Performance characterization of the Radionuclide Aerosol Sampler/Analyzer air sampler during a high-activity release event

The performance of the Radionuclide Aerosol Sampler/Analyzer (RASA) under high-activity conditions has been evaluated to maintain and protect operations International Monitoring System (IMS) radionuclide stations. Station measurements following Fukushima Daichi accident 11 March 2011 have combined with laboratory understand how quality made using RASA High-Purity Germanium (HPGe) gamma-spectrometer are impacted by increased sample activity detector dead-time. Detector saturation identified occur at a count rate 175,000 counts s−1, which level there significant impacts live-time resolution in addition system contamination risk. To safeguard against these effects, dead-time limit 16.6% is proposed that could be maintained monitoring collecting on filter Cadmium Zinc Telluride (CZT) installed into particulate collection area RASA. This would ensure IMS technical specifications for measurement time (> 20 h) (2.5 keV 1332 keV) met. CZT dynamically control air flow beneath HPGe threshold also provide useful CTBT verification purposes dose assessments.