As part of an underground gas migration study, two radioactive noble gases and two stable tracer gases were injected into a nuclear explosion test chimney and allowed to migrate naturally. Soil gas samples were collected from a series of boreholes and a range of depths from the shallow subsurface (3 meters) to deeper levels (~160 meters) over a period of eleven months. These samples have provided insights into the development and evolution of the subsurface plume and constrained the relative migration rates of the radioactive and stable gas species. Analysis of the samples concluded that the stable tracer SF6 was consistently enriched in the subsurface samples relative to the radiotracer 127Xe, but the ratios of SF6 and 37Ar remained similar throughout the samples.
Revised: December 6, 2020 |
Published: November 1, 2019
Citation
Johnson C.M., C.E. Aalseth, T.R. Alexander, T.W. Bowyer, V. Chipman, A.R. Day, and S. Drellack, et al. 2019.Migration of noble gas tracers at the site of an underground nuclear explosion at the Nevada National Security Site.Journal of Environmental Radioactivity 208-209.PNNL-SA-143881.doi:10.1016/j.jenvrad.2019.106047