Hostname: page-component-848d4c4894-2pzkn Total loading time: 0 Render date: 2024-05-30T21:53:21.470Z Has data issue: false hasContentIssue false

Bentonite reactivity in alkaline solutions: interim results of the Cyprus Natural Analogue Project (CNAP)

Published online by Cambridge University Press:  09 July 2018

W. R. Alexander*
Affiliation:
Bedrock Geosciences, Auenstein, Switzerland
A. E. Milodowski
Affiliation:
British Geological Survey, Keyworth, UK
A. F. Pitty
Affiliation:
Pitty (EIA) Consulting, Norwich, UK
S. M. L. Hardie
Affiliation:
Scottish Universities Environmental Research Centre (SUERC), East Kilbride, UK
S. J. Kemp
Affiliation:
British Geological Survey, Keyworth, UK
J. C. Rushton
Affiliation:
British Geological Survey, Keyworth, UK
Andreas Siathas
Affiliation:
Geoinvest Ltd., Aglantzia, Cyprus
Avrim Siathas
Affiliation:
Geoinvest Ltd., Aglantzia, Cyprus
A. B. Mackenzie
Affiliation:
SUERC, East Kilbride, UK
P. Korkeakoski
Affiliation:
Posiva, Olkiluoto, Finland
S. Norris
Affiliation:
NDA-RWMD, Harwell, UK
P. Sellin
Affiliation:
SKB, Stockholm, Sweden
M. Rigas
Affiliation:
Geological Survey Department, Strovolos, Cyprus
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.

Bentonite is one of the more safety-critical components of the engineered barrier system in the disposal concepts developed for many types of radioactive waste. It is used due to its favourable properties (including plasticity, swelling capacity, colloid filtration, low hydraulic conductivity, high retardation of key radionuclides) and its stability in relevant geological environments. However, bentonite is unstable under alkaline conditions and this has driven interest in low-alkali cements (leachate pH of 10–11). To build a robust safety case, it is important to have supporting natural analogue data to confirm understanding of the likely long-term performance of bentonite. In Cyprus, the presence of natural bentonite in close proximity to natural alkaline groundwaters permits the zones of potential bentonite/alkaline water reaction to be studied as an analogy of the potential reaction zones in the repository. Here, the results indicate minimal volumetric reaction of bentonite, with production of a palygorskite secondary phase.

Type
Research Article
Creative Commons
Creative Common License - CCCreative Common License - BY
Copyright © The Mineralogical Society of Great Britain and Ireland 2013 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 2013

