SAUNA—a system for automatic sampling, processing, and analysis of radioactive xenon

A system for automatic sampling, processing, and analysis of atmospheric radioxenon has been developed. From an air sample of about 7 m3 collected during 12 h, 0.5 cm3 of xenon is extracted, and the atmospheric activities from the four xenon isotopes 133Xe, 135Xe, 131mXe, and 133mXe are determined with a beta–gamma coincidence technique. The collection is performed using activated charcoal and molecular sieves at ambient temperature. The sample preparation and quantification are performed using preparative gas chromatography. The system was tested under routine conditions for a 5-month period, with average minimum detectable concentrations below 1 mBq/m3 for all four isotopes.