Hostname: page-component-8448b6f56d-tj2md Total loading time: 0 Render date: 2024-04-19T00:53:47.662Z Has data issue: false hasContentIssue false
  • English
  • Français

Geogas in Crystalline Bedrock and its Potential Significance for Disposal of Nuclear Waste

Published online by Cambridge University Press:  15 February 2011

Rolf SjÖblom ,
Hans-Peter Hermansson  and
Gustav Åkerblom
Rolf SjÖblom
Affiliation:
Swedish Nuclear Power Inspectorate, Box 27 106, S–102 52 Stockholm, Sweden
Hans-Peter Hermansson
Affiliation:
Studsvik Material AB, S–611 82 Nyköping, Sweden
Gustav Åkerblom
Affiliation:
Swedish Radiation Protection Institute, Box 60 204, S–104 01 Stockholm, Sweden
Get access

Abstract

In assessments of the safety of final repositories for nuclear waste situated in crystalline basement rock it is usually postulated that the transfer of radionuclides to the biosphere can take place only through transport by water. However, in order for such an assumption to be valid, it must be verified that any geogas that is present will not affect the transport - at least not to any significant degree. (The word geogas refers to the occurrence in the crystalline basement rock of substances which become gaseous at normal pressures and temperatures.)

Geogas in crystalline rock consists of species such as nitrogen, argon, helium, hydrogen, methane, carbon monoxide, carbon dioxide, hydrogen sulfide, and oxygen. The gas originates from the atmosphere, chemical reactions in the rock, the decay of radioactive elements in the rock, and degassing from the mantle of the earth. In most observed cases, geogas is dissolved in the groundwater. However, at elevated pressures and at low temperatures, methane may combine with water to form a solid phase commonly called methane-ice.

The transfer of geogas through the rock and to the surface takes place through flow in fractures. Firstly, dissolved geogas migrates due to the flow of the groundwater, and secondly, pockets of gas may form and eventually be released in the form of bursts. In the second case, the gas might act as a carrier for heavy elements through four different mechanisms: 1) formation of volatile compounds, 2) formation of surface active complexes, 3) flotation, and 4) formation of aerosols.

When a potential site for waste disposal is being evaluated, studies of geogas should form part of such a characterization programme. Favourable conditions for the formation of free gas may develop as a result of the heating of the rock by radioactive decay in the waste. It is also conceivable that methane-ice might form in the backfill of a repository in connection with a glaciation. The decomposition behaviour of such methane-ice appears to be largely unknown. Positive aspects may include the possibility of utilizing geogas flow for the non-destructive monitoring of a site after closure of the repository.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 353: Symposium – Scientific Basis for Nuclear Waste Management XVIII , 1994 , 477
Copyright
Copyright © Materials Research Society 1995