Footnotes

current address MCM International, Baden-Dättwil, Switzerland

References

Ahonen, L., Korkeakoski, P., Tiljander, M., Kivikoski, H. & Laaksonen, R. (2008) Quality Assurance of the Bentonite Material. Posiva Working Report WR 2008-33, Posiva, Eurajoki, Finland.Google Scholar
Alexander, W.R. & Milodowski, A.E., editors (2011) Cyprus Natural Analogue Project (CNAP) Phase II Final Report. Posiva Working Report WR 2011-08, Posiva, Eurajoki, Finland.Google Scholar
Alexander, W.R. & Milodowski, A.E., editors (2013) Cyprus Natural Analogue Project (CNAP) Phase IV Final Report. Posiva Working Report WR 2013-20, Posiva, Eurajoki, Finland (in press).Google Scholar
Alexander, W.R., Arcilla C.A. et al. (2008) A new natural analogue study of the interaction of lowalkali cement leachates and the bentonite buffer. Scientific Basis for Nuclear Waste Management, 31, 493–500.Google Scholar
Alexander, W.R., Milodowski, A.E. & Pitty, A.F., editors (2011) Cyprus Natural Analogue Project (CNAP) Phase III Final Report. Posiva Working Report WR 2011-77, Posiva, Eurajoki, Finland.Google Scholar
Alexander, W.R., McKinley, I.G. & Kawamura, H. (2013) The process of defining an optimal natural analogue programme to support national disposal programmes. Proceedings of a Workshop on Natural Analogues for Safety Cases of Repositories in Rock Sal, 4–6 September 2012. Braunschweig, Germany. NEA/OECD, Paris, France (in press).Google Scholar
Alonso, J., Garcia-Sineriz, J.L. et al. (2009) ESDRED Module 4 Report: Temporary Sealing Technology, Final Technical Report. EC Report, EC, Luxembourg.Google Scholar
Barnes, I. & O’Neill, J.R. (1969) The relationship between fluids in some fresh alpine-type ultramafics and possible modern serpentinisation, western United States. Geological Society of America Bulletin, 80, 1947–1960.10.1130/0016-7606(1969)80[1947:TRBFIS]2.0.CO;2Google Scholar
Bear, L.M. (1960) The Geology and Mineral Resources of the Akaki-Lythrodondha Area. Geological Survey Department Memoirs No. 3, GSD, Lefkosia, Cyprus.Google Scholar
Bonatti, E. & Joensuu, O. (1968) Palygorskite from Atlantic deep sediments. American Mineralogist, 53, 975–983.Google Scholar
Boronina, A.V., Balderer, W., Renard, P. & Stichler, W. (2005) Study of stable isotopes in the Kouris catchment (Cyprus) for the description of the regional groundwater flow. Journal of Hydrology 308, 214–226.10.1016/j.jhydrol.2004.11.001Google Scholar
Botha, G. & Hughes, J.C. (1992) Pedogenic palygorskite and dolomite in a late Neogene sedimentary succession, northwestern Transvaal, South Africa. Geoderma, 53, 139–154.10.1016/0016-7061(92)90027-5Google Scholar
Bradbury, M.H. & Baeyens, B. (2002) Porewater Chemistry in Compacted, Re-saturated MX-80 Bentonite: Physico-Chemical Characterisation and Geochemical Modelling. PSI Report 02-10, PSI, Villigen, Switzerland.Google Scholar
Chapman, N.A., McKinley, I.G. & Smellie, J.A.T. (1984) The Potential of Natural Analogues in Assessing Systems for Deep Disposal of High-Level Radioactive Waste. Nagra Technical Report NTB 85-41, Nagra, Wettingen, Switzerland.Google Scholar
Christidis, G.E. (2006) Genesis and compositional heterogeneity of smectites. Part III: Alteration of basic pyroclastic rocks – a case study from the Troodos Ophiolite Complex, Cyprus. American Mineralogist, 91, 685–701.10.2138/am.2006.2001CrossRefGoogle Scholar
ECOCLAY (2005) ECOCLAY II: Effects of Cement on Clay Barrier Performance – Phase II. EC Nuclear Science and Technology Final Report EUR 21921, EC, Luxembourg.Google Scholar
Gass, I.D., MacCleod, C.J., Murton, B.J., Panayiotou, A., Simonian, K.O. & Xenophontos, C. (1994) The Geology of the Southern Troodos Transform Fault Zone. Geological Survey Department Memoir no.9, GSD, Lefkosia, Cyprus.Google Scholar
Heikola, T., Kumpulainen, S., Vuorinen, U., Kiviranta, L. & Korkeakoski, P. (2013) Influence of alkaline (pH 8.3–12.0) and saline solutions on chemical, mineralogical and physical properties of two different bentonites – batch experiments at 25 and 60°C. Clay Minerals, 48, xxx–xxx.10.1180/claymin.2013.048.2.12Google Scholar
