A Proposal to Use Chlorine-36 for Monitoring the Movement of Radionuclides from Nuclear Explosions


  • Fred M. Phillips,

    1. Fred Phillips is associate professor of Hydrology at New Mexico Tech in Socorro (Geoscience Department, New Mexico Tech, Socorro, NM 87801). He obtained bachelor's degrees in earth science and history from the University of California at Santa Cruz in 1976, and M.S. and Ph.D. degrees in hydrology from the University of Arizona in 1979 and 1981. He has performed research on radiometric dating of ground water, application of stable isotopes to Quaternary paleohydrology, surface exposure dating using the accumulation of cosmogenic radionuclides, and geological controls on solute transport in ground water. In 1988 he was awarded the Clarke Medal by the Geochemical Society in recognition of his work in developing hydrogeologic applications of 36C1.
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  • Stanley N. Davis,

    1. Dr. Stanley N. Davis is a professor of hydrology in the Department of Hydrology and Water Resources, University of Arizona (Tucson, AZ 85721). His research interests include ground water contamination, natural trace radionuclides in ground water, isolation of radioactive wastes, natural ground water tracers, and the hydrogeology of volcanic rocks. In 1989 he received the O.E. Meinzer Award from the Geological Society of America for his contributions to hydrogeology.
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  • Peter Kubik

    1. Peter W. Kubik (Nuclear Structure Research Laboratory, University of Rochester, Rochester, NY 14627) received his Ph.D. from the Technical University of Munich. He has been with the Nuclear Structure Research Laboratory since 1985 and is now in charge of its accelerator mass spectrometry program.
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Chlorine-36 has been produced in large amounts by hundreds of nuclear explosions on the Nevada Test Site as well as 12 off-site explosions at eight locations in five states. Continued monitoring of the redistribution of radionuclides by subsurface water is of concern in most of the areas affected by the detonations. Chlorine-36 has the following advantages as a built-in tracer for this redistribution: its mobility is equal to or greater than water, its long half-life assures its continued usefulness over long periods, collection and storage of samples is simple, it is not subject to vapor transport at ordinary temperatures, its natural background is very low, and it does not form insoluble precipitates. Chlorine-36 from the Gnome event near Carlsbad, New Mexico, illustrates how 36C1 can be used to help study the redistribution of radionuclides in the soil profile. Chlorine-36 is also potentially useful as a tracer to study movement of contaminants around large nuclear reactor complexes and near respositories for radioactive waste.