Natural and artificial nobel gas hydrologic tracers [electronic resource].
- Washington, D.C. : United States. Dept. of Energy, 1994.
Oak Ridge, Tenn. : Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy.
- Physical Description:
- 30 pages : digital, PDF file
- Additional Creators:
- Lawrence Livermore National Laboratory
United States. Department of Energy
United States. Department of Energy. Office of Scientific and Technical Information
- Noble gas isotopes provide opportunities for ground water tracing. Both naturally occurring tracers and artificially injected tracers can be used. The equilibration of water with the earth`s atmosphere records the temperature and atmospheric pressure during ground water recharge. This temperature/pressure record can be used to distinguish cold recharge from warmer recharge with a resolution of 1-2 C temperature and 500m in altitude. The radioactive decay of U and Th produce large concentrations of 4He in old ground water and this 4He signature can be useful in tracing the small addition of old water (>10,000 yr.) to young water (<100 yr.). The decay of 3H present either form nuclear testing or cosmic ray interactions leads to detectable amounts of 3He in young ground water (<50 yr.). By measuring both 3H and 3He, the mean age of the 3H in the water can be calculated. In addition to these natural tracers, isotopically enriched noble gas isotopes are readily available at low cost and can be used an non-hazardous water tracers. This inert, persistent, and harmless tracing technique can used in many situations at a cost of about one dollar per million gallons of water traced.
- Published through SciTech Connect.
- Type of Report and Period Covered Note:
- Topical; 06/01/1994 - 06/01/1994
- Funding Information:
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