Numerical simulation of gas flow through unsaturated fractured rock at Yucca Mountain, Nevada
- Nevada Univ., Las Vegas, NV (United States). Water Resources Center
Numerical analysis is used to identify the physical phenomena associated with barometrically driven gas (air and water vapor) flow through unsaturated fractured rock at Yucca Mountain, Nevada. Results from simple finite difference simulations indicate that for a fractured rock scenario, the maximum velocity of air out of an uncased 10 cm borehole is 0.002 m s{sub {minus}1}. An equivalent porous medium (EPM) model was incorporated into a multiphase, multicomponent simulator to test more complex conceptual models. Results indicate that for a typical June day, a diurnal pressure wave propagates about 160 m into the surrounding Tiva Canyon hydrogeologic unit. Dry air that enters the formation evaporates water around the borehole which reduces capillary pressure. Multiphase countercurrent flow develops in the vicinity of the hole; the gas phase flows into the formation while the liquid phase flows toward the borehole. The effect occurs within 0.5 m of the borehole. The amount of water vapor leaving the formation during 1 day is 900 cm{sup 3}. This is less than 0.1% of the total recharge into the formation, suggesting that the barometric effect may be insignificant in drying the unsaturated zone. However, gas phase velocities out of the borehole (3 m s{sup {minus}1}), indicating that observed flow rates from wells along the east flank of Yucca Mountain were able to be simulated with a barometric model.
- Research Organization:
- Nevada Nuclear Waste Project Office, Carson City, NV (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- FG08-85NV10461
- OSTI ID:
- 139152
- Report Number(s):
- NWPO-TR-014-90; ON: DE93013213; TRN: 93:016365
- Resource Relation:
- Other Information: PBD: Jan 1990
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
99 MATHEMATICS
COMPUTERS
INFORMATION SCIENCE
MANAGEMENT
LAW
MISCELLANEOUS
TUFF
GAS FLOW
HIGH-LEVEL RADIOACTIVE WASTES
UNDERGROUND DISPOSAL
YUCCA MOUNTAIN
GEOLOGIC FRACTURES
WATER VAPOR
PERMEABILITY
PRESSURE DEPENDENCE
MULTIPHASE FLOW
MATHEMATICAL MODELS
BOREHOLES
FLOW RATE
RADIONUCLIDE MIGRATION
Yucca Mountain Project