Hillier, S., Suzuki, K. & Cotter-Howells J. (2001) Quantitative determination of cerussite (lead carbonate) by X-ray powder diffraction and inferences for lead speciation and transport in stream sediments from a former lead mining area of Scotland. Applied Geochemistry, 16, 597–608.10.1016/S0883-2927(00)00059-7CrossRefGoogle Scholar
Krekeler, M.P.S., Hammerley, E., Guggenheim, S. & Rakovan, J. (2005) Microscopy studies of the palygorskite to smectite transformation. Clays and Clay Minerals, 53, 92–99.10.1346/CCMN.2005.0530109Google Scholar
Metcalfe, R. & Walker, C. (2004) Proceedings of the International Workshop on Bentonite-Cement Interaction in Repository Environments 14–16 April 2004, Tokyo, Japan. NUMO Technical Report NUMO-TR-04-05, NUMO, Tokyo, Japan.Google Scholar
Miller, W.M., Alexander, W.R., Chapman, N.A., McKinley, I.G. & Smellie, J.A.T. (2000) Geological Disposal of Radioactive Wastes and Natural Analogues. Waste management series, 2, Pergamon, Amsterdam, The Netherlands.Google Scholar
NDA (2010) Geological Disposal: Near Field Evolution Status Report. NDA Report No. NDA/RWMD/033. NDA-RWMD, Harwell, UK.Google Scholar
Neal, C. & Shand, P. (2002) Spring and surface water quality of the Cyprus Ophiolites. Hydrology and Earth System Sciences, 6, 797–817.10.5194/hess-6-797-2002Google Scholar
Neaman, A., Pelletier, M. & Villieras, F. (2003) The effects of exchanged cation, compression, heating and hydration on textural properties of bulk bentonite and its corresponding purified montmorillonite. Applied Clay Science, 22, 153–168.10.1016/S0169-1317(02)00146-1Google Scholar
Pitty, A.F., MacKenzie, A.B., Milodowski, A.M. & Alexander, W.R. (2013) Dating the initiation of groundwater circulation: an example from the Troodos Massif, Cyprus. Geomorphology (in preparation).Google Scholar
Rochelle, C.A., Pearce, J.M., Bateman, K., Coombs, P. & Wetton, P.D. (1997) The evaluation of chemical mass transfer in the disturbed zone of a deep geological disposal facility for radioactive wastes. X: Interaction between synthetic cement porefluids and BVG: Observations from experiments of 4, 9 and 15 months duration. British Geological Survey (BGS), Fluid Processes and Waste Management Group Report, WE/97/16C, 79pp. BGS, Keyworth, UK.Google Scholar
Rozalen, M., Huertas, F.J. & Brady, P.V. (2009) Experimental study of the effect of pH and temperature on the kinetics of montmorillonite dissolution. Geochimica et Cosmochimica Acta, 73, 3752–3766.10.1016/j.gca.2009.03.026Google Scholar
Savage, D. & Benbow, S. (2007) Low pH Cements. SKI Report 2007:32. Swedish Radiation Safety Authority (SSM), Stockholm, Sweden.Google Scholar
Savage, D., Noy, D. & Mihara, M. (2002) Modelling the interaction of bentonite with hyperalkaline fluids. Applied Geochemistry, 17, 207–223.10.1016/S0883-2927(01)00078-6Google Scholar
Savage, D., Arthur, R., Watson, C. & Wilson, J. (2010) An Evaluation of Models of Bentonite Pore Water Evolution. Swedish Radiation Safety Authority (SSM) Report 2010-12, SSM, Stockholm, Sweden.Google Scholar
Sellin, P., Karlsson, F., Werme, L., Spahiu, K. & Puigdomenech, I. (2003) Effect of pH on the safety of KBS-3 deep repository and the confidence in safety assessments. Proceedings of a Workshop on Qualification of Low pH Cement for a Geological Repository, Oct 15–16, 2003, Stockholm. SKB, Stockholm, Sweden.Google Scholar
Singer, A. (1991) Palygorskite in sediments: Detrital, diagenetic or neoformed – A critical review. Geologische Rundschau, 68, 996–1008.Google Scholar
Wilson, J., Savage, D., Bond, A., Watson, S., Pusch, R. & Bennett, D. (2011) Bentonite: a Review of Key Properties, Processes and Issues for Consideration in the UK Context. Quintessa Report QRS-1378ZG- 1.1 for the NDA-RWMD, Quintessa, Henley-on- Thames, Oxfordshire, UK.Google Scholar