Comparison of measured and simulated concentrations of 133Xe in the shallow subsurface. (September 2018)

• Record Type: Journal Article
• Authors: Johnson, C.; Biegalski, S.R.; Lowrey, J.D.; Rockhold, M.L.; Haas, D.A.
• Is Part Of: Journal of environmental radioactivity. Volume 189(2018)
• Page Start: 207
• Page End: 212
• Publication Date: 2018-09
• Subjects: Radioactivity -- Periodicals; Radiation, Background -- Periodicals; Radioecology -- Periodicals; Radioactive pollution -- Periodicals; Environmental Pollutants -- Periodicals; Radioactive Pollutants -- Periodicals; Radioactivity -- Periodicals; Radioécologie -- Périodiques; Pollution radioactive -- Périodiques; Fond de rayonnement -- Périodiques; 539.752
• DOI: 10.1016/j.jenvrad.2018.04.010
• Languages: English
• ISSNs: 0265-931X

Abstract

Abstract: Radioactive isotopes of the noble gases xenon and argon are considered primary indicators of an underground nuclear explosion. However, high atmospheric concentrations from other anthropogenic sources may lead to an elevation in the underground levels of these gases, particularly in times of increasing atmospheric pressure. In 2014, a week long sampling campaign near Canadian Nuclear Laboratories in the Ottawa River Valley resulted in first of their kind measurements of atmospheric 133 Xe that had been pressed into the subsurface. In an effort to better understand this imprinting process, a second follow-up sampling campaign was conducted in the same location in 2016. The results of the second sampling campaign, where samples were collected at depths of 1 m and 2 m over a 14 day period and measured for their 133 Xe concentration, are presented here. Gas transport and sample concentrations were predicted using the Subsurface Transport over Multiple Phases (STOMP) simulator. These results are examined and compared to the corresponding experimental results. Highlights: Subsurface air sampled at 1.0 m and 1.9 m underground near Chalk River Laboratories. Elevated 133 Xe concentrations observed at both depths after plume passage. Samples at 1 m in sandy soil (no mitigation) may see ∼10% infiltration of atmospheric xenon. STOMP simulator used model sampling and predict sample concentrations. Simulations predict concentration within order of magnitude.