title: Isotopic noble gas signatures released from medical isotope production facilities--simulations and measurements.
abstract: Radioxenon isotopes play a major role in confirming whether or not an underground explosion was nuclear in nature. It is then of key importance to understand the sources of environmental radioxenon to be able to distinguish civil sources from those of a nuclear explosion. Based on several years of measurements, combined with advanced atmospheric transport model results, it was recently shown that the main source of radioxenon observations are strong and regular batch releases from a very limited number of medical isotope production facilities. This paper reviews production processes in different medical isotope facilities during which radioxenon is produced. Radioxenon activity concentrations and isotopic compositions are calculated for six large facilities. The results are compared with calculated signals from nuclear explosions. Further, the outcome is compared and found to be consistent with radioxenon measurements recently performed in and around three of these facilities. Some anomalies in measurements in which (131m)Xe was detected were found and a possible explanation is proposed. It was also calculated that the dose rate of the releases is well below regulatory values. Based on these results, it should be possible to better understand, interpret and verify signals measured in the noble gas measurement systems in the International Monitoring of the Comprehensive Nuclear-Test-Ban Treaty.
authors.affiliation: Vienna University of Technology, Atomic Institute of the Austrian Universities, Stadionallee 2, Vienna, Austria. paul.saey@ati.ac.at
authors.forename: Paul R J
authors.initials: PR
authors.lastname: Saey
authors.forename: Theodore W
authors.initials: TW
authors.lastname: Bowyer
authors.forename: Anders
authors.initials: A
authors.lastname: Ringbom
mesh_terms: D000396:Air Pollutants, Radioactive / Q000032:analysis*; D003198:Computer Simulation; D008956:Models, Chemical; D011829:Radiation Dosage; D011834:Radiation Monitoring / Q000379:methods*; D019275:Radiopharmaceuticals / Q000032:analysis* / Q000138:chemical synthesis*; D014980:Xenon Radioisotopes / Q000032:analysis* / Q000737:chemistry*
chemical_list: D000396:Air Pollutants, Radioactive; D019275:Radiopharmaceuticals; D014980:Xenon Radioisotopes