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Diffusion of Sodium and Copper in Compacted Sodium Bentonite at Room Temperature

Published online by Cambridge University Press:  21 February 2011

Arto Muurinen ,
Markus Olin  and
Kari Uusheimo
Arto Muurinen
Affiliation:
Technical Research Centre of Finland, Reactor Laboratory, Otakaari 3 A, SF-02150 ESPOO, FINLAND
Markus Olin
Affiliation:
Technical Research Centre of Finland, Reactor Laboratory, Otakaari 3 A, SF-02150 ESPOO, FINLAND
Kari Uusheimo
Affiliation:
Technical Research Centre of Finland, Reactor Laboratory, Otakaari 3 A, SF-02150 ESPOO, FINLAND
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Abstract

Diffusion studies were carried out with sodium and copper in sodium bentonite. The experiments were performed at room temperature and densities of the samples varied from 0.8 to 1.8 g/cm3.

This paper describes the experimental methods used for the diffusion tests and gives the obtained measurement results. The evaluation of the diffusion mechanisms is at this stage preliminary, however.

Diffusion of sodium seems to follow similar mechanisms as has been observed for cesium and strontium in several previous studies. The phenomena could be explained by some kind of diffusion of sorbed ions. The measured apparent diffusivities of sodium varied from 50×10−12 to 300×10−12 m2/s and the effective diffusivities from 80×10−12 to 1.6×10−9 m2/s depending on the density of bentonite and the salt concentration of water solution.

Low solubility of copper caused precipitation thus interfering the diffusion experiments. However, the part of copper which did diffuse into bentonite seemed to follow the same type of mechanism as sodium. The measured apparent diffusivities of copper varied from 5×10−12 m2/s.

The interaction between the cations in the circulating solutions and the sodium ion in bentonite were essential in this study.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 176: Symposium U – Scientific Basis for Nuclear Waste Management XIII , 1989 , 641
Copyright
Copyright © Materials Research Society 1990

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References

REFERENCES

[1] Neretnieks, I., Diffusivities of some dissolved constituents in compacted wet bentonite clay -MX80 and the impact on radionuclide migration in the buffer. Stockholm 1982, SKBF/KBS, TR 82-27. 15 p.Google Scholar
[2] Muurinen, A., PenttilA-Hiltunen, P. and Rantanen, J. in Scientific basis for nuclear waste management X, edited by Bates, J.K. and Seefeldt, W.B., 1987, pp 803–812.Google Scholar
[3] Muurinen, A., PenttilA-Hiltunen, P. and Uusheimo, K. presented at the 1988 MRS International symposium on the Scientific Basis for Nuclear Waste Management XII, Berlin (West), Germany, 1988 (unpublished).Google Scholar
[4] Grauer, R., Bentonite as backfill material in the high-level waste repository: chemical aspects. Baden, Switzerland 1986. NAGRA, Technical report 86-12E. 130 p.Google Scholar
[5] Eriksen, T.E., Ion diffusion in compacted sodium and calcium bentonites. Stockholm 1982, SKBF/KBS, TR 81-12. 11 p.Google Scholar
[6] Torstenfelt, B., Allard, B., Andersson, K. Kipatsi, H., Eliasson, L., Olofsson, U. and Persson, H., Radionuclide diffusion and mobilities in compacted bentonite. Stockholm 1983, SKBF/KBS, TR 83-34. 23 p.Google Scholar
[7] Eriksen, T. and Jacobsson, A., Diffusion in clay - experimental techniques and theoretical models. Stockholm 1984, SKBF/KBS, TR 84-05. 31 p.Google Scholar
[8] Cheung, S.C.H. and Gray, M.N., presented at the 1988 MRS International symposium on the Scientific Basis for Nuclear Waste Management XII, Berlin (West), Germany, 1988 (unpublished).Google Scholar