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. Hermansson, H-P, Åkerblom, G., Chyssler, J., , J. and Lindén, A.. Geogas - a carrier or a tracer? SKN Report 51, Stockholm, October 1991.Google Scholar
2. Hermansson, H-P, Sjöblom, R., and Åkerblom, G.. Geogas in crystalline bedrock. SKN Report 52, Stockholm,October 1991.Google Scholar
3. Low, J. and Hermansson, H-P. Methane-ice, a literature survey, SKN Arbets-PM 1991:1, Stockholm, April 1991. In Swedish.Google Scholar
4. Pederson, K.. The deep subterranean biosphere. Earth-science reviews, 34, 243–260. Elsevier Science Publishers B.V., Amsterdam 1993.Google Scholar
5. Molecular form of elements: evaluation of a new atmogeochemical method. Bergsmanna-föreningen 1990, ISBN 951–95365–4–X, Finland. In Finnish.Google Scholar
6. Juhlin, C., Castanño, J., Collini, B., Corody, T., Sandstedt, H., and Adin Aldahan, Ala. Scientific summary report of deep gas drilling project in the Siljan Ring impact structure. Vattenfall Research and Development, Stockholm, 1991.Google Scholar
7. Wikberg, P.. The Swedish Nuclear Fuel and Waste Management Company. Private communication.Google Scholar
8. Kvenvolden, K.A.. Methane hydrate. A major reservoir of carbon in the shallow geosphere? Chem. Geol. 71, 441–51, 1988.Google Scholar
9. Shipley, T.H., and Didyk, B.M.. Occurrence of methane hydrates offshore southern Mexico. Initial Rep Deep Sea Drill Proj, Vol 66, 547–55, 1982.Google Scholar
10. Makogon, Y.F., and Morozov, I.F.. Methane hydrate and explosivity of coal seams. Bezop Tr Prom-sti, 17(12), 26–7, 1973.Google Scholar
11. Van der Vaals, J.H. and Platteev, J.C.C.. Adv Chem Phys 2, 1, 1959.Google Scholar
12. Makagon, Y.F. et al. Detection of a pool of natural gas in a solid (hydrated gas) state. Dokl Acad Nauk SSSR 196, 203, 1971.Google Scholar
13. Burshears, M. and Dominic, K.. Gas hydrate model development and validation. Energy Res Abstr, 13(7) Abstr No 14125, 1988.Google Scholar
14. Sloan, E.D.. Phase equilibria of natural gas hydrates. Proc. Annu Conv - Gas Process Assoc, 63rd, (163–9), 1984.Google Scholar
15. Söderberg, P. and Flodén, T.. Geophysical and geochemical investigations related to tectonic lineamants in the archipelago of Stockholm - investigations at Vettershaga and Stavnas, 1984 – 1988. The Swedish State Power Board, Utveckling och Miljö, U(G) 1989/20, 1989–01–11. In Swedish.Google Scholar
16. Söderberg, P.. Seismic stratigraphy, tectonics and gas migration in the Äland Sea, Northern Baltic Proper. Stockholm Contributions in Geology 43, part 1, 1993. Stockholm University, Department of Geology and Geochemistry. Doctoral thesis.Google Scholar
17. Kristiansson, K. and Malmqvist, L.. Trace elements in the geogas and their relation to bedrock composition. Gasexploration 24, 517–534, 1987.Google Scholar
18. Kristiansson, K. and Malmqvist, L.. The funnel reveals what has been hidden in the ground. Teknik i tiden 2, 12–13, 1989. In Swedish.Google Scholar
19. Johansson, S.A.E. and Johansson, T.B., T.B. Analytical application of particle induced X-ray emission. Nucl. Instr. Meth 137, 473–516, 1976.Google Scholar
20. Stephanson, O.. Royal Institute of Technology in Stockholm. Private communication.Google Scholar
21. Alberty, R.A.. Physical Chemistry. John Wiley & Sons, 1987.Google Scholar
22. Elschenbroich, C.H. and Organometallics, Salzer., a Concise Introduction. VCH 1989, ISBN 3–527–27817–6 (originally published in German: Organometallchemie - Eine kurze Einfürung).Google Scholar
23. Kirk-Othmer, et al. Carbonyls. Encyclopedia of Chemical Technology, 2nd edition, Vol 4, p 489–510, John Wiley & Sons Inc, 1964.Google Scholar
24. Sax, N.I. and Lewis, R.J.. Dangerous Properties of Industrial Materials. Van Nostrand Reinhold, 1989.Google Scholar
25. Walker, M.I. et al. Actinide enrichment in marine aerosols. Nature 323, 141–143, 1986.Google Scholar
26. Perry, R.H. et al. Flotation. Perry’s Chemical Engineers’ Handbook, 6th edition, p 21–46—21–53, McGraw-Hill Book Company, 1984.Google Scholar
27. Henderson, P.. Inorganic Geochemistry. Pergamon Press, 1986, ISBN 0–08–020448–1.Google Scholar
28. The SKI performance assessment project SITE 94. Main report. SKI Report, in preparation.Google Scholar
29. Björklund, A.. Methane venting as a possible mechanism for glacial plucking and fragmentation of precambrian crystalline bedrock. GFF (Geologiska Föreningens i Stockholm Forhandlingar), 112(4), p 329–331, Stockholm, 1990. ISSN, 0016–786X.Google Scholar