Hostname: page-component-78c5997874-94fs2 Total loading time: 0 Render date: 2024-11-18T10:47:12.024Z Has data issue: false hasContentIssue false
  • English
  • Français

Clay mineralogical investigations related to nuclear waste disposal

Published online by Cambridge University Press:  09 July 2018

F. T. Madsen
F. T. Madsen*
Affiliation:
Laboratory for Clay Mineralogy, Division of Geotechnical Engineering, Swiss Federal Institute of Technology, CH-8092 Zurich, Switzerland
Get access Rights & Permissions [Opens in a new window]

Abstract

Mineralogical and geotechnical investigations on the possible use of compacted bentonite as a buffer material in nuclear waste repositories are reported. The swelling capacity is highly dependent on the density of the compacted bentonite. Swelling pressures >30 MPa were measured for dry densities of ~2.0 g/cm3. Added iron or magnetite powder up to 20 wt% had no influence on the swelling capacity. Compacted mixtures of 20 wt% ground set cement and bentonite showed higher swelling pressures but lower swelling strain capability than compacted bentonite alone. Steam lowered the swelling pressure of compacted bentonite to ~60% of the original value. The influence was, however, reversible by ultrasonic treatment. The thermal conductivity of saturated compacted bentonite at a density of 2.0-2.1 g/cm3 is ~1.35-1.45 W/m°K The volumetric heat capacity ranges from 3.1 x 106 to 3.4 x 106 j/m3°C The saturated hydraulic conductivity of the compacted bentonite is <10-12 m/s. The apparent diffusion coefficients for various ions in compacted bentonite for water contents in the range of 20 to 25 wt% are: K+: 5 x 10-11, Cs+: 6 x 10-12, Sr2+: 3 x 10-11, UO22+: <10-13, Th4+: <10-13, Fe2+: 4 x 10-11, Fe3+: 4 x 10-11, Cl-: 1 x 10-10 and I- : 1 x 10-10 m2/s. The 'breakthrough time' for an apparent diffusion coefficient of 10-11 m2/s in compacted bentonite 1 m thick was estimated to be ~3000 years. The mineralogical longevity was investigated on natural K-bentonites from Kinnekulle, Sweden, and Montana, USA. Although these materials have undergone considerable changes during diagenesis and contain various amounts of mixed-layer illite-smectite, they still have a substantial swelling and adsorption capacity. The investigations demonstrate that although the properties of bentonite are negatively influenced to a certain extent by heat, hot steam, iron and cement, compacted bentonite is still the best choice to act as a buffer material in a nuclear waste repository.

Type
Research Article
Information
Clay Minerals , Volume 33 , Issue 1 , March 1998 , pp. 109 - 129
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1998

