Hostname: page-component-78c5997874-ndw9j Total loading time: 0 Render date: 2024-11-14T17:48:40.406Z Has data issue: false hasContentIssue false
  • English
  • Français

Assessment of Redox Conditions in the Near Field of Nuclear Waste Repositories: Application to the Swiss high-level and intermediate level waste disposal concept

Published online by Cambridge University Press:  01 February 2011

Paul Wersin ,
Lawrence H. Johnson  and
Bernhard Schwyn
Paul Wersin
Affiliation:
National Cooperative for the Disposal of Radioactive Waste (Nagra), 5430 Wettingen, Switzerland
Lawrence H. Johnson
Affiliation:
National Cooperative for the Disposal of Radioactive Waste (Nagra), 5430 Wettingen, Switzerland
Bernhard Schwyn
Affiliation:
National Cooperative for the Disposal of Radioactive Waste (Nagra), 5430 Wettingen, Switzerland
Get access

Abstract

Redox conditions were assessed for a spent fuel and high-level waste (SF/HLW) and an intermediate-level waste (ILW) repository. For both cases our analysis indicates permanently reducing conditions after a relatively short oxic period. The canister-bentonite near field in the HLW case displays a high redox buffering capacity because of expected high activity of dissolved and surface-bound Fe(II). This is contrary to the cementitious near field in the ILW case where concentrations of dissolved reduced species are low and redox reactions occur primarily via solid phase transformation processes.

For the bentonite-canister near field, redox potentials of about -100 to -300 mV (SHE) are estimated, which is supported by recent kinetic data on U, Tc and Se interaction with reduced iron systems. For the cementitious near field, redox potentials of about -200 to -800 mV are estimated, which reflects the large uncertainties related to this alkaline environment.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 807: Symposium Scientific Basis for Nuclear Waste Management XXVII , 2003 , 539
Copyright
Copyright © Materials Research Society 2004

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. Nagra, , Nagra Technical Report 02–05, Switzerland (2003).Google Scholar
2. Wersin, P., Johnson, L.H., Schwyn, B., Berner, U., and Curti, E., Nagra Technical Report 02–13, Switzerland (2003).Google Scholar
3. Kreis, P., Nagra Technical Report 91–21, Switzerland (1991).Google Scholar
4. Ishikawa, T., Kondo, Y., Yasukawa, A., and Kandon, K., Corros. Sci. 40, 1239–1251 (1998).Google Scholar
5. Pearson, J. F., Nagra Technical Report, in press (2003).Google Scholar
6. Cui, D. and Spahiu, K., Radiochim. Acta 90, 623–628 (2003).Google Scholar
7. Johnson, L.H. and Smith, P.A., Nagra Technical Report 00–04, Switzerland (2000).Google Scholar
8. Pedersen, K., Motamedi, M., Karnland, O., and Sandén, T., J. Appl. Microbiol. 89, 1038–1047 (2000).Google Scholar
9. Jobe, D.L., Lemire, R.J. and Taylor, P., AECL report 11667, AECL, Canada (1997).Google Scholar
10. Curti, E. and Wersin, P., Nagra Technical Report 02–09, Switzerland (2002).Google Scholar
11. Hummel, W., Berner, U., Curti, E., Pearson, J.F., and Thoenen, T., Nagra Technical Report 02–16, Switzerland (2002).Google Scholar
12. Grauer, R., Nagra Technical Report 88–02E, Switzerland (1988).Google Scholar
13. Sarott, F.-A., Spieler, P., and Pandolfo, P., unpublished PSI report, Paul Scherrer Institute, Switzerland (1995).Google Scholar
14. Cui, D. and Eriksen, T., SKB Technical Report 96–03, Sweden (1996).Google Scholar
15. Myneni, S.C.B., Tokunaga, T.K., and Brown, G.E., Science 278, 1106–1109 (1997).Google Scholar
16. Scheidegger, A., Grolimund, D., Cui, D., Devoi, J., Bonhoure, I., Janosch, M., Wersin, P., K., , and de, Spahiu J. Physique IV, in press (2003).Google Scholar