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Discrete-Fracture Modeling of Thermal-Hydrological Processes at Yucca Mountain and the Llnl G-Tunnel Heater Test

Published online by Cambridge University Press:  15 February 2011

John J. Nitao  and
Thomas A. Buscheck
John J. Nitao
Affiliation:
Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, CA 94551
Thomas A. Buscheck
Affiliation:
Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, CA 94551
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Abstract

An in situ heater test was performed at G-Tunnel, Nevada Nuclear Test Site, to investigate the thermal-hydrological response of unsaturated, fractured volcanic tuff under conditions similar to those at Yucca Mountain. The NUFT flow and transport code was used to model the test using discrete-fracture and equivalent-continuum approaches. Nonequilibrium fracture flow and thermal buoyant gas-phase convection were found to be the likely causes for observed lack of condensate imbibition into the matrix. The potential repository at Yucca Mountain was also modeled. Disequilibrium fracture flow is predicted to occur for less than a hundred years after emplacement followed by a period of fracture-matrix equilibrium, during which the equivalent-continuum and discrete-fracture models give almost identical results.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 412: Symposium V – Scientific Basis for Nuclear Waste Management XIX , 1995 , 747
Copyright
Copyright © Materials Research Society 1996

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References

1. Buscheck, T. A. and Nitao, J. J., “The Importance of Thermal Loading Conditions to Waste Package Performance at Yucca Mountain,” in Scientific Basis for Nuclear Waste Management XVIII, Murakami, T. and Ewing, R.C., Eds. (Materials Research Society, Pittsburg, PA, 1994).Google Scholar
2. Buscheck, T. A. and Nitao, J. J., “The Impact of Repository Heat on Hydrological Behavior at Yucca Mountain,” Proc. of the Fifth Annual Inter. Conf. High Level Radioactive Waste Management (American Nuclear Society, LaGrange Park, IL, 1994).Google Scholar
3. Nitao, J. J., “Numerical Modeling of the Thermal and Hydrological Environment around a Nuclear Waste Package using the Equivalent Continuum Approximation: Horizontal Emplacement,” Lawrence Livermore National Laboratory, Livermore, CA, UCID-21444 (1988).Google Scholar
4. Pruess, K., Wang, J. S. Y., and Tsang, Y. W., “On Thermohydrologic Conditions near High-Level Nuclear Wastes Emplaced in Partially Saturated Fractured Tuff,” Water Resour. Res. 26 (6), 1235–1248 and 1248–1261 (1990).Google Scholar
5. P Forsythe, A., “Radioactive Waste Disposal Heating Effects in Unsaturated Fractured Rock,” Numerical Heat Transfer Part A-Applications 17 (1), 29–51 (1990).Google Scholar
6. Nitao, J. J., “The NUFT Code for Modeling Nonisothermal, Multiphase, Multicomponent Flow and Transport in Porous Media,” EOS Supplement 74 (3), 313 (1993).Google Scholar
7. Ramirez, A. L. (ed.), “Prototype Engineered Barrier System Field Test (PEBSFT) Final Report,” Lawrence Livermore National Laboratory, Livermore, CA, UCRL-ID-106159 (1991).Google Scholar
8. Buscheck, T. A. and Nitao, J. J., “Estimates of the Width of the Wetting Zone Along a Fracture Subjected to an Episodic Infiltration Event in Variably Saturated, Densely Welded Tuff,” Lawrence Livermore National Laboratory, Livermore, CA, UCID-21579 (1988).Google Scholar
9. Peters, R. R., Klavetter, E. A., Hall, I. J., Blair, S. C., Hellers, P R., and Gee, G. W., “Fracture and Matrix Hydrologic Characteristics of Tuffaceous Materials from Yucca Mountain, Nye County, Nevada,” Sandia National Laboratories, Albuquerque, NM, SAND84–1471 (1984).Google Scholar
10. Buscheck, T. A. and Nitao, J. J., ”Modeling Hydrothermal Flow in Variably Saturated, ractured, Welded Tuff During the Prototype Engineered Barrier System Field Test of the Yucca Mountain Project,” Lawrence Livermore National Laboratory, Livermore, CA, UCRL-JC-106521, (1991).Google Scholar
11. Buscheck, T.A., Nitao, J.J., and Ramspott, L.D., “Localized Dryout: An Approach for Managing the Thermal-Hydrological Effects of Decay Heat at Yucca Mountain,” Proceedings Materials Research Society XIX International Symposium on the Scientific Basis for Nuclear Waste Management, Materials Research Society, Pittsburgh, PA, (1995).Google Scholar
12. Nitao, J. J., Buscheck, T. A., and Chesnut, D. A., “Implications of Episodic Nonequilibrium Fracture-Matrix Flow on Repository Performance,” Nucl. Tech. 104 (3), 385–401 (1993).Google Scholar