Transport properties of Topopah Spring tuff
Electrical resistivity, ultrasonic P-waves velocity, and water permeability were measured simultaneously on both intact and fractured Topopah Spring tuff samples at a confining pressure of 5.0 MPa, pore pressures to 2.5 MPa, and temperatures to 140{sup 0}C. The tested samples were subjected to three dehydration and rehydration cycles. The dehydrations were accomplished at a temperature of 140{sup 0}C, and the rehydrations were accomplished at various combinations of temperature and pore pressures so that the wetting fluid was either liquid water, steam or both. The electrical resistivity measurements indicate that for the intact sample, the drying and resaturation took place fairly uniformly throughout the sample. On the other hand, for the fractured sample, the drying and resaturation was spatially quite nonuniform. When samples had been subjected to 5 MPa of confining pressure and 140{sup 0}C for several weeks, a gradual monotonic drift in resistivity was measured (decreasing resistivity when dry; increasing resistivity when wet). This may be the result of either minerological changes or grain boundary movement. In any case, the phenomenon may have important consequences on long term repository performance, and should be studied further. The permeability of the intact sample was independent of temperature, dehydration and rehydration cycles, and time. The permeability of the fractured sample, initially dominated by the fracture, decreased by about one order of magnitude after each dehydration and rehydration cycle. 11 references, 12 figures, 3 tables.
- Research Organization:
- Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
- DOE Contract Number:
- W-7405-ENG-48
- OSTI ID:
- 59338
- Report Number(s):
- UCRL-53602; ON: DE85010448
- Resource Relation:
- Other Information: PBD: Oct 1984
- Country of Publication:
- United States
- Language:
- English
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05 NUCLEAR FUELS
54 ENVIRONMENTAL SCIENCES
TUFF
PERMEABILITY
POROSITY
ELECTRIC CONDUCTIVITY
NEVADA TEST SITE
YUCCA MOUNTAIN
ROCK-FLUID INTERACTIONS
GROUND WATER
LEACHING
RADIONUCLIDE MIGRATION
GEOLOGIC FISSURES
TEMPERATURE RANGE 0273-0400 K
DEHYDRATION
WATER SATURATION
P WAVES
RESISTIVITY SURVEYS
RADIOACTIVE WASTE DISPOSAL
EXPERIMENTAL DATA
UNDERGROUND DISPOSAL
Yucca Mountain Project