Aufbau einer anordnung zur probennahme und messung von krypton-85 in luft und messergebnisse

A method for sampling and measurement of krypton 85 in the atmosphere was developed based on the technique described by Stockburger et al. 1, 2]. The air is pumped through charcoal cooled with liquid nitrogen. Krypton is obtained from the air sample by fractionated desorption followed by gaschromatographic separation with simultaneous determination of the krypton volume. The ⁸⁵Kr activity is measured in a proportional counter. The calibration was carried out with an accuracy of ±5.2% (significance level 95%).

The ⁸⁵Kr activity concentration of a sample collected from 30 April to 3 May 1986 (Chernobyl accident) in Neuherberg near Munich was more than twice of the mean value of 1 Bq/m³ air.

Subsequently a continuous 14-day sampling along the north-south direction at three locations in Bavaria was carried out. From 1986 to 1991 a mean linear increase of the atmospheric ⁸⁵Kr activity concentration of 0.037 ± 0.010 Bq/m³ per year (significance level 95%) was determined.