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

Ayranci, B. (1977) The major-, minor- and trace-element analysis of silicate rocks and minerals from a single sample solution. Schweiz. Mineral. Petrogr. Mitt. 57, 299–312.Google Scholar
Brandberg, F. & Skagius, K. (1991) Porosity, sorption and diffusivity data compiled for the SKB91 study. SKB Technical Report TR 91-16, SKB, Stockholm, Sweden.Google Scholar
Bucher, F. & Miiller-Vonmoos, M. (1989) Bentonite as a containment barrier for the disposal of highly radioactive waste. Appl. Clay Sci. 4, 157–177.CrossRefGoogle Scholar
Bucher, F. & Spiegel, U. (1984) Quelldruck von hochverdichteten Bentoniten. NTB 84-18. Nagra, Hardstrasse 73, CH-5430 Wettingen, Schweiz.Google Scholar
Bucher, F., Jeger, P., Kahr, G. & Lehner, J. (1982) Herstellung und Homogenitgt hochverdichteter Bentonitproben. NTB 82-05. Nagra, Hardstrasse 73, CH-5430 Wettingen, Schweiz.Google Scholar
Bucher, F., Kahr, G., Madsen, F.T. & Mayor, P.-A. (1993) Wechselwirkung von abgebundenem Zement mit verdichtetem Bentonit: Quelldruckversuche mit anschliessenden mineralogischen Untersuchungen. NTB 93-25. Nagra, Hardstrasse 73, CH-5430 Wettingen, Schweiz.Google Scholar
Calvet, R. & Chaussidon, J. (1969) Diffusion des cations compensateurs dans la montmorillonite aux faibles hydrations. Proc. lnt. Clay Conf. Tokyo, 635–647.Google Scholar
Cho, W.J., Oscarson, D.W., Gray, M.N. & Cheung, S.C.H. (1993) Influence of diffusant concentration on diffusion coefficients in clay. Radiochim. Acta, 60, 159–163.Google Scholar
Demberg, W. (1991) Ober die Ermittlung des Wasseraufnahmeverm6gens feink6rniger B6den mit dem Gereit nach Enslin-Neff. Geotechnik, 14, 125–131.Google Scholar
Eikenberg, J. (1992) Geochemische Speziationsrechnungen zur Bentonitdegradation durch Zementporenwsser. lnterner Bericht Paul Scherrer Institut, TM 41-92-14.Google Scholar
Eriksen, J., Jacobsson, A. & Pusch, R. (1981) Ion diffusion through highly compacted bentonite. SKB 81-06, Stockholm, Sweden.Google Scholar
Gast, R.G. & Mortland, M.M. (1971) Self diffusion of alkylammonium ions in montmorillonite. J. Colloid Sci. 37, 80–92.CrossRefGoogle Scholar
Gerstel, Z. & Banin, A. (1980) Fe2+-Fe3+ transformations in clay and resin ion exchange-system. Clays Clay Miner. 28, 335–345.Google Scholar
Grauer, R. (1988) Zum chemischen Verhalten von Montmorillonit in einer Endlagerverfullung. NTB 88-24. Nagra, Hardstrasse 73, CH-5430 Wettingen, Schweiz.Google Scholar
Grim, R.E. & Güven, N. (1978) Bentonites. Elsevier, N.Y. Google Scholar
Haas, R., Ph., Teysseire & Bucher, F. (1994) Einfluss yon Wasserdampf auf das Quellpotential von Bentonit. NTB 94-15. Nagra, Hardstrasse 73, CH-5430 Wettingen, Schweiz (in press).Google Scholar
Hofmann, E.-G. & Jagodzinski, H. (1955) Eine neue, hochaufliisende R6ntgenfeinstruktur-Anlage mit verbessertem, fokussierendem Monochromator und Feinfokusrohre. Zeitschrifi fur Metallkunde, 46, 601–609.Google Scholar
Hsu, K.J. (1989) Physical Principles of Sedimentology. Springer Verlag, Berlin.Google Scholar
Kahr, G. & Madsen, F.T. (1995) Determination of the cation exchange capacity and the surface area of bentonite, illite and kaolinite by methylene blue adsorption. Appl. Clay Sci. 9, 327-336.CrossRefGoogle Scholar
Kahr, G. & Müller-Vonmoos, M. (1982) Wärmeleitfähigkeit von Bentonit MX-80 und von Montigel nach der I-eidrahtmethode. NTB 82-06. Nagra, Hardstrasse 73, CH-5430 Wettingen, Schweiz.Google Scholar
Kahr, G., Hasenpatt, R. & Müller-Vonmoos, M. (1985) Ionendiffusion in hochverdichtetem Bentonit. NTB 85-23. Nagra, Hardstrasse 73, CH-5430 Wettingen, Schweiz.Google Scholar
Kahr, G., Kraehenbuehl, F., Müller-Vonmoos, M. & Stoeckli, H.F. (1986) Wasseraufnahme und Wasserbewegung in hochverdichtetem Bentonit. NTB 86-14. Nagra, Hardstrasse 73, CH-5430 Wettingen, Schweiz.Google Scholar
