Pore-water isotopic compositions and unsaturated-zone flow, Yucca Mountain, Nevada

Conference · Sun Apr 29 00:00:00 EDT 2001

OSTI ID:794111

Yang, In C ^[1]

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1. USGS, Denver, CO

Isotopic compositions of core-water samples from boreholes USW SD-6 and USW WT-24 indicate that recent water has been introduced at depth. Tritium, carbon, oxygen, and deuterium isotopic compositions all support younger water at depth in the two boreholes. Peaks in tritium concentrations in pore-water samples, indicating younger water than the other samples, observed near the basal vitrophyre of the Topopah Spring Tuff and at the bottom of the CHF and the top of the PP in both boreholes SD-6 and WT-24. Larger {sup 14}C activities in two pore-water samples from WT-24 at the bottom of the CHF and the top of the PP indicate younger water than in other samples from WT-24. More positive {delta}{sup 18}O and {delta}D values indicate younger water in samples of pore water at the bottom of the CHF in boreholes SD-6 and WT-24. The isotopic compositions indicating younger water at depth in boreholes SD-6 and WT-24 occur at the basal vitrophyre zone of the Topopah Spring Tuff and the bottom of the CHF/upper part of the PP, probably from lateral preferential flow through connected fractures (fast-flow paths). The source of the young water at borehole WT-24 probably was recharge from The Prow to the north, which then flowed laterally southward through the highly fractured TSw. The source of the young water at borehole SD-6 probably was water flow from the Solitario Canyon fault to the west, which then flowed laterally through the TSw and CHF.

• Research Organization: U.S. Geological Survey, Denver, CO (US)
• Sponsoring Organization: US Department of Energy (US)
• DOE Contract Number: AI08-97NV12033
• OSTI ID: 794111
• Country of Publication: United States
• Language: English

Related Subjects

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES
CARBON ISOTOPES
DEUTERIUM
GEOLOGIC FRACTURES
HIGH-LEVEL RADIOACTIVE WASTES
INTERSTITIAL WATER
ISOTOPE RATIO
ISOTOPIC
OXYGEN ISOTOPES
PORE-WATER
RADIOACTIVE WASTE FACILITIES
SITE CHARACTERIZATION
TRITIUM
TUFF
UNSATURATED
YUCCA MOUNTAIN