Hostname: page-component-78c5997874-lj6df Total loading time: 0 Render date: 2024-11-10T20:11:35.458Z Has data issue: false hasContentIssue false
  • English
  • Français

Long-term effects of an iron heater and Äspö groundwater on smectite clays: Chemical and hydromechanical results from the in situ alternative buffer material (ABM) test package 2

Published online by Cambridge University Press:  02 January 2018

Sirpa Kumpulainen ,
Leena Kiviranta  and
Petri Korkeakoski
Sirpa Kumpulainen*
Affiliation:
B+Tech Oy, Laulukuja 4, 00420 Helsinki, Finland
Leena Kiviranta
Affiliation:
B+Tech Oy, Laulukuja 4, 00420 Helsinki, Finland
Petri Korkeakoski
Affiliation:
Posiva Oy, Olkiluoto, 27160 Eurajoki, Finland
*
*E-mail: sirpa.kumpulainen@btech.fi
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Smectite-rich clays are to be used in nuclear repositories for sealing in the radioactive waste. As the radioactive decay produces heat it may affect the chemical, physical and hydromechanical properties of the clay components in the repository. An ‘alternative buffer material’ (ABM) experiment is a Svensk Kärnbränslehantering AB (SKB)-led in situ heating test placed in boreholes in the Äspö tunnel (Sweden). The 2nd ABM package was dismantled in April 2013, after 6.5 y of equilibration with Äspö groundwater and 5 y of heating. The objective was to investigate the long-term effects of the iron heater and Äspö groundwater on four of 31 compacted blocks made of MX-80, Deponit CaN and Friedland clays.

Compared to the starting materials, major changes in the exchangeable cation populations were observed. Within horizontal profiles, water-soluble sulfate, Ca, K and Mg increased; poorly crystalline Fe oxide contents decreased; total Mg, Ca and S increased; and a decrease in the amounts of total Na and K away from the host rock towards the heater was observed. At the boundary with the heater, an increase in the total Fe content, decreases in total Si and Al contents, precipitation of gypsum and anhydrite, dissolution of cristobalite and feldspars, and indications of the formation of trioctahedral clay minerals were observed. A decrease in swelling pressure for the Friedland clay (in drill-cored samples) was recorded which was recovered after grinding and recompaction. No effects of hydraulic conductivity were found, after 6.5 y of reaction time, in the subsurface of any of materials studied.

Keywords

chemistrymineralogynuclear waste disposalin situ testsFe–bentonite interactionswelling pressure
Type
Research Article
Information
Clay Minerals , Volume 51 , Issue 2 , May 2016 , pp. 129 - 144
Creative Commons
Creative Common License - CCCreative Common License - BY
Copyright © The Mineralogical Society of Great Britain and Ireland 2016 This is an Open Access article, distributed under the terms of the Creative Commons Attribution license. (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted re-use, distribution, and reproduction in any medium, provided the original work is properly cited.
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2016

References

Åkesson, M., Olsson, S., Dueck, A., Nilsson, U., Karnland, O., Kiviranta, L., Kumpulainen, S. & Linden, I. (2012) Temperature buffer test, Hydro-mechanical and chemical/mineralogical characterizations. P-12-06. Svensk Kärnbränslehantering AB (SKB), Stockholm, Sweden.Google Scholar
Ammann, L., Bergaya, F. & Lagaly, G. (2005) Determination of the cation exchange capacity of clays with copper complexes revisited. Clay Minerals, 40, 441–453.10.1180/0009855054040182Google Scholar
Belyayeva, N.I. (1967) Rapid method for the simultaneous determination of the exchange capacity and content of exchangeable cations in solonetzic soils. Soviet Soil Science, 1409-1413.Google Scholar
Dohrmann, R. & Kaufhold, S. (2010) Determination of exchangeable calcium of calcareous and gypsiferous bentonites. Clays and Clay Minerals, 58, 79–88.10.1346/CCMN.2010.0580108CrossRefGoogle Scholar
Dohrmann, R. & Kaufhold, S. (2014) Cation exchange and mineral reactions observed in MX80 buffer samples of the Prototype repository in situ experiment in Äspö, Sweden. Clays and Clay Minerals, 62, 357–373.10.1346/CCMN.2014.0620501Google Scholar
Dohrmann, R., Genske, D., Karnland, O., Kaufhold, S., Kiviranta, L., Olsson, S., Plötze, M., Sandén, T., Sellin, P., Svensson, D. & Valter, M. (2012a) Interlaboratory CEC and exchangeable cation study of bentonite buffer materials: I. Cu(II)-triethylenetetramine method. Clays and Clay Minerals, 60, 162–175.10.1346/CCMN.2012.0600206Google Scholar
Dohrmann, R., Genske, D., Karnland, O., Kaufhold, S., Kiviranta, L., Olsson, S., Plötze, M., Sandén, T., Sellin, P., Svensson, D. & Valter, M. (2012b) Interlaboratory CEC and exchangeable cation study of bentonite buffer materials: II. Alternative methods. Clays and Clay Minerals, 60, 176–185.10.1346/CCMN.2012.0600207Google Scholar
Dohrmann, R., Olsson, S., Kaufhold, S. & Sellin, P. (2013) Mineralogical investigations of the first package of the alternative buffer material test II. Exchangeable cation population rearrangement. Clay Minerals, 48, 215–233.10.1180/claymin.2013.048.2.05Google Scholar
Drever, J.I. (1973) The preparation of oriented clay mineral specimen for X-ray diffraction analysis by a filter-membrane peel technique. American Mineralogist, 58, 553–554.Google Scholar
Eng, A., Nilsson, U. & Svensson, D. (2007) Äspö Hard Rock Laboratory. Alternative Buffer Material. Installation report. SKB IPR-07-15. Svensk Kärnbränslehantering AB (SKB), Stockholm, Sweden.Google Scholar
Jackson, M.L. (1975) Soil Chemical Analysis —Advanced Course, 2nd edition. Published by the author, Madison, Wisconsin, USA, 991 pp.Google Scholar
Karnland, O., Olsson, S., Dueck, A., Birgersson, M., Nilsson, U., Hernan-Håkansson, T., Pedersen, K., Nilsson, S., Eriksen, T.E. & Rosborg, B. (2009) Long-term test of buffer material at the Äspö Hard Rock Laboratory, LOT project, Final report ontheA2 test parcel. TR-09-29. Svensk Kärnbränslehantering AB (SKB), Stockholm, Sweden.Google Scholar
Kaufhold, S., Dohrmann, R., Sandén, T., Sellin, P. & Svensson, D. (2013) Mineralogical investigations of the first package of the alternative buffer material test -I. Alteration of bentonites. Clay Minerals, 48, 199–213.10.1180/claymin.2013.048.2.04CrossRefGoogle Scholar
Kiviranta, L. & Kumpulainen, S. (2011) Quality control and characterization of bentonite materials. Posiva WR 2011-84. Posiva Oy, Olkiluoto, Finland.Google Scholar
Kumpulainen, S. & Kiviranta, L. (2010) Mineralogical and chemical characterization of various bentonite and smectite-rich clay materials. Posiva WR 2010-52. Posiva Oy, Olkiluoto, Finland.Google Scholar
Kumpulainen, S. & Kiviranta, L. (2011) Mineralogical, chemical and physical study of potential buffer and backfill materials from ABM test package 1. Posiva WR 2011-1. Posiva Oy, Olkiluoto, Finland.Google Scholar
Meier, L.P. & Kahr, G. (1999) Determination of the cation exchange capacity (CEC) of clay minerals using the complexes of copper(II) ion with triethylenetetramine and tetraethylenepentamine. Clays and Clay Minerals, 47, 386–388.10.1346/CCMN.1999.0470315CrossRefGoogle Scholar
Moore, D.M. & Reynolds, R.C. (1989) X-ray diffraction and the Identification and Analysis of Clay Minerals. Oxford University Press, New York.Google Scholar
Muurinen, A. (2010) Studies on the chemical conditions and microstructure in package 1 of Alternative Buffer Materials Project (ABM) in Äspö. Posiva WR 2010-11. Posiva Oy, Olkiluoto, Finland.Google Scholar
Newman, A.C.D. & Brown, G. (1987) The chemical constitution of clays. Pp. 1–128 in: Chemistry of Clays and Clay Minerals (A.C.D. Newman, editor). Mineralogical Society, Monograph no. 6. Longman Scientific & Technical, Essex, England.Google Scholar
Olsson, S., Jensen, V., Johannesson, L.-E., Hansen, E., Karnland, O., Kumpulainen, S., Kiviranta, L., Svensson, D., Hansen, S. & Lindén, J. (2013) Prototype repository. Hydro-mechanical, chemical and mineralogical characterization of the buffer and tunnel backfill material from the outer section of the Prototype Repository. TR-13-21. Svensk Kärnbränslehantering AB (SKB), Stockholm, Sweden.Google Scholar
Svensk Kärnbränslehantering, A.B. (2014) Äspö Hard Rock Laboratory, Annual Report 2013. TR-14-17, Svensk Kärnbränslehantering AB (SKB), Stockholm, Sweden.Google Scholar
Svensson, D. (2015) The Bentonite Barrier. Swelling Properties, Redox Chemistry and Mineral Evolution. Doctoral dissertation, Faculty of Engineering, Lund University, Sweden.Google Scholar
Svensson, D., Dueck, A., Nilsson, U., Olsson, S., Sandén, T., Lydmark, S., Jägerwall, S., Pedersen, K. & Hansen, S. (2011) Alternative buffer material. Status of the ongoing laboratory investigation of reference materials and test package 1. TR-11-06. Svensk Kärnbränslehantering AB (SKB), Stockholm, Sweden.Google Scholar