Abstract
The Nuclear Waste Management Organization (NWMO) is responsible for the design and implementation of Canada’s deep geological repository (DGR), which will be constructed ~ 500 m below ground surface to safely contain and isolate used nuclear fuel. Used fuel containers (UFC), designed by NWMO as part of multi-barrier system for DGR, comprises of an inner steel core with an outer copper layer that serves as a corrosion barrier. Surrounding the UFC, a highly compacted MX-80 bentonite (HCB) is used to suppress the transport of corrosive agents to the UFC and to limit the movement of radionuclides out of the DGR, in the highly unlikely event of a UFC failure. Under anaerobic conditions, sulfate-reducing bacteria at the interface of the host rock and bentonite may produce bisulfide (HS−) that can transport to the UFC surface and corrode the copper barrier. Therefore, it is crucial to understand HS− transport mechanisms through bentonite to assess the long-term DGR performance. Due to bentonite’s low permeability, HS− transport will be diffusion-driven; therefore, the apparent diffusion coefficient and retardation are critical parameters for the DGR performance assessment. This study aims to quantify HS− diffusion through bentonite using diffusion experiments under a range of anticipated DGR conditions (e.g., temperature, ionic concentration). This paper outlines the underpinning theory, experimental methodology developed to conduct experiments, and preliminary results. Altogether, this work bolsters confidence in the experimental design and methodology that will be used to determine necessary key parameters to model reactive transport of HS− through the DGR’s bentonite barrier.
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References
Hall DS, Behazin M, Jeffrey Binns W, Keech PG (2021) An evaluation of corrosion processes affecting copper-coated nuclear waste containers in a deep geological repository. Prog Mater Sci 118:100766
Ewing RC (2015) Long-term storage of spent nuclear fuel. Nat Mater 14(3):252–257
Briggs S, McKelvie J, Sleep B, Krol M (2017b) Multi-dimensional transport modelling of corrosive agents through a bentonite buffer in a Canadian deep geological repository. Sci Total Environ 599–600:348–354
Salonen T, Lamminmäki T, King F, Pastina B (2021) Status report of the finnish spent fuel geologic repository programme and ongoing corrosion studies. Mater Corros 72(1–2):14–24
Briggs S, McKelvie J, Keech P, Sleep B, Krol M (2017a) Transient modelling of sulphide diffusion under conditions typical of a deep geological repository. Corros Eng Sci Technol 52(sup1):200–203
García-Gutiérrez M, Cormenzana J, Missana T, Mingarro M, Molinero J (2006) Overview of laboratory methods employed for obtaining diffusion coefficients in FEBEX compacted bentonite. J Iber Geol 32(1):37–53
Shackelford CD, Moore SM (2013) Fickian diffusion of radionuclides for engineered containment barriers: Diffusion coefficients, porosities, and complicating issues. Eng Geol 152(1):133–147
Van Loon LR, Glaus MA, Müller W (2007) Anion exclusion effects in compacted bentonites: towards a better understanding of anion diffusion. Appl Geochem 22(11):2536–2552
Shen L, Chen Z (2007) Critical review of the impact of tortuosity on diffusion. Chem Eng Sci 62(14):3748–3755
Crank J (1979) The mathematics of diffusion. Oxford University Press
Bengtsson A, Pedersen K (2016) Microbial sulphate-reducing activity over load pressure and density in water saturated Boom Clay. Appl Clay Sci 132–133:542–551
Pedersen K, Bengtsson A, Blom A, Johansson L, Taborowski T (2017) Mobility and reactivity of sulphide in bentonite clays—Implications for engineered bentonite barriers in geological repositories for radioactive wastes. Appl Clay Sci 146:495–502
Dixon DA, Man A, Rimal S, Stone J, Siemens G (2018) Bentonite seal properties in saline water. In: NWMO TR-2018–20, Nuclear Waste Management Organization, Toronto, Ontario
Alinnor IJ (2007) Adsorption of heavy metal ions from aqueous solution by fly ash. Fuel 86(5):853–857
Xu D, Tan XL, Chen CL, Wang XK (2008) Adsorption of Pb(II) from aqueous solution to MX-80 bentonite: effect of pH, ionic strength, foreign ions and temperature. Appl Clay Sci 41(1):37–46
Gupt CB, Yamsani SK, Prakash A, Medhi CR, Sreedeep S (2019) Appropriate liquid-to-solid ratio for sorption studies of bentonite. J Environ Eng 145(2):04018138
Van Loon LR, Soler JM, Bradbury MH (2003) Diffusion of HTO, 36Cl−and 125I−in opalinus clay samples from mont terri: effect of confining pressure. J Contam Hydrol 61(1):73–83
Villar MV, Gómez-Espina R, Lloret A (2010) Experimental investigation into temperature effect on hydro-mechanical behaviours of bentonite. J Rock Mech Geotech Eng 2(1):71–78
Karnland O, Muurinen A, Karlsson F (2005) Bentonite swelling pressure in NaCl solutions–experimentally determined data and model calculations. In: Alonso EE, Ledesma A (eds), Advances in understanding engineered clay barriers: proceedings of the international symposium on large scale field tests in granite, sitges, Barcelona, Spain, 12–14 November 2003. CRC Press, pp 241–256
Karnland O, Olsson S, Nilsson U (2006) Mineralogy and sealing properties of various bentonites and smectite-rich clay materials. In: SKB-TR-06–30, Svensk Kärnbränslehantering AB, Swedish Nuclear Fuel and Waste Management Co.
Navarro V, De la Morena G, Yustres Á, González-Arteaga J, Asensio L (2017) Predicting the swelling pressure of MX-80 bentonite. Appl Clay Sci 149:51–58
Acknowledgements
Funding was provided by the Ontario Research Fund – Research Excellence grant and the Natural Sciences and Engineering Research Council of Canada Collaborative Research and Development Grant in partnership with the Nuclear Waste Management Organization (Toronto, Canada).
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Chowdhury, F. et al. (2023). Measuring Key Parameters Governing Anion Transport Through Mx-80 Bentonite. In: Walbridge, S., et al. Proceedings of the Canadian Society of Civil Engineering Annual Conference 2021 . CSCE 2021. Lecture Notes in Civil Engineering, vol 239. Springer, Singapore. https://doi.org/10.1007/978-981-19-0503-2_44
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DOI: https://doi.org/10.1007/978-981-19-0503-2_44
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