Hostname: page-component-586b7cd67f-vdxz6 Total loading time: 0 Render date: 2024-11-30T15:19:12.307Z Has data issue: false hasContentIssue false
  • English
  • Français

Use of bentonite for isolation of radioactive waste products

Published online by Cambridge University Press:  09 July 2018

R. Pusch
R. Pusch*
Affiliation:
Clay Technology AB and Lund University of Technology, Lund, Sweden
Get access Rights & Permissions [Opens in a new window]

Abstract

Sodium smectite clay, commercially available in the form of bentonite powder, serves as a very effective water flow barrier and cation exchanger. At bulk densities between 1·9 and 2·2 g/cm3 after water uptake to reach complete saturation, the hydraulic conductivity is of the order of 10−14 to 10−13 m/s. The swelling potential produces a tight contact with confining structures, which makes bentonite ideal as overpack of rock-deposited radioactive canisters and for borehole and shaft sealing. At bulk densities between 1·1 and 1·3 g/cm3, the hydraulic conductivity of smectite gels is still sufficiently low to make them useful as effective grouts for sealing rock fractures. The longevity in a granite environment is very significant and the ultimate transformation residue—hydrous mica (“illite”)—preserves some of the excellent sealing properties of smectites.

Type
Research Article
Information
Clay Minerals , Volume 27 , Issue 3 , September 1992 , pp. 353 - 361
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1992

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

Atabek, R., Lajudie, A., Lechelle, J. & Pusch, R. (1990) Pilot field experiment with canister-embedding clay under simulated repository conditions. Eng. Geologyy, 28, 291–302.Google Scholar
Bucher, F. & Muller-Vonmoos, M. (1989) Bentonite as a containment barrier for the disposal of highly radioactive wastes. Appl. Clay Sci., 4, 157–177.CrossRefGoogle Scholar
Börgesson, L. (1985) Water flow and swelling pressure in non-saturated bentonite-based clay barriers. Eng. Geology, 21, 229–237.Google Scholar
Börgesson, L. & Fredrikson, A. (1990) Rheological properties of Na-smectite gels used for rock sealing. Eng. Geology 28, 431–441.Google Scholar
Borgesson, L. & Pusch, R. (1991) Rock sealing in radwaste repositories using modern grouting methods and smectite clay. Proc. Int. Soc. Rock Mechanics, Aachen, 1, 63–66.Google Scholar
Guven, N. (1990) Longevity of bentonite as buffer material in a nuclear-waste repository. Eng. Geology, 28, 233–247.CrossRefGoogle Scholar
Muurinen, A. (1990) Diffusion of uranium in compacted sodium bentonite. Eng. Geology, 28, 359–367.CrossRefGoogle Scholar
Pusch, R. (1982) Mineral-water interactions and their influence on the physical behavior of highly compacted Na bentonite. Can. Geotech. J., 19, 381–387.Google Scholar
Pusch, R. (1985) Dense smectite clay used as overpack of deeply buried metal canisters with highly radioactive wastes. Proc. 11th Int. Conf. Soil Mech. Found. Eng., San Francisco, 3, 1221–1224.Google Scholar
Pusch, R. & Carlsson, T. (1985) The physical state of pore water of Na smectite used as barrier component. Eng. Geology, 21, 257–265.Google Scholar
Pusch, R. (1987) Permanent crystal lattice contraction—A primary mechanism in thermally induced alteration of Na bentonite. Proc. Materials Res. Soc. Sym., Boston, 84, 791–802.Google Scholar
Pusch, R. & Touret, O. (1988) Heat effects on soft Na bentonite clay gels. Geol. For. Stockholm Forhandlingar, 110, 183–190.Google Scholar
Pusch, R., Gray, M., Huertas, F., Jorda, M., Barbreau, A. & Andre-Jehan, R. (1989) Sealing of radioactive waste repositories in crystalline rock. Proc. NEA/CEC Workshop OECD/OCED, Paris,, 214–228.Google Scholar
Pusch, R., Hokmark, H. & Karnland, O. (1990) Microstructural impact on the conductivity of smectite buffer clays. Proc. 9th Int. Clay Conf. Strasbourg III, 127–137.Google Scholar