 1992 , 163
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. Grauer, R.. Glasses used in the solidification of high level radioactive waste: their behaviour in aqueous solutions. NTB 83-01 E, NAGRA, Baden, Switzerland, 1983.Google Scholar
2. Lutze, W., in Radioactive Waste Forms for the Future, edited by Lutze, W. and Ewing, R.C., (Elsevier Science Publishers B.V., Amsterdam, 1988) pp. 1–157.Google Scholar
3. Grambow, B., Hermansson, H.P., Bjoemer, I.K. and Werme, L., in Scientific Basis for Nuclear Waste Management /X, edited by Werme, L. (Mater. Res. Soc. Proc., 50, Pittsburgh PA, 1985) pp. 187–194.Google Scholar
4. Vernaz, E.Y. and Dussossoy, J.L., Applied Geochemistry, Suppl. Issue No. 1, pp. 13–22. (1992).Google Scholar
5. NAGRA, Projekt Gewaehr Report NGB 85-09, NAGRA, Baden, Switzerland (1985).Google Scholar
6. Curti, E., and Smith, P.A., in Scientific Basis for Nuclear Waste Management XIV (Mater. Res. Soc. Symp. Proc. 212, Pittsburgh, PA, 1991), pp. 31–39.Google Scholar
7. Godon, N., and Vernaz, E. (1990), in Scientific Basis for Nuclear Waste Management XIII (Mater. Res. Soc. Symp. Proc. 176, Pittsburgh, PA, 1990), pp. 319–326.Google Scholar
8. Godon, N., Vernaz, E., Thomassin, J.H. and Touray, J.C., in Scientific Basis for Nuclear Waste Management XII, edited by Lutze, W. and Ewing, R.C., (Mater. Res. Soc. Proc. 127, Pittsburgh, PA, 1989) pp. 97–104.Google Scholar
9. Yariv, S., and Cross, H., Geochemistry of Colloid Systems (Springer Verlag, Berlin, 1979) 450 p.Google Scholar
10. Advocat, T., Les méalcanismes de corrosion en phase aqueuse du verre nucéaire R7T7. Approche experimentale.Essai de mod~lisation thdrmodynamique et cinitique, Ph.D. Thesis, Université Louis Pasteur, Strasbourg, France (1991), 213 p.Google Scholar
11. Godon, N., Effet des matériaux d' environnement sur I' altiration du verre nucldaire R777, phD. thesis, Universitdé d' Orleans, France (1988), 365 p.Google Scholar
12. Grauer, R., Bentonit als Verfuellmaterial im Endlagerfuer hochaktiven Abfall: Chemische Aspekte. EIR-Report Nr. 576, Wurenlingen, Switzerland, 1986.Google Scholar
13. Davis, J.A. and Kent, D.B., in Mineral-Water interface geochemistry, edited by Hochella, M.F. and White, A.F. (Reviews in Mineralogy, 23, Washington D.C., 1990).Google Scholar
14. Siever, R., and Woodford, N., Geochim. Cosmochim. Acta 37, pp. 1851–1880, (1972).Google Scholar
15. Beckwith, R.S. and Reeve, R., Aust. J. Soil Res. 1, pp. 157–168, (1963).Google Scholar
16. Tan, K.H., Soil Sci. 134, pp. 300–307., (1982).Google Scholar