Hostname: page-component-cd9895bd7-jkksz Total loading time: 0 Render date: 2024-12-27T12:05:40.133Z Has data issue: false hasContentIssue false
  • English
  • Français

Characterizing mineralogy and redox reactivity in potential host rocks for a UK geological disposal facility

Published online by Cambridge University Press:  02 January 2018

J. Quirke ,
C. M. B. Henderson ,
R. A. D. Pattrick ,
K. M. Rosso ,
A. Dent ,
J. W. Sharples  and
C. I. Pearce
J. Quirke
Affiliation:
School of Chemistry and Dalton Nuclear Institute, University of Manchester, Oxford Road, Manchester M13 9PL, UK
C. M. B. Henderson
Affiliation:
School of Earth, Atmospheric and Environmental Sciences, University of Manchester, Oxford Road, Manchester M13 9PL, UK ASTeC, STFC Daresbury Laboratory, Warrington WA4 4AD, UK
R. A. D. Pattrick
Affiliation:
School of Earth, Atmospheric and Environmental Sciences, University of Manchester, Oxford Road, Manchester M13 9PL, UK
K. M. Rosso
Affiliation:
School of Earth, Atmospheric and Environmental Sciences, University of Manchester, Oxford Road, Manchester M13 9PL, UK Pacific Northwest National Laboratory, Richland, Washington, 99352, USA
A. Dent
Affiliation:
Diamond Light Source, Didcot, Oxfordshire OX11 0DE, UK
J. W. Sharples
Affiliation:
Photon Science Institute, University of Manchester, Oxford Road, Manchester M13 9PL, UK
C. I. Pearce*
Affiliation:
School of Chemistry and Dalton Nuclear Institute, University of Manchester, Oxford Road, Manchester M13 9PL, UK
*
*E-mail: Carolyn.Pearce@manchester.ac.uk
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.

Geological disposal facilities (GDF) are intended to isolate and contain radioactive waste within multiple protective barriers, deep underground, to ensure that no harmful quantities of radioactivity reach the surface environment. The last line of defense in a multi-barrier GDF is the geosphere, where iron is present in the host rock mineralogy as either Fe(II) or Fe(III), and in groundwater as Fe(II) under reducing conditions. The mobility of risk-driving radionuclides, including uranium and technetium, in the environment is affected significantly by their valence state. Due to its low redox potential, Fe(II) can mediate reduction of these radionuclides from their oxidized, highly mobile, soluble state to their reduced, insoluble state, preventing them from reaching the biosphere. Here a study of five types of potential host rocks, two granitoids, an andesite, a mudstone and a clay-rich carbonate, is reported. The bulk rocks and their minerals were analysed for iron content, Fe(II/III) ratio, and for the speciation and fine-grained nature of alteration product minerals that might have important controls on groundwater interaction. Total iron content varies between 0.9% in clays to 5.6% in the andesite. X-ray absorption spectroscopy reveals that Fe in the granitoids and andesite is predominantly Fe(II), and in mudstones, argillaceous limestone and terrestrial sandstone is predominantly Fe(III). The redox reactivity of the potential host rocks both in the presence and absence of Fe(II)-containing 'model' groundwater was investigated using an azo dye as a probe molecule. Reduction rates as determined by reactivity with the azo dye were correlated with the ability of the rocks to uptake Fe(II) from groundwater rather than with initial Fe(II) content. Potential GDF host rocks must be characterized in terms of mineralogy, texture, grain size and bulk geochemistry to assess how they might interact with groundwater. This study highlights the importance of redox reactivity, not just total iron and Fe(II)/(III) ratio, when considering the host rock performance as a barrier material to limit transport of radionuclides from the GDF.

Keywords

geosphereiron-bearing mineralsFE(II)/FE(iii) ratioreducing potentialX-ray absorption spectroscopygranitoidsandesitemudstoneclay-rich carbonate
Type
Research Article
Information
Mineralogical Magazine , Volume 79 , Issue 6 , November 2015 , pp. 1353 - 1367
Creative Commons
Creative Common License - CCCreative Common License - BY
Copyright © The Mineralogical Society of Great Britain and Ireland 2015. This is an open access article, distributed under the terms of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2015

