The application of borehole logging to characterize the hydrogeology of the Faultless site, Central Nevada Test Area
The Central Nevada Test Area was the site of the Faultless underground nuclear test that could be a source of radionuclide contamination to aquifers in Hot Creek Valley, Nevada. Field studies in 1992 and 1993 have used hydrologic logging and water sampling to determine the adequacy of the current groundwater monitoring network and the status of water-level recovery to pre-shot levels in the nuclear chimney. The field studies have determined that there is a possibility for contaminant migration away from the Faultless event though the pre-event water level has not been attained, while new data raise questions about the ability of the current monitoring network to detect migration. Hydrologic logs from the postshot hole (drilled into the chimney created by the nuclear detonation) reveal inflow around 485 m below land surface. The physical and chemical characteristics of the inflow water indicate that its source is much deeper in the chimney, perhaps driven upward in a convection cell generated by heat near the nuclear cavity. Logging and sampling at monitoring wells HTH-1 and HTH-2 revealed that the completion of HTH-1 may be responsible for its elevated water level (as compared to pre-nuclear test levels) and may have also created a local mound in the water table in the alluvium that accounts for higher post-test water levels at HTH-2. This mound would serve to divert flow around the monitoring wells, so that only migration of contaminants through the underlying, higher pressure, volcanic units is currently monitored. A hydraulic high found in an abandoned hole located between the nuclear chimney and the monitoring wells further reduces the likelihood of HTH-1 or HTH-2 intercepting contaminant migration.
- Research Organization:
- Nevada Univ., Las Vegas, NV (United States). Water Resources Center
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC08-90NV10845
- OSTI ID:
- 10106453
- Report Number(s):
- DOE/NV/10845-35; ON: DE95003833; IN: DRI 45119; TRN: AHC29505%%1
- Resource Relation:
- Other Information: PBD: Aug 1994
- Country of Publication:
- United States
- Language:
- English
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Field investigation at the Faultless Site Central Nevada Test Area
Field investigation at the Faultless Site Central Nevada Test Area
Related Subjects
45 MILITARY TECHNOLOGY, WEAPONRY, AND NATIONAL DEFENSE
NEVADA TEST SITE
RADIONUCLIDE MIGRATION
HYDROLOGY
SAMPLERS
ACCURACY
AQUIFERS
NUCLEAR EXPLOSIONS
UNDERGROUND EXPLOSIONS
ENVIRONMENTAL EFFECTS
WELL LOGGING EQUIPMENT
WATER TABLES
LIQUID FLOW
GROUND WATER
WATER POLLUTION MONITORS
WATER WELLS
CHEMICAL LOGGING
TEMPERATURE LOGGING
EXPERIMENTAL DATA
540230
450200
RADIOACTIVE MATERIALS MONITORING AND TRANSPORT
NUCLEAR EXPLOSIONS AND EXPLOSIVES