Photoneutron logging system for direct uranium ore-grade determination [electronic resource].
- Los Alamos, N.M. : Los Alamos National Laboratory, 1982.
Oak Ridge, Tenn. : Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy.
- Physical Description:
- Pages: 38 : digital, PDF file
- Additional Creators:
- Los Alamos National Laboratory
United States. Department of Energy. Office of Scientific and Technical Information
- A prototype photoneutron probe for direct uranium assay in exploratory boreholes has been built and field tested. An approx. 10-Ci /sup 124/Sb gamma-ray source together with a beryllium converter is used to produce neutrons that diffuse into the surrounding formation and cause fissions in any /sup 235/U present. The fission neutrons that return to the probe are energy analyzed and counted by a high-pressure helium detector, thus indicating the concentration of uranium. The response of the probe was measured in concrete models at the US Department of Energy (Grand Junction, Colorado) calibration facility and found to be approx. 35 counts/s for an 1% U/sub 3/O/sub 8/ concentration in an 11.4-cm-diam water-filled borehole (4.5 in.). The response is linear up to a concentration of at least 0.25% by weight U/sub 3/O/sub 8/. Effects resulting from changes in formation density, porosity, and neutron absorber content were also quantified, as well as the tool response as a function of borehole diameter and fluid. A logging vehicle was outfitted, and the photoneutron-based logging system was field tested at an exploration site near Canon City, Colorado. Logging data obtained in several open holes at this site are presented and compared to core chemical analyses and results obtained in the same holes using other logging methods. In about 1 month of field testing, the photoneutron-based uranium exploration system has proved to be simple to use and very reliable. 22 figures, 12 tables.
- Published through SciTech Connect.
Baker, M.P.; Marks, T.
- Funding Information:
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