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Title: Geohydrology of rocks penetrated by test well USW H-6, Yucca Mountain, Nye County, Nevada

Technical Report ·
DOI:https://doi.org/10.2172/138243· OSTI ID:138243
 [1];  [2]
  1. Geological Survey, Denver, CO (United States)
  2. Fenix and Scisson, Inc., Tulsa, OK (United States)

Test well USW H-6 is one of several wells drilled in the Yucca Mountain area near the southwestern part of the Nevada Test Site for investigations related to isolation of high-level nuclear waste. This well was drilled to a depth of 1,220 meters. Rocks penetrated are predominantly ash-flow tuffs of Tertiary age, with the principal exception of dacitic(?) lave penetrated at a depth from 877 to 1,126 meters. The composite static water level was about 526 meters below the land surface; the hydraulic head increased slightly with depth. Most permeability in the saturated zone is in two fractured intervals in Crater Flat Tuff. Based on well-test data using the transitional part of a dual-porosity solution, an interval of about 15 meters in the middle part of the Bullfrog Member of the Crater Flat Tuff has a calculated transmissivity of about 140 meters squared per day, and an interval of about 11 meters in the middle part of the Tram Member of the Crater Flat Tuff has a calculated transmissivity of about 75 meters squared per day. The upper part of the Bullfrog Member has a transmissivity of about 20 meters squared per day. The maximum likely transmissivity of any rocks penetrated by the test well is about 480 meters squared per day, based on a recharge-boundary model. The remainder of the open hole had no detectable production. Matrix hydraulic conductivity ranges from less than 5 {times} 10{sup {minus}5} to 1 {times} 10{sup {minus}3} meter per day. Ground water is a sodium bicarbonate type that is typical of water from tuffaceous rock of southern Nevada. The apparent age of the water is about 14,6000 years. 29 refs., 26 figs., 5 tabs.

Research Organization:
US Geological Survey, Denver, CO (United States); Fenix and Scisson, Inc., Tulsa, OK (United States)
Sponsoring Organization:
USDOE, Washington, DC (United States)
DOE Contract Number:
AI08-78ET44802
OSTI ID:
138243
Report Number(s):
USGS/WRIR-89-4025; ON: DE92003375; TRN: 92:000262
Resource Relation:
Other Information: PBD: [1991]
Country of Publication:
United States
Language:
English