References

ANDRA (2005) Synthesis: Evaluation of the feasibility of a geological repository in an argillaceous formation Meuse/Haute-Marne site. ANDRA Report Series. ANDRA, Châtenay-Malabry, France.Google Scholar
Barron, A.J.M., Lott, G.K. and Riding, J.B. (2012) Stratigraphical framework for the Middle Jurassic strata of Great Britain and the adjoining continental shelf. Geology and Landscape Programme Research Report RR/11/06. British Geological Survey, Keyworth, UK.Google Scholar
Bossart, P. and Wermeille, S. (1999) The Mont Terri rock laboratory. In: Results of the hydrogeological, geo-chemical and geotechnical experiments performed in the Opalinus Clay (1996-1997) (M. Thury and P. Bossart, editors). Geological report No. 23, Swiss Geological Survey.Google Scholar
Burley, S.D. (1984) Patterns of diagenesis in the Sherwood Sandstone (Triassic), UK. Clay Minerals, 19, 403–440.CrossRefGoogle Scholar
Deer, W.A., Howie, R.A. and Zussman, J. (1962) Sheet Silicates. Longman, London.Google Scholar
Department of Energy & Climate Change (2014) Implementing Geological Disposal. Department of Energy & Climate Change, London.Google Scholar
Droop, G.T.R. (1987) A general equation for estimating Fe3+ concentrations in ferromagnesian silicates and oxides from microprobe analyses, using stoichio-metric criteria, MineralogicalMagazine, 51, 431–435 Google Scholar
Fleet, M.E. (2003) Rock-Forming Minerals, Vol. 3A: Micas. The Geological Society, London, pp. 765.Google Scholar
Gustafsson, H., Hallbeck, M., Norell, M., Lindgren, M., Engström, M., Rosén, A. and Zachrisson, H. (2014) Fe(III) distribution varies substantially within and between atherosclerotic plaques. Magnetic Resonance in Medicine, 71, 885–892.CrossRefGoogle ScholarPubMed
Hesselbo, S.P. (2008) Sequence stratigraphy and inferred relative sea-level change from the onshore British Jurassic. Proceedings. of the Geological Association, 119, 19–34 CrossRefGoogle Scholar
Holliday, D.W., Jones, N.S. and McMillan, A.A. (2005) Lithostratigraphical subdivision of the Sherwood Sandstone Group (Triassic) of the northeastern part of the Carlisle Basin, Cumbria, and adjacent parts of Dumfries and Galloway, UK. Geology & Landscape Northern Britain Programme Internal Report IR/05/ 148. British Geological Survey, Keyworth, UK.Google Scholar
Kiriakoulakis, K., Marshall, J.D. and Wolff, G.A. (2000) Biomarkers in a Lower Jurassic concretion from Dorset (UK). Journal of the Geological Society, 157, 207–220.CrossRefGoogle Scholar
Liu, J., Pearce, C.I., Qafoku, O., Arenholz, A., Heald, S. M and Rosso, K.M. (2012) Tc(VII) reduction kinetics by titanomagnetite (Fe3_xTix04) nanoparticles. Geochimica et Cosmochimica Acta, 92, 67–81.CrossRefGoogle Scholar
MacQuaker, J.H.S. (1994) A lithofacies study of the Peterborough Member, Oxford Clay mudstone suc-cession Formation (Jurassic), UK: an example of sediment bypass in a mudstone sequence. Journal of the Geological Society, 151, 161–172.CrossRefGoogle Scholar
Millward, D. (2004) A stratigraphical framework for the upper Ordovician and Lower Devonian volcanic and intrusive rocks in the English Lake District and adjacent areas. Integrated Geoscience Surveys (North) Programme Research Report RR/01/07. British Geological Survey, Keyworth, UK.Google Scholar
Milodowski, A.E., Gillespie, M.R., Naden, J., Fortey, N.J., Shepherd, T.J., Pearce, J.M. and Metcalfe, R. (1998) The petrology and paragenesis of fracture mineralization in the Sellafield area, West Cumbria. Proceedings of the Yorkshire Geological Society, 52, 215–241.CrossRefGoogle Scholar
Nuclear Decommissioning Authority [NDA] (2010) Geological Disposal: Generic Environmental Safety Case main report. NDA report no. NDA/RWMD/021. Didcot, UK.Google Scholar
Oliver, G.J.H., Smellie, J.L., Thomas, L.J., Casey, D.M., Kemp, A.E.S., Evans, L.J., Baldwin, J.R. and Hepworth, B.C. (1984) Early Palaeozoic metamorphic history of the Midland Valley, the Southern Uplands-Longford-Down massif and the Lake District, British Isles. Transactions of the Royal Society of Edinburgh: Earth Science, 75, 259–273.Google Scholar
Pearce, C.I., Christie, R., Boothman, C., von Canstein, H., Guthrie, J.T and Lloyd, J.R. (2006) Reactive azo dye reduction in Shewanella strain J18 143. Biotechnology andBioengineering, 95, 692–703.CrossRefGoogle ScholarPubMed
Peters, T.J. and Hofmann, B. (1984) Hydrothermal clay mineral formation in a biotite granite in northern Switzerland. Clay Minerals, 19, 579–590.CrossRefGoogle Scholar
Plötze, M., Wolf, D. and Krbetschek, M.R. (2012) Gamma-irradiation dependency of EPR and TL-spectra of quartz. Pp. 177-190 in: Quartz: Deposits, Mineralogy and Analytics (J. Götze, and R. Möckel, editors). Springer, Berlin.Google Scholar
Psyrillos, A., Howe, J.H., Manning, D.A.C. and Burley, S. D (1999) Geological controls on kaolin particle shape and consequences for mineral processing. Clay Minerals, 34, 193–208.CrossRefGoogle Scholar
Simpson, B. (1934) The petrology of the Eskdale (Cumberland) Granite. Proceedings of the Geological Association, XLV, 17–34.Google Scholar
Svensk Kärnbränslehantering [SKB] (2005) Extended consultations according to the environmental code. EnaInfo/Edita Norstedts Tryckeri, Swedish Nuclear Fuel and Waste Management Co, Stockholm.Google Scholar
Stephens, M.B. (2010) Forsmark site investigation: Bedrock geology — overview and excursion guide. SKB R-10-04. Svensk Kärnbränslehantering, Swedish Nuclear Fuel and Waste Management Co, Stockholm, pp. 52.Google Scholar
Stookey, L.L. (1970) Ferrozine - A new spectrophotometric reagent for iron. Analytical Chemistry, 42, 779–781.CrossRefGoogle Scholar
Young, B., Fortey, N.J. and Nancarrow, P.H.A. (1986) An occurrence of tungsten mineralisation in the Eskdale Intrusion, West Cumbria. Proceedings of the Yorkshire Geological Society, 46, 15–21.CrossRefGoogle Scholar
Zachara, J.M., Heald, S.M., Jeon, B.-H., Kukkadapu, R. K, Liu, C., McKinley, J.P., Dohnalkova, A.C. and Moore, D.A. (2007) Reduction of pertechnetate [Tc (VII)] by aqueous Fe(II) and the nature of solid phase redox products. Geochimica et Cosmochimica Acta, 71, 2137–2157.CrossRefGoogle Scholar