Radioxenon Atmospheric Measurements in North Las Vegas, NV

Pacific Northwest National Laboratory (PNNL) deployed the Automated Radioxenon Sampler/Analyzer (ARSA) in North Las Vegas for two weeks in February and March 2006 for the purpose of measuring the radioxenon background at a level of sensitivity much higher than previously obtained in the vicinity of the Nevada Test Site (NTS). The measurements establish what might be expected if future measurements were ever taken at the NTS itself and investigate improved methods of environmental monitoring of NTS. A second detector, the Portable Environmental Monitoring Station (PEMS), built and operated by the Desert Research Institute (DRI), was deployed in conjunction with the ARSA and contained a pressure ion chamber, aerosol collection filters, and meteorological sensors. Some of the radioxenon measurements detected 133Xe at levels up to 3 mBq/m3. This concentration of radioxenon is consistent with the observation of low levels of radioxenon emanating from distant nuclear reactors. Previous measurements in areas of high nuclear reactor concentration have shown similar results, but the western U.S., in general, does not have many nuclear reactors. Measurements of the wind direction indicate that the air carrying the radioxenon came from south of the detector and not from the NTS. Presented at the Monitoring Research Review (29th): Ground-Based Nuclear Explosion Monitoring Technologies, held in Denver, CO on 25-27 September 2007. Published in the Proceedings of the Monitoring Research Review (29th): Ground-Based Nuclear Explosion Monitoring Technologies, p779-786, 2007. Sponsored by the National Nuclear Security Administration (NNSA) and the Air Force Research Laboratory (AFRL). The original document contains color images.