Injection and sampling of 133Xe in shallow boreholes in alluvium

We present an overview of a small-scale tracer migration experiment that was carried out in July 2018 at the Nevada National Security Site. This experiment involved the injection of 133Xe into the bottom of a shallow borehole with multiple sampling intervals. Sampling was then conducted in the injection borehole and in a second borehole located 17 m from the injection site. A simple system for measurement of the 133Xe activity in whole air was utilized onsite. Though many samples were well below MDC, cross-hole tracer transport was observed. Along with experimental results, additional insights gained from numerical modeling are presented.