Speaker
Description
The nuclear and radiopharmaceutical industrial emissions of the four CTBT-relevant radioxenon isotopes are detected by the IMS along with possible treaty violations. To better understand the source terms of these background emissions, a joint project between Health Canada (HC), Australian Nuclear Science and Technology Organisation (ANSTO), Pacific Northwest National Lab (PNNL) and Chalk River Laboratory (CRL) to install real-time detection systems to monitor 135Xe, 133Xe, 131mXe and 133mXe at ANSTO and CRL 99Mo production facility stacks as well as the CANDU (CANada Deuterium Uranium) primary coolant monitoring system at CRL. At each site, high-resolution gamma spectra were collected from a bypass stack feed or CANDU primary coolant system as it passed through a sampling cell. HC also conducted radioxenon atmospheric monitoring approximately 200 km from CRL. The isotopic signatures of the various radioxenon species can be determined from different source terms. Comparison of 133mXe and 133Xe activity ratios showed distinct differences between the closed CANDU primary coolant system and radiopharmaceutical production releases. The multiple isotopic activity ratios were distributed in different domains (civilian/nuclear test). Most measurements were found to be civilian in nature. There were some situations where isotopic ratios from 99Mo production emissions fell within the nuclear test domain.
