Heidelberg 2015 – wissenschaftliches Programm
UP 7.3: Hauptvortrag
Donnerstag, 26. März 2015, 12:00–12:30, C/gHS
Krypton-85 and Radioxenon: Environmental Tracers and Indicators for Nuclear Activities — •Clemens Schlosser, Verena Heidmann, Martina Konrad, and Sabine Schmid — Bundesamt für Strahlenschutz, Rosastraße 9, 79098 Freiburg
Already in the 1940s scientists recognized the usefulness of radioactive noble gases as for monitoring nuclear activities. Krypton-85 is a very good indicator for the reprocessing of nuclear fuel and Xe-133 can be used for the detection of clandestine nuclear weapon tests and nuclear reactor operation. Additionally, Kr-85 can be used as tracer in environmental sciences. The German Federal Office for Radiation Protection (BfS) operates a noble gas laboratory and a global network which continuously monitors the Kr-85 and Xe-133 activity concentrations in ground level air since the 1970s. The laboratory of the BfS and the techniques used will be presented. Currently, the mean activity concentrations at German sampling sites are approx. 1.5 Bq/m3 for Kr-85 and in the order of 1 mBq/m3 for Xe-133. Based on the long time series of the BfS the global atmospheric distribution and the influence of different sources on the atmospheric activity concentrations over the last decades are discussed. Since 2004, radioactive Xenonisotopes are continuously measured at Schauinsland by an automated system *SPALAX* as part of the International Monitoring System of the Comprehensive Nuclear-Test-Ban Treaty (CTBT). The network capacity of this global monitoring network is demonstrated on the basis of particular