Kahr, G., Kraehenbuehl, F., Stoeckli, H.F. & Müller-Vonmoos, M. (1990) Study of the water-bentonite system by vapour adsorption, immersion calorimetry and X-ray techniques: II. Heats of immersion, swelling pressuresi and thermodynamic properties. Clay Miner. 25, 499–506.Google Scholar
Knutsson, S. (1983) On the thermal conductivity and thermal diffusivity of highly compacted bentonite. SKBF Technical KBS Report 83-72. SKB, Sweden.Google Scholar
Köster, H.M. (1977) Die Berechnung kristallchemischer Strukturformeln von 2:l-Schichtsilikaten unter Berücksichtigung der gemessenen Zwischen-schichtladungen und Kationenaustauschkapazitäten, sowie die Darstellung der Ladungsverteilung in der Struktur mittels Dreieckskoordinaten. Clay Miner. 12, 45–54.Google Scholar
Kraehenbuehl, F., Stoeckli, H.F., Brunner, F., Kahr, G. & Mfiller-Vonmoos, M. (1987) Study of the waterbentonite system by vapour adsorption, immersion calorimetry and X-ray techniques: I. Micropore volumes and internal surface areas, following Dubinin's theory. Clay Miner. 22, 1–9.CrossRefGoogle Scholar
Lagaly, G. & Weiss, A. (1971) Neue Methoden zur Charakterisierung und Identifizierung quellungsfahiger Dreischichttonminerale. Z. Düng., Bodenkunde 130, 9–24.Google Scholar
Mackenzie, R.C. (1951) A micromethod for determination of cation-exchange-capacity of clay mine. Sci. 6, 219–222.Google Scholar
Madsen, F.T. & Kahr, G. (1991) Diffusion von E-and Jodid-Ionen in hochverdichtetem Bentonit. ATB 91-28. Nagra, Hardstrasse 73, CH-5430 Wettingen, Schweiz.Google Scholar
Madsen, F.T. & Kahr, G. (1993a) Diffusion of ions in compacted bentonite. Proc. Int. Conf. Nuclear Waste Management and Environmental Remediation, Praha, 239-246.Google Scholar
Madsen, F.T. & Kahr, G. (1993b) Wasser-dampfadsorption und spezifische Oberfläche von Tonen. Berichte der Deutschen Ton- und Tonmineralgruppe. Beitriäge zur Jahrestagung Hannover, 9.-11.9.1992. H. Graf v. Reichenbach (Herausgeber), 165–180.Google Scholar
Madsen, F.T. & Müller-Vonmoos, M. (1989) The swelling behaviour of clays. Appl. Clay Sci. 4, 143–156.CrossRefGoogle Scholar
Marshall, C.E. (1935) Layer lattices and the baseexchange clays. Z. Krist. 91 A, 433-449.Google Scholar
Milodowski, A.E., Hudges, C.R., Kemp, S.J. & Pearce, J.M. (1990) Characterisation of bentonite alteration in reacted cement-bentonite blocks from swellingtests experiments. British Geological Survey Technical Report, WG/90/39C.Google Scholar
Müller-Vonmoos, M. (1971) Zur Komgrössenfraktionierung tonreicher Sedimente. Schweiz. Min. Petr. Mitt. 51, 245–257.Google Scholar
Müller-Vonmoos, M. & Kahr, G. (1982) Bereitstellung von Bentoniten für Laboruntersuchungen. NTB 82-04. Nagra, Hardstrasse 73, CH-5430 Wettingen, Schweiz.Google Scholar
Müller-Vonmoos, M. & Kahr, G. (1983) Mineralogische Untersuchungen von Wyoming Bentonit MX-80 und Montigel. NTB 83-12. Nagra, Hardstrasse 73, CH-5430 Wettingen, Schweiz.Google Scholar
Müller-Vonmoos, M. & Kahr, G. (1985) Langzeitstabilität yon Bentonit unter Endlagerbedingungen. NTB 85-25. Nagra, Hardstrasse 73, CH-5430 Wettingen, Schweiz.Google Scholar
Müller-Vonmoos, M., Kahr, G. & Madsen, F.T. (1994) Intracrystalline swelling of mixed-layer illite-smectire in K-bentonites. Clay Miner. 29, 205–213.Google Scholar
Müller-Vonmoos, M., Kahr, G., Bucher, F. & Madsen, F.T. (1990) Investigation of Kinnekulle K-bentonite aimed at assessing the long-term stability of bentonites under repository conditions. Engin. Geol. 28, 269–280.CrossRefGoogle Scholar
Müller-Vonmoos, M., Bucher, F., Kahr, G., Madsen, F.T. & Mayor, P.-A. (1991a) Wechsellagerungen und Quellverhalten von Kalium-Bentoniten. NTB 91-13. Nagra, Hardstrasse 73, CH-5430 Wettingen, Schweiz.Google Scholar
