Skip to main content Accessibility help
×
Home

SR 97: Spent Fuel Alteration/Dissolution and the Influence of Near Field Hydrogen

  • Kastriot Spahiu (a1) and Patrik Sellin (a1)

Abstract

A discussion of the evaluation of the source term in the SR 97 safety assessment of a deep repository for spent nuclear fuel is presented. Since the majority of the radionuclides are embedded in the uranium dioxide fuel matrix, they will be released only after the alteration/dissolution of the matrix. Therefore a description of the process of alteration/dissolution of the spent fuel matrix is needed in a safety assessment.

Under normal repository conditions, i.e. reducing environment and neutral to alkaline pH, uranium dioxide has a very low solubility in water. If solubility is assumed to be the limiting factor, the dissolution of the fuel matrix will proceed very slowly due to the low water exchange in the defective canister. On this basis, a solubility-limited model for the release of the radionuclides from the fuel may be formulated.

The reducing conditions can be upset by the radioactivity of the spent fuel, which generates oxidizing products through water radiolysis. This causes the oxidative alteration/dissolution of the UO2(s) matrix. A model for fuel matrix conversion resulting from radiolytic oxidative dissolution is discussed, as well as parameter variations and the associated uncertainties.

In a repository the spent fuel will come in contact with groundwater after the copper canister has breached. Large amounts of hydrogen are then produced through the anoxic corrosion of the cast iron insert. Recent data on spent fuel leaching in presence of repository relevant hydrogen pressures and the implications on the actual and future spent fuel dissolution modeling will also be discussed.

Copyright

References

Hide All
1.Final Storage of Spent Nuclear Fuel - KBS-3. Swedish Nuclear Fuel Supply Co/Division KBS, Stockholm 1983.
2.Deep repository for spent nuclear fuel. SR 97 - Post-closure safety, SKB TR 99-06, Stockholm 1999.
3. Sellin, P., SR 97: Hydromechanical evolution in a defective canister, this volume.
4. Kleykamp, H., Nuclear Technology, 80, 412 (1988)
5. Johnson, L., Tait, J., SKB Technical Report 97-18, Stockholm 1997.
6. Bruno, J., Cera, E., Pablo, J. De, Duro, L., Jordana, S., Savage, D., SKB Technical Report 97-33, Stockholm 1997
7. Wersin, P., Spahiu, K. and Bruno, J., SKB Technical Report 94-02, Stockholm 1994.
8. , Puigdomenech, Banwart, S., Bateman, K., Milodowski, A., West, J., Grifault, L., Gustafsson, E., Hama, K., Yoshida, H., Kotelnikova, S., Pedersen, K., Lartigue, J-E., Michaud, V., Trotignon, L., Morosini, M., Rivas, J., Tullborg, E-L., SKB International Cooperation Report 99-01, Stockholm 1999.
9. Werme, L., Sellin, P., Forsyth, R., SKB Technical Report 90-08, Stockholm 1990.
10. Garrels, R. M and Christ, C. L, Solutions, Minerals, and Equilibria, Harper & Row, New York 1965, 450 p.
11. Ageskog, L., Jansson, P., SKB Technical Report 99-02, Stockholm 1999.
12. Vieno, T., Hautojärvi, A., Koskinen, L., Nordman, H., TVO-92 Safety analysis of spent fuel disposal, YJT 92-33, Technical Research Centre of Finland, 1992.
13. Vieno, T., Nordman, H., TILA-99. Posiva 99-07, Posiva Oy, Helsinki 1999.
14. SKI SITE-94, SKI Report 96-36, Stockholm, 1994.
15. Eriksen, T., SKB Progress Report U-96-29, Stockholm 1996.
16. Ross, B. et al., NDRL-NIST Solution Kinetics Database, 1992.
17. Draganic, Z. D. et al. Radiat. Phys. Chem., 38, 317 (1991).
18. Torrero, M., Ph.D. Thesis, Universidad Politecnica de Catalunya, Barcelona 1995.
19. Gimenez, L, Ph.D. Thesis, Universidad Politecnica de Catalunya, Barcelona 1996.
20. Shoesmith, D., Sunder, S., J. Nucl. Mater. 190, 20, (1992)
21. Carver, M., Hanley, D., Chaplin, K., AECL Report 6413, Canada, 1979.
22. Spahiu, K., Werme, L., Eklund, U.B., Radiochimica Acta (2000) in print.
23. Bruno, J., Cera, E., Eklund, U-B, Eriksen, T., Grive, M., SKB Technical Report 99-26, 1999.
24. Kelm, M., The formation of oxidants in NaCl Brines, Spent Fuel Workshop, Toronto, Canada 1999
25. Christensen, H., Nuclear Technology, 165, 124 (1998).
26. Colmenares, A., Prog. Solid State Chem., 15, 257 (1984)
27. Hedhilil, M. N., Yakshinskiy, B. V., Madey, T. E., Surface Science, 445, 512 (2000).
28. , Bunji, Zogovic, B., In: Proceedings of the International Symposium on Peaceful Uses of Atomic Energy, pp. 350355, Stockholm 1958.
29. Baker, M. McD., Less, L. N., and Orman, S., Trans. Faraday Soc., 62, 2525 (1966).
30. Haschke, J. M., Allen, T. H., Stakebake, J. L., J. Alloys and Compounds, 243, 23 (1996).
31. King, F., Quinn, M. J., Miller, N. H., SKB Technical Report 99-27, Stockholm 1999.

Related content

Powered by UNSILO

SR 97: Spent Fuel Alteration/Dissolution and the Influence of Near Field Hydrogen

  • Kastriot Spahiu (a1) and Patrik Sellin (a1)

Metrics

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed.