Changes in radioxenon observations in Canada and Europe during medical isotope production facility shut down in 2008

Radioxenon concentration data collected at International Noble Gas Experiment (INGE) monitoring sites in the Northern Hemisphere are demonstrably impacted by emissions from medical isotope (MI) production facilities at Chalk River (CRL), Ontario and Fleurus, Belgium [Saey, J Environ Radioact 100(5):396–406, 2009]. Temporary cessation at these European MI facilities in the latter half of 2008 allowed an opportunity to assess the relative impact of distant MI facilities at INGE monitoring stations. In particular, the concentration distributions at the measurement sites and calculated sensitivities to the putative emission locations through atmospheric transport modelling (ATM) of meteorological Source Receptor Sensitivity (SRS) computations were used to study MI impacts.