Müller-Vonmoos, M., Kahr, G., Bucher, F., Madsen, F.T. & Mayor, P.-A. (1991b) Untersuchungen zum Verhalten yon Bentonit in Kontakt mit Magnetit und Eisen unter Endlagerbedingungen. NTB 91-14. Nagra, Hardstrasse 73, CH-5430 Wettingen, Schweiz.Google Scholar
Nagra (1985) Project ‘Gewiihr 1985” Feasibility and safety studies for final disposal of radioactive wastes in Switzerland. Nagra, Hardstrasse 73, CH-5430 Wettingen, Schweiz.Google Scholar
Neretnieks, I. (1982) Diffusivities of some dissolved constituents in compacted wet bentonite clay MX-80 and the impact of radionuclide migration in the buffer. SKB 82-27, Stockholm, Sweden.Google Scholar
Oscarson, D.W., Hume, H.B., Sawatsky, N.G. & Cheung, S.C.H. (1992) Diffusion of Iodide in compacted bentonite. Soil Sci. Soc. Am. J. 56, 1400–1406.Google Scholar
Oscarson, D.W., Dixon, D.A. & Hume, H.B. (1996) Mass transport through defected bentonite plugs. Appl. Clay Sci. 11, 127–142.CrossRefGoogle Scholar
Piper, C.S. (1944) Soil and Plant Analysis, pp. 130-132. Interscience Publishers, N.Y. Google Scholar
Pusch, R. (1992) Investigations of a clay profile on southern Gotland of presumed value for documentation of smectite/illite conversion. SKB 92-74. SKB, Stockholm, SwedenGoogle Scholar
Pusch, R. (1995) Selection of buffer materials with special respect to their performance in a long-term perspective. SKB Arbetsrapport 95-21. SKB, Stockholm, Sweden.Google Scholar
Pusch, R. (1996) Microstructural modelling of smectitic buffers and backfills. SKB Progress Report U-96-28. SKB, Stockholm, Sweden.Google Scholar
Pusch, R. & Madsen, F.T. (1993) Aspects of the illitization of the Kinnekulle bentonites. SKB Arbetsrapport 93-48. SKB, Stockholm, Sweden.Google Scholar
Pusch, R. & Madsen, F.T. (1995) Aspects of the itlitization of the Kinnekulle bentonites. Clays Clay Miner. 43, 261–270.Google Scholar
Pusch, R., Börgesson, L. & Erlström, M. (1987) Alteration of isolating properties of dense smectite clay in repository environments as examples by seven pre-Quartemary clays. SKB Technical Report TR 87-29. SKB, Stockholm, Sweden.Google Scholar
Pusch, R., Hökmark, H. & Karnland, O. (1990) Microstructural impact on the conductivity of smectite buffer clays. Proc. 9th. Int. Clay Conf. Strasbourg, II, 127-137.Google Scholar
Pusch, R., Börgesson, L. Frederikson, A., Johannesson, L.-E., Hökmark, H., Kamland, O. & Sandén, T. (1994) The buffer and backfill encyclopedia, Part. I. SKB Technical Report. SKB, Stockholm, Sweden.Google Scholar
Robin, M.J.L., Gillham, R.W. & Oscarson, D.W. (1987) Diffusion of strontium and chloride in compacted clay-based materials. Soil Sci. Soc. Am. J. 51, 1102–1108.Google Scholar
Sawatsky, N.G. & Oscarson, D.W. (1991) Diffusion of technetium in dense bentonite under oxidizing and redusing conditions. Soil Sci. Soc. Am. J. 55, 1261–1267.Google Scholar
Schmidt, K.G. (1954) Der Phosphorsäiureaufschluss zur Bestimmung des Gehaltes an freier Kieselsäiure. Ber. DKG 31, 402–404.Google Scholar
Scott, H.D. & Phillips, R.E. (1973) Self diffusion coefficients of selected herbicides in water and estimates of their transportation factors in soil. Soil Sci. Soc. Am. Proc. 37, 965–967.Google Scholar
Thomas, G.W. & Coleman, N.T. (1964) The fate of exchangeable iron in acid clay systems. Soil Sci. 97, 229–232.CrossRefGoogle Scholar
Torstenfelt, B. (1986a) Migration of the fission products Strontium, Technetium, Iodine and Cesium in clay. Radiochim. Aeta 39, 97–104.Google Scholar
TorstenfeIt, B. (1986b) Migration of the actenides Thorium, Protactinium, Uranium, Neptunium, Plutonium and Americum in clay. Radiochim. Acta 39, 105–112.Google Scholar
Torstenfelt, B., Andersson, K., KJpatsi, H., Allard, B. & Olofsson, U. (1982) Diffusion measurements in compacted bentonite. Scientific Basis for Nuclear Waste Management. St. V. Topp, ed., Elsevier, 295-302.Google Scholar
van Olphen, H. (1977) An Introduction to Clay Colloid Chemistry. 2nd ed., Wiley, N.Y.Google Scholar