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Modeling of the Thermohydrodynamic and Reactive Behavior of Compacted Clay for High-Level Radionuclide Waste-Management Systems

Published online by Cambridge University Press:  01 January 2024

Ricardo Juncosa ,
Vicente Navarro ,
Jordi Delgado  and
Ana Vázquez
Ricardo Juncosa*
Affiliation:
Civil Engineering School, University of La Coruña, Campus de Elviña s/n, 15192, A Coruña, Spain
Vicente Navarro
Affiliation:
Civil Engineering School, University of Castilla-La Mancha, Avda. Camilo José Cela s/n, 13071, Ciudad Real, Spain
Jordi Delgado
Affiliation:
Civil Engineering School, University of La Coruña, Campus de Elviña s/n, 15192, A Coruña, Spain
Ana Vázquez
Affiliation:
Civil Engineering School, University of La Coruña, Campus de Elviña s/n, 15192, A Coruña, Spain
*
* E-mail address of corresponding author: [email protected]
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Abstract

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Bentonite is often proposed as an engineered-buffer material in high-level radionuclide waste-management systems. For effective design of the barrier that will provide protection over the long time periods required, the physical/thermal/chemical processes taking place in the barrier material must be understood thoroughly. These processes, which interact, include the flow of water and gas, the flow of heat, and the transport and reaction of chemical constituents. The purpose of this study was to better understand the processes that occurred in a small-scale experiment within a confined bentonite space. A conceptual and mathematical model (FADES-CHEM) was built in order to simulate the results of an experiment conducted in 2000, and thereby to gain a better understanding of the controlling processes. In that experiment, a block of compacted bentonite was placed in an air-tight cell and subjected, for 6 months, to simultaneous heating and hydration from opposite sides. The bentonite block was then sliced into five sections each of which was then analyzed in order to obtain a series of physicochemical parameters illustrating the changes that had occurred. Before modeling, the chemical composition of the bentonite pore waters was restored in order to account for different processes such as gas outgassing and cell cooling. Modeling indicated that gas-pressure build up was a relevant process when computing the saturation of bentonite, and the computations in the present study suggested that evaporation/condensation processes played a crucial role in the final distribution of the water content. Gas pressure and evaporation/ condensation also affected the geochemical system, and the numerical model developed gives results that were consistent with the experimental values and trends observed. The model reproduced the results obtained and enable use at the repository scale and over longer time frames, provided that adequate data are available.

Keywords

BentoniteContaminant TransportMultiphase FlowNumerical ModelingReactive Transport
Type
Article
Information
Clays and Clay Minerals , Volume 58 , Issue 4 , August 2010 , pp. 486 - 500
Copyright
Copyright © The Clay Minerals Society 2010

References

Allison, J.D. Brown, D.S. and Novo-Gradac, K.J., 1991 MINTEQA2/PRODEFA2, a geochemical assessment model for environmental systems .Google Scholar
Bear, J., 1972 Dynamics of Fluids in Porous Media New York American Elsevier.Google Scholar
Bethke, C.M., 1994 The Geochemist ‘s Workbench™, version 2.0, A user’s guide to Rxn, Act2, Tact, React, and Gtplot University of Illinois, USA Hydrogeology Program.Google Scholar
Celia, M.A. Bouloutas, E.T. and Zarba, R.L., 1990 A general mass-conservative numerical solution for the unsaturated flow equation Water Resources Research 26 1483–1496 10.1029/WR026i007p01483.CrossRefGoogle Scholar
Cheng, H.P. and Yeh, G.T., 1998 Development of a three-dimensional model of subsurface flow, heat transfer, and reactive chemical transport: 3DHYDROGEOCHEM Journal of Contaminant Hydrology 34 47–83 10.1016/S0169-7722(98)00084-9.CrossRefGoogle Scholar
Chillingarian, G.V. and Riecke, H.H., 1968 Data on consolidation of fine grained sediments Journal of Sedimentary Petrology 33 919–930.Google Scholar
Cuevas, J. Villar, M.V. Fernandez, A.M. Gomez, P. and Martín, P.L., 1997 Pore waters extracted from compacted bentonite subjected to simultaneous heating and hydration Applied Geochemistry 12 473–481 10.1016/S0883-2927(97)00024-3.CrossRefGoogle Scholar
EC, 2000 Full-scale engineered barriers experiment for a deep geological repository for high level radioactive waste in crystalline host rock (FEBEX project) .Google Scholar
EC, 2003 Engineered Barrier Systems and the Safety of Deep Geological Repositories. State-of-the-art Report .Google Scholar
Edlefsen, N.E. and Anderson, A.B.C., 1943 Thermodynamics of soil moisture Hilgardia 15 31–298 10.3733/hilg.v15n02p031.CrossRefGoogle Scholar
ENRESA, 2004 FEBEX II Project THG laboratory experiment .Google Scholar
Fernandez, A.M. Cuevas, J. Rivas, P., Hart, K.P. and Lumpkin, G.R., 2000 Pore water chemistry of the FEBEX bentonite Scientific Basis for Nuclear Waste Management XXIV 577–588.CrossRefGoogle Scholar
Fernandez, A.M. Baeyens, B. Bradbury, M. and Rivas, P., 2004 Analysis of the pore water chemical composition of a Spanish compacted bentonite used in an engineered barrier Physics and Chemistry of the Earth 29 105–118 10.1016/j.pce.2003.12.001.CrossRefGoogle Scholar
Gens, A. García-Molina, A.J. Olivella, S. Alonso, E.E. and Huertas, F., 1998 Analysis of a full scale in situ test simulating repository conditions International Journal for Numerical and Analytical Methods in Geomechanics 22 515–548 10.1002/(SICI)1096-9853(199807)22:7<515::AID-NAG926>3.0.CO;2-8.3.0.CO;2-8>CrossRefGoogle Scholar
Huertas, F.J. Carretero, P. Delgado, J. Linares, J. and Samper, J., 2001 An experimental study on the ion-exchange behavior of the smectite of Cabo de Gata (Almería, Spain): FEBEX bentonite Journal of Colloids and Interface Science 239 409–416 10.1006/jcis.2001.7605.CrossRefGoogle Scholar
Johnson, J.W. Oelkers, E.H. and Helgeson, H.C., 1992 SUPCRT92: A software package for calculating the standard molal thermodynamic properties of minerals, gases, aqueous species and reaction from 1 to 5000 bar and 0 to 1000ºC Computer & Geosciences 18 899–947 10.1016/0098-3004(92)90029-Q.CrossRefGoogle Scholar
Juncosa, R., 2001 Modelos deflujo multifásico no isotermo y de transporte reactivo multicomponente en medios porosos .CrossRefGoogle Scholar
Juncosa, R. Samper, J. Navarro, V. Delgado, J. Carretero, P., Munoz-Carpena, R. Ritter, A. Tascon, C., 1999 Modelos de flujo multifásico no isotermo con reacciones químicas Estudios de la Zona No Saturada Tenerife, Spain ICIA 169–174.Google Scholar
Juncosa, R. Samper, J. Vazquez, A. and Montenegro, L., 2003 Modelos de flujo multifásico no isotermo y transporte reactivo multicomponente en medios porosos: 2. Aplicacion a bentonitas compactadas Ingeniería del Agua 10 37–48 10.4995/ia.2003.2575.CrossRefGoogle Scholar
Juncosa, R Xu T and Pruess, K., 2001 A comparison of results obtained with two subsurface non-isothermal multiphase reactive transport simulators, FADES-CORE and TOUGHREACT California, USA Ernest Orlando Lawrence Berkeley National Laboratory, Earth Sciences Division 10.2172/783485.CrossRefGoogle Scholar
KASAM, 1995 Nuclear Waste and the Environment. Proceedings of an International Seminar on Environmental Impact Assessment and its role in connection with the final disposal of nuclear waste Luleå, Sweden The National Council for Nuclear Waste (KASAM).Google Scholar
Kaufhold, S. Dohrmann, R. Koch, D. and Houben, G., 2008 The pH of aqueous bentonite suspensions Clays and Clay Minerals 56 338–343 10.1346/CCMN.2008.0560304.CrossRefGoogle Scholar
Krumhansl, J.L., 1986 Observations regarding the stability of benonite backfill in a high-level (HLW) repository in rock salt USA Sandia National Laboratory, Department of Energy, Alburquerque, NM.Google Scholar
Li, Y. and Gregory, S., 1974 Diffusion of ions in sea water and in deep-sea sediments Geochimica et Cosmochimica Acta 38 703–714 10.1016/0016-7037(74)90145-8.Google Scholar
Lichtner, P.C., Steefel, C.I., and Oelkers, E.H. 1996(editors) () Reactive Transport in Porous Media. Reviews in Mineralogy, 34. Mineralogical Society of America, Washington, D.C., 438 pp.CrossRefGoogle Scholar
Lide, D.R., 1997 Handbook of Chemistry and Physics Boca Raton, Florida, USA The Chemical Rubber Company, CRC Press.Google Scholar
Manheim, F.T., 1974 Comparative studies on extraction of sediment interstitial waters: Discussion and comment on the current state of interstitial water studies Clays and Clay Minerals 22 337–343 10.1346/CCMN.1974.0220404.CrossRefGoogle Scholar
Mayer, K.U. Frind, E.O. and Blowes, D.W., 2002 Multicomponent reactive transport modeling in variably saturated porous media using generalized formulation for kinetically controlled reactions Water Resources Research 38 1174 13–1.CrossRefGoogle Scholar
Mayhew, Y.R. and Rogers, G.F.C., 1976 Thermodynamic and Transport Properties of Fluids Oxford, UK Blackwell.Google Scholar
Millero, F.J., 1982 The effect of pressure on the solubility of minerals in water and sea water Geochimica et Cosmochimica Acta 46 11–22 10.1016/0016-7037(82)90286-1.CrossRefGoogle Scholar
Milly, P.C.D., 1985 A mass-conservative procedure for time-stepping in models of unsaturated flow Advances in Water Resources 8 32–36 10.1016/0309-1708(85)90078-8.CrossRefGoogle Scholar
Moore, D.M. and Reynolds, RC Jr., 1997 X-ray Diffraction and the Identification and Analysis of Clay Minerals New York Oxford University Press.Google Scholar
Muurinen, A., 2001 Development and testing of analysis methods for bentonite pore water .Google Scholar
Navarro, V., 1997 Modelo de comportamiento mecánico e hidráulico de suelos no saturados en condiciones no isotermas Spain Polytechnical University of Catalonia.Google Scholar
Navarro, V. and Alonso, E.E., 2000 Modeling swelling soils for disposal barriers Computers and Geotechnics 27 19–43 10.1016/S0266-352X(00)00002-1.CrossRefGoogle Scholar
Nguyen, T.S. Selvadurai, A.P.S. and Armand, G., 2005 Modelling the FEBEX THM experiment using a state surface approach International Journal of Rocks Mechanics and Mining Sciences 42 639–651 10.1016/j.ijrmms.2005.03.005.CrossRefGoogle Scholar
Nitao, J.J., 1998 Reference manual for the NUFT flow and transport code, version 2.0 California, USA Lawrence Livermore National Laboratory Report UCRL-MA-130651.Google Scholar
NEA, 1995 The environmental and ethical basis of geological disposal of long-lived radioactive wastes. A collective opinion of the Radioactive Waste Management Committee of the OECD Nuclear Energy Agency .Google Scholar
NEA, 2000 Pore water extraction from argillaceous rocks for geochemical characterisation Paris OECD Nuclear Energy.Google Scholar
Olivella, S., 1995 Non-isothermal multiphase flow of brine and gas through saline media Spain Polytechnical University of Catalonia.Google Scholar
Panday, S. and Corapcioglu, M.Y., 1989 Reservoir transport equations by compositional approach Transport in Porous Media 4 369–393 10.1007/BF00165780.CrossRefGoogle Scholar
Parkhurst, D.L., 1995 PHREEQC, a computer model for speciation, reaction-path, advective transport and inverse geochemical calculations .Google Scholar
Pearson, F.J. Fisher, D.W. and Plummer, N.L., 1978 Correction of ground-water chemistry and carbon isotopic composition for effects of CO2 outgassing Geochimica et Cosmochimica Acta 42 1799–1807 10.1016/0016-7037(78)90235-1.CrossRefGoogle Scholar
Pollock, D.W., 1986 Simulation of fluid flow and energy transport processes associated with high-level radioactive waste disposal in unsaturated alluvium Water Resources Research 22 765–775 10.1029/WR022i005p00765.CrossRefGoogle Scholar
Pruess, K., 1987 TOUGH User’s Guide 10.2172/5830643.CrossRefGoogle Scholar
Pruess, K., 1991 TOUGH2 A general-purpose numerical simulator for multiphase fluid and heat flow Berkeley, California, USA Earth Sciences Division, LWL 10.2172/5212064.CrossRefGoogle Scholar
Pusch, R. and Karnland, O., 1986 Aspects of the physical state of smectite-adsorbed water .Google Scholar
Pusch, R. Muurinen, A. Lehikoinen, J. Bors, J. and Eriksen, T., 1999 Microstructural and chemical parameters of bentonite as determinants of waste isolation efficiency .Google Scholar
Scanlon, B.R. Nicot, J.P. Massmann, J.W. and Warwick, A.W., 2002 Soil gas movement in unsaturated systems Soil Physics Companion Boca Raton, Florida, USA CRC Press 297–341.Google Scholar
Simunek, J. and Suarez, D., 1994 Two-dimensional transport model for variably saturated porous media with major ion chemistry Water Resources Research 30 1115–1133 10.1029/93WR03347.CrossRefGoogle Scholar
Steefel, C.I. MacQuarrie, K.T.B., Lichtner, P. Steefel, C.I. Oelkers, E.H., 1996 Approaches to modelling of reactive transport in porous media Reactive Transport in Porous Media Washington, D.C Mineralogical Society of America 83–129 10.1515/9781501509797-005.CrossRefGoogle Scholar
Stumm, W. and Morgan, J.J., 1981 Aquatic Chemistry 2nd New York Wiley-Interscience.Google Scholar
Thomas, H.R. and He, Y., 1997 A coupled heat-moisture transfer theory for deformable unsaturated soil and its algorithmic implementation International Journal for Numerical Methods in Engineering 40 3421–3441 10.1002/(SICI)1097-0207(19970930)40:18<3421::AID-NME220>3.0.CO;2-C.3.0.CO;2-C>CrossRefGoogle Scholar
Van Genuchten, M.T., 1980 A closed-form equation for predicting the hydraulic conductivity of unsaturated soils Soil Science Society of America Journal 44 892–898 10.2136/sssaj1980.03615995004400050002x.CrossRefGoogle Scholar
Villar, M.V. and Lloret, A., 2004 Influence of temperature on the hydromechanical behavior of a compacted bentonite Applied Clay Science 26 337–350 10.1016/j.clay.2003.12.026.CrossRefGoogle Scholar
Villar, M.V. Cuevas, J. Martín, P.L. Campos, R. and Fernandez, A.M., 1995 Thermo-hydro-mechanical characterization of the Spanish reference clay material for engineered barrier for granite and clay HLW repository: laboratory and small mock-up testing .Google Scholar
Villar, M.V. Cuevas, J. and Martín, P.L., 1996 Effects of heater/water flow interaction on compacted bentonite: Preliminary results Engineering Geology 41 257–267 10.1016/0013-7952(95)00037-2.CrossRefGoogle Scholar
Villar, M.V. Martín, P.L. and Barcala, J.M., 2005 Modification of physical, mechanical and hydraulic properties of bentonite by thermo-hydraulic gradients Engineering Geology 81 284–297 10.1016/j.enggeo.2005.06.012.CrossRefGoogle Scholar
Wang, H. Liang, D. Ewing, R.E. Lyons, S.L. and Quin, G., 2003 An improved numerical simulator for different types of flows in porous media Numerical Methods for Partial Differential Equations 19 343–362 10.1002/num.10045.CrossRefGoogle Scholar
White, A.F., 1995 Multiphase non-isothermal transport of systems of reactive chemicals Water Resources Research 31 1761–1772 10.1029/95WR00576.CrossRefGoogle Scholar
Wolery, T.J., 1992 EQ3/EQ6, a software package for geochemical modelling of aqueous systems, package overview and installation guide California, USA Lawrence Livermore Nacional Laboratory Report UCRL-MA-110662(1) 10.2172/138894.CrossRefGoogle Scholar
Xu, T., 1996 Modelización del transporte no isotermo de sistemas de solutos reactivos a través de medios porosos parcialmente saturados Spain University of A Coruna.Google Scholar
Xu, T. and Pruess, K., 1998 Coupled modeling of non-isothermal multi-phase flow, solute transport and reactive chemistry in porous and fractured media: 1. Model development and validation California, USA Ernest Orlando Lawrence Berkeley National Laboratory, Earth Sciences Division.Google Scholar
Zilberbrand, M., 1999 On equilibrium constants for aqueous geochemical reactions in water unsaturated soils and sediments Aquatic Geochemistry 5 195–206 10.1023/A:1009695510370.CrossRefGoogle Scholar