1887
Volume 1, Issue 1
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Abstract

The High Temperature Effects on Bentonite Buffers (HotBENT) Experiment, conducted at the Grimsel Test Site, aims to obtain monitoring and sampling data from an large-scale and long-term test of an engineered barrier system (EBS) consisting primarily of a bentonite buffer exposed to high temperatures (up to 200°C at the heater surface). The data complemented by laboratory testing and modelling will enhance existing databases and strengthen the understanding of buffer performance at such high temperatures. A robust assessment of the effect of such higher thermal loading on the most relevant safety functions and the resulting requirements on buffer performance would allow further optimization in the design, realization and operation of geological repositories and the management of interim storage facilities. This optimization would lead to reduced repository footprints (reduced number and/or spacing of disposal canisters and buffer dimensions) or new strategies for canister loading and, hence, requirements for cooling periods. HotBENT will contribute to assessing the effects of this higher thermal loading under realistic gradients and conditions, which cannot be obtained in the laboratory. It will allow an assessment of mineralogical, physical and chemical processes, such as smectite–illite transformation or cementation processes, which could impact the swelling, thermal and hydraulic properties and, hence, the key safety-relevant properties of the bentonite buffer. HotBENT was constructed in the period 2019–21 and has been operating at target temperatures since May 2022. The objectives, design and implementation of HotBENT, as well as the early transient phase of heating and hydration, are summarized in this paper.

This article is part of the Sustainable geological disposal and containment of radioactive waste collection available at: https://www.lyellcollection.org/topic/collections/radioactive

© 2023 Nagra - National Cooperative for the Disposal of Radioactive Waste, Switzerland. Published by The Geological Society of London for GSL and EAGE

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2023-10-18
2026-02-14

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References

  1. Alonso, J., García-Siñeriz, J.L. et al.2009. Engineering Studies and Demonstration of Repository Designs: ESDRED: Deliverable 9 of Module 4 - WP 4 (Temporary Sealing Technology). Final Technical Report FI6W-CT-2004-508851. European Commission, Brussels.
     [Google Scholar]
  2. Brennwald, M.S., Schmidt, M., Oser, J. and Kipfer, R.2016. A portable and autonomous mass spectrometric system for on-site environmental gas analysis. Environmental Science and Technology, 50, 13 455–13 463, https://doi.org/10.1021/acs.est.6b03669
     [Google Scholar]
  3. ENRESA2006. Full-scale Engineered Barriers Experiment. Updated Final Report 1994-2004. ENRESA PT Report 05-0/2006. ENRESA, Madrid.
     [Google Scholar]
  4. Fernández, A.M., Marco, J.F. et al.2022. Characterization of bentonites from the in situ ABM5 heater experiment at Äspö Hard Rock Laboratory, Sweden. Minerals, 12, 471, https://doi.org/10.3390/min12040471
     [Google Scholar]
  5. Finsterle, S.2015. Practical notes on local data-worth analysis. Water Resources Research, 51, 9904–9924, https://doi.org/10.1002/2015WR017445
     [Google Scholar]
  6. Finsterle, S.2017. HotBENT Demonstration of Data-Worth Analysis for HotBENT Monitoring. Nagra Arbeitsbericht NAB 17-055. Nagra, Wettingen, Switzerland.
     [Google Scholar]
  7. Finsterle, S., Kowalsky, M.B., Kober, F. and Vomvoris, S.2017. HotBENT – Preliminary Design Study of Phenomenological Aspects. Nagra Arbeitsbericht NAB 17-030. Nagra, Wettingen, Switzerland.
     [Google Scholar]
  8. Finsterle, S., Kowalsky, M.B., Kober, F. and Vomvoris, S.2019. HotBENT – Detailed Design Study of Phenomenological Aspects. Nagra Arbeitsbericht NAB 19-022. Nagra, Wettingen, Switzerland.
     [Google Scholar]
  9. Finsterle, S., Kober, F. and Vomvoris, S.2020. HotBENT – Modelling of Enhanced Pressurisation Options. Nagra Arbeitsbericht 20-020. Nagra, Wettingen, Switzerland.
     [Google Scholar]
  10. Fuller, W.B. and Thompson, S.E.1907. The laws of proportioning concrete. Transactions of the American Society of Civil Engineers, 59, 67–143, https://doi.org/10.1061/TACEAT.0001979
     [Google Scholar]
  11. Garitte, B., Weber, H.P. and Muller, H.R.2015. Requirements, Manufacturing and QC of the Buffer Components. Nagra Arbeitsbericht NAB 15–24 and EU Project LUCOEX, Deliverable D2.3. Nagra, Wettingen, Switzerland, https://igdtp.eu/activity/lucoex-large-underground-concept-experiments/
     [Google Scholar]
  12. Gaus, I., Wieczorek, K., Schuster, K., Garitte, B., Senger, R., Vasconcelos, R. and Mayor, J.-C.2014. EBS behaviour immediately after repository closure in a clay host rock: HE-E experiment (Mont Terri URL). Geological Society, London, Special Publications, 400, 71–91, https://doi.org/10.1144/SP400.11
     [Google Scholar]
  13. Gens, A., Sánchez, M. et al.2009. A full-scale in situ heating test for high-level nuclear waste disposal: observations, analysis and interpretation. Géotechnique, 59, 377–399, https://doi.org/10.1680/geot.2009.59.4.377
     [Google Scholar]
  14. Giroud, N., Tomonaga, Y., Wersin, P., Briggs, S., King, F., Vogt, T. and Diomidis, N.2018. On the fate of oxygen in a spent fuel emplacement drift in Opalinus Clay. Applied Geochemistry, 97, 270–278, https://doi.org/10.1016/j.apgeochem.2018.08.011
     [Google Scholar]
  15. Guimerà, J., Carrera, J. et al.1998. Hydrological Characterization and Modelling. FEBEX Report 70-UPC-M-0-1001 Rev.0. Universidad Politécnica de Madrid, Madrid.
  16. Hausmannová, L., Hanusová, I. and Dohnálková, M.2018. Summary of the Research of Czech Bentonites for Use in the Deep Geological Repository – Up to 2018. SÚRAO Technical Report 309/2018/ENG. SÚRAO, Prague.
     [Google Scholar]
  17. Kaufhold, S., Dohrmann, R., Ufer, K., Svensson, D. and Sellin, P.2021. Mineralogical analysis of bentonite from the ABM5 heater experiment at Äspö hard rock laboratory, Sweden. Minerals, 11, 669, https://doi.org/10.3390/min11070669
     [Google Scholar]
  18. Kiviranta, L. and Kumpulainen, S.2011Quality control and characterization of bentonite materials. POSIVA-WR-11-84. Posiva Oy.
     [Google Scholar]
  19. Kober, F., Vomvoris, S. and Finsterle, S.2018. HotBENT – Preliminary Design Study – Overview of Results. Nagra Arbeitsbericht NAB 17-29. Nagra, Wettingen, Switzerland.
     [Google Scholar]
  20. Kober, F., García-Siñeriz, J.L. et al.2021. FEBEX-DP Synthesis – Summary of the Full-Scale Engineered Barriers Experiment – Dismantling Project. Nagra Technischer Bericht NTB 17-01. Nagra, Wettingen, Switzerland.
     [Google Scholar]
  21. Köhler, S., Garitte, B., Weber, H.P. and Müller, H.R.2015. FE/LUCOEX: Emplacement Report. Nagra Arbeitsbericht NAB 15-27 and EU Project LUCOEX, Deliverable D2.5. Nagra, Wettingen, Switzerland.
     [Google Scholar]
  22. Lanyon, W.G., Firat Lüthi, B. and Manukyan, E.2020a. Interpretation of the First 5 Years of the FE Experiment: A THM Synthesis. Nagra Arbeitsbericht NAB 19-046. Nagra, Wettingen, Switzerland.
     [Google Scholar]
  23. Lanyon, W.G., Schneeberger, R. and Kober, F.2020b. HotBENT – Geosphere Characterisation and Instrumentation Plan. Nagra Arbeitsbericht NAB 20-19. Nagra, Wettingen, Switzerland.
     [Google Scholar]
  24. Laufek, F., Hanusová, I., Svoboda, J., Vašíček, R., Najser, J., Koubová, M. and Mašín, D.2021. Mineralogical, geochemical and geotechnical study of BCV 2017 bentonite – the initial state and the state following thermal treatment at 200°C. Minerals, 11, 871, https://doi.org/10.3390/min11080871
     [Google Scholar]
  25. Leupin, O.X., Cloet, V. et al.2016. An Assessment of the Possible Fate of Gas Generated in a Repository for Low- and Intermediate-Level Waste. Nagra Technischer Bericht NTB 16-05. Nagra, Wettingen, Switzerland.
     [Google Scholar]
  26. Müller, H.R., Garitte, B., Vogt, T., Köhler, S., Sakaki, T., Weber, H. and Cloet, V.2017. Implementation of the full-scale emplacement (FE) experiment at the Mont Terri rock laboratory. Swiss Journal of Geosciences, 110, 287–306, https://doi.org/10.1007/s00015-016-0251-2
     [Google Scholar]
  27. Nagra2019. Implementation of the Full-Scale Emplacement Experiment at Mont Terri: Design, Construction and Preliminary Results. Nagra Technical Report NTB 15-02. Nagra, Wettingen, Switzerland.
     [Google Scholar]
  28. Pruess, K., Oldenburg, C. and Moridis, G.2012. TOUGH2 User's Guide, Version 2.1. Lawrence Berkeley National Laboratory Report LBNL-43134. Lawrence Berkeley National Laboratory, Berkeley, CA.
     [Google Scholar]
  29. Rutqvist, J.2011. Status of the TOUGH–FLAC simulator and recent applications related to coupled fluid flow and crustal deformations. Computers and Geosciences, 37, 739–750, https://doi.org/10.1016/j.cageo.2010.08.006
     [Google Scholar]
  30. Sakaki, T., Lüthi, B.F. and Vogt, T.2022. Investigation of the emplacement dry density of granulated bentonite mixtures using dielectric, mass-balance and actively heated fiber-optic distributed temperature sensing methods. Geomechanics for Energy and the Environment, 32, 100329, https://doi.org/10.1016/j.gete.2022.100329
     [Google Scholar]
  31. Savage, D. and Cloet, V.2018. A Review of Cement-Clay Modelling. Nagra Arbeitsbericht NAB 18-024. Nagra, Wettingen, Switzerland.
     [Google Scholar]
  32. Schneeberger, R. and Kober, F.2022. HotBENT Project – Bentonite Materials Requirements and Production. Nagra Arbeitsbericht NAB 22-007. Nagra, Wettingen, Switzerland.
     [Google Scholar]
  33. Schneeberger, R., Kober, F., Lanyon, G.W., Spillmann, T. and Blechschmidt, I.2019. Grimsel Test Site: Revisiting the Site-Specific Geoscientific Knowledge. Nagra Technical Report NTB 19-01. Nagra, Wettingen, Switzerland.
     [Google Scholar]
  34. Schneeberger, R., Kober, F., Dorrer, R., Treuthardt, M., Baer, T. and Dorrer, A.-S.2021. HotBENT Gallery and Site Preparation Report. Nagra Arbeitsbericht NAB 20-018. Nagra, Wettingen, Switzerland.
     [Google Scholar]
  35. Schneeberger, R., Kober, F., Kaufhold, S. and Dohrmann, R.2022. HotBENT: Cementitious Materials Requirements and As-Built Characteristics. Nagra Arbeitsbericht NAB 22-006. Nagra, Wettingen, Switzerland.
     [Google Scholar]
  36. Seiphoori, A.2015. Thermo-Hydro-Mechanical Characterisation and Modelling of Wyoming Granular Bentonite. Nagra Technischer Bericht NTB 15-05. Nagra, Wettingen, Switzerland.
     [Google Scholar]
  37. Sellin, P. and Leupin, O.2013. The use of clay as an engineered barrier in radioactive waste management – a review. Clays and Clay Minerals, 61, 477–498, https://doi.org/10.1346/CCMN.2013.0610601
     [Google Scholar]
  38. Svemar, C., Johannesson, L.-E., Grahm, P., Svensson, D., Kristensson, O., Lönnqvist, M. and Nilsson, U.2016. Prototype Repository: Opening and Retrieval of Outer Section of Prototype Repository at Äspö Hard Rock Laboratory: Summary Report. SKB TR-13-22. Svensk Kärnbränslehantering (SKB), Stockholm.
     [Google Scholar]
  39. Tomonaga, Y., Giroud, N., Brennwald, M.S., Horstmann, E., Diomidis, N., Kipfer, R. and Wersin, P.2019. On-line monitoring of the gas composition in the Full-scale Emplacement experiment at Mont Terri (Switzerland). Applied Geochemistry, 100, 234–243, https://doi.org/10.1016/j.apgeochem.2018.11.015
     [Google Scholar]
  40. Wersin, P., Johnson, L.H. and McKinley, I.G.2007. Performance of the bentonite barrier at temperatures beyond 100°C: A critical review. Physics and Chemistry of the Earth, Parts A/B/C, 32, 780–788, https://doi.org/10.1016/j.pce.2006.02.051
     [Google Scholar]
  41. Zheng, L., Xu, H. and Birkholzer, J.2018. THMC Modelling in Support of an Experiment Studying the Effects of High Temperatures on Clay Buffer/Near-Field. Nagra Arbeitsbericht NAB 17 32. Nagra, Wettingen, Switzerland.
     [Google Scholar]
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The HotBENT Experiment: objectives, design, emplacement and early transient evolution
Geoenergy 1, geoenergy2023-021 (2023); https://doi.org/10.1144/geoenergy2023-021
/content/journals/10.1144/geoenergy2023-021
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