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Identification of Oxygen-Depleting Components in MX-80 Bentonite

Published online by Cambridge University Press:  01 February 2011

Torbjörn Carlsson
Affiliation:
[email protected], United States
Arto Muurinen
Affiliation:
[email protected], VTT Technical Research Centre of Finland, Espoo, Finland
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Abstract

After closure, the near-field of a nuclear waste repository contains large amounts of oxygen in tunnels and deposition holes. The bentonite buffer/backfill will contain oxygen as a gas phase in unsaturated pores as well as dissolved gas in porewater. The redox conditions in the bentonite filling after post-closure will change towards reducing conditions. In the initial stage, the development of the redox state is mainly governed by the depletion of oxygen. The main mechanisms of oxygen depletion in the bentonite are: 1) diffusion into the surrounding rock and 2) reactions with accessory minerals and by microbial aerobic consumption of organic matter [1,2]. The reactions leading to oxygen depletion are not, however, well understood. The objective of this work was to gather new information concerning oxygen depletion in MX-80. This was done by measuring oxygen depletion and changes in the redox state in suspensions of 1) MX-80, 2) a heavy fraction of MX-80, or 3) a light fraction of MX-80.

Type
Research Article
Copyright
Copyright © Materials Research Society 2009

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References

REFERENCES

1 Grandia, F., Domènech, C., Arcos, D., and Duro, L., SKB Report R-06–106 (2006).Google Scholar
2 Pastina, B. and Hellä, P., Posiva Report 2006–5 (2006).Google Scholar
3 Posiva, Oy, Safety Case Plan, Posiva Report 2008–05 (2008).Google Scholar
4 Danielson, M.J., Koski, O.H., and Myers, J. in Scientific Basis for Nuclear Waste Management VII, edited by McVay, G.L., (Mater. Res. Soc. Proc. 2, North-Holland, New York, 1984) pp.153160.Google Scholar
5. Lazo, C., Karnland, O., Tullborg, E.-L., and Puigdomenech, I. in Scientific Basis for Nuclear Waste Management XXVI, edited by Finch, R.J. and Bullen, D.B., (Mater. Res. Soc. Proc. 757, Warrendale, PA, 2003) pp. 643648.Google Scholar
6. Wersin, P., Spahiu, K., and Bruno, J., SKB Report TR-94–02 (1994).Google Scholar
7. Karnland, O., Olsson, S., and Nilsson, U., SKB Report TR-06–30 (2006).Google Scholar
8. Arcos, D., Grandia, F., Domènech, C., Fernández, A.M., Villar, M.V., Muurinen, A., Carlsson, T., Sellin, P., and Hernán, P., J. Contam. Hydrol. 102, 196209 (2008).Google Scholar
9. Yao, S., Wang, M. and Madou, M., J. Electrochem. Soc. 148(4), H29H36 (2001).Google Scholar
10. Muurinen, A. and Carlsson, T., Phys. Chem. Earth 32, 241246 (2007).Google Scholar
11. Masurat, P., Eriksson, S., and Pedersen, K., Appl. Clay Sci. (2008) doi:10.1016/j.clay.2008.07.002Google Scholar