Coupled Thermohydromechanical Modeling of the Full-Scale In Situ Test “Prototype Repository”
Publication: Journal of Geotechnical and Geoenvironmental Engineering
Volume 135, Issue 1
Abstract
The Prototype Repository project represents a full-scale in situ test of the Swedish concept for high level radioactive waste disposal in deep geological repositories, being conducted at the underground Äspö Hard Rock Laboratory and managed by SKB (Swedish Agency for Radioactive Waste Disposal). Instead of canisters with radioactive material, heaters installed in cylindrical containers surrounded by compacted bentonite have been used in the test. A large number of thermohydromechanical parameters for materials used in the test were carefully determined based on the latest laboratory experiments and site investigation. After comparison among six simulation models, some valuable conclusions are made about the interaction effects of six deposition holes and the effects of thermohydrogas–mechanical coupling. A three-dimensional coupled thermohydraulic model was selected for the prediction of temperature, whereas an axisymmetric two-dimensional coupled thermohydromechanical model was selected for the prediction of relative humidity and stresses for the system of heater–bentonite–near rock. Selected results of temperature, relative humidity, and total stress are presented and discussed, and the agreement between the compared variables highlights the ability of the developed models to reproduce the complex coupled processes involved in the test.
Get full access to this article
View all available purchase options and get full access to this article.
Acknowledgments
The writers wish to acknowledge the support from the European Union (Project Prototype Repository FIS5-1999-00217) and from the Spanish and Swedish Radioactive Waste Agencies (ENRESA and SKB). The support of the Spanish Ministry of Education and Science through the Program “Ramon y Cajal” is also gratefully acknowledged.
References
Alonso, E. E., Gens, A., and Josa, A. (1990). “A constitutive model for partially saturated soils.” Geotechnique, 40(3), 405–430.
Börgesson, L., Gunnarsson, D., Johannesson, L. E., and Sandén, T. (2002). “Installation of buffer, canisters, backfill and instruments in section I.” Int. Progress Rep. No. IPR-02-23, SKB, Stockholm, Sweden.
Börgesson, L., and Hernelind, J. (1999). “Coupled thermo-hydro-mechanical calculations of the water saturation phase of a KBS-3 deposition hole.” Technical Rep. No. TR-99-41, SKB, Stockholm, Sweden.
Delin, P., Sturk, R., and Stille, H. (1995). “Laboratory testing of rock.” Technical Note No. 25-95-08v, SKB, Stockholm, Sweden.
Dunnicliff, J. (1993). Geotechnical instrumentation for monitoring field performance, Wiley, New York.
Gens, A., Garcia-Molina, A. J., Olivella, S., Alonso, E. E., and Huertas, F. (1998). “Analysis of a full-scale in situ test simulating repository conditions.” Int. J. Numer. Analyt. Meth. Geomech., 22(7), 515–548.
Goudarzi, R., and Johannesson, L. E. (2006). “Sensors data report (Period 010917-061201), Report No. 16.” Int. Progress Rep. No. IPR-07-05, SKB, Stockholm, Sweden.
Gunnarsson, D., Johannesson, L., and Borgesson, L. (2001). “Backfilling of the tunnel in the prototype repository.” Int. Progress Rep. No. IPR-01-11, SKB, Stockholm, Sweden.
Hardenby, C. (2002). “Tunnel for the canister retrieval test. Geological mapping of tunnel and deposition holes.” Int. Progress Rep. No. IPR-02-49, SKB, Stockholm, Sweden.
Hoffmann, C. (2005). “Caracterización hidromecánica de mezclas de pellets de bentonita. Estudio experimental y constitutivo.” Ph.D. thesis, Technical Univ. of Catalonia, UPC, Barcelona, Spain (in Spanish).
Johannesson, L. (2002). “Manufacturing of bentonite buffer for the Prototype Repository.” Int. Progress Rep No. IPR-02-19, SKB, Stockholm, Sweden.
Klasson, H., Persson, M., and Ljunggren, C. (2001). “Rock stress measurements by overcoring at Äspö HRL, Prototype Repository: Borehole KA3579G (revised data) and K-tunnel: Borehole KK0045G01.” Int. Progress Rep. No. IPR-01-67, SKB, Stockholm, Sweden.
Ledesma, A., and Chen, G. J. (2002). “T-H-M modeling of the Prototype Repository experiment at Äspö HRL (Sweden).” Proc., Int. Conf. GeoPro2003, edited by O. Stephansson, J. A. Hudson, and L. R. Jing, eds., Royal Institute of Technology (KTH), Stockholm, Sweden.
Ledesma, A., and Chen, G. J. (2005). “T-H-M modeling of the Prototype Repository experiment: Comparison with current measurements.” Advances in understanding engineered clay barriers, E. E. Alonso and A. Ledesma, eds., Balkema, Leiden, The Netherlands, 339–346.
Lovell, M. A. (1985). “Thermal conductivities of marine sediments.” Q. J. Eng. Geol., 18(4), 437–441.
Maaranen, J., Lehtioksa, and Timonen, J. (2001). “Determination of porosity, permeability and diffusion of rock samples from Äspö HRL using the helium gas method.” Int. Progress Rep. No. IPR-02017, SKB, Stockholm, Sweden.
Mata, C. (2003). “Hydraulic behavior of bentonite based mixtures in engineered barriers: The backfill and plug test at the Äspö HRL (Sweden).” Ph.D. thesis, Technical Univ. of Catalonia, UPC, Barcelona, Spain.
Olivella, S., Carrera, J., Gens, A., and Alonso, E. E. (1994). “Non-isothermal multiphase flor of brine and gas through saline media.” Transp. Porous Media, 15(2), 271–293.
Olivella, S., Gens, A., Carrera, J., and Alonso, E. E. (1996). “Numerical formulation for a simulator (CODE_BRIGHT) for the coupled analysis of saline media.” Eng. Comput., 13(7), 87–112.
Rhen, I., and Forsmark, T. (2001). “Summary report of investigations before the operation phase.” Int. Progress Rep. No. IPR-01-65, SKB, Stockholm, Sweden.
Rutqvist, J., et al. (2001). “Thermohydromechanics of partially saturated geological media: Governing equations and formulation of four finite element codes.” Int. J. Rock Mech. Min. Sci., 38(1), 105–127.
van Genuchten, R. (1980). “A closed-form equation for predicting the hydraulic conductivity of unsaturated soils.” Soil Sci. Soc. Am. J., 44, 892–898.
Villar, M. V. (2005). “MX-80 bentonite thermo-hydro-mechanical characterization performed at CIEMAT in the context of the Prototype project.” Technical Rep. No. 1053, Ciemat, Madrid, Spain.
Information & Authors
Information
Published In
Copyright
© 2009 ASCE.
History
Received: Aug 14, 2006
Accepted: May 7, 2008
Published online: Jan 1, 2009
Published in print: Jan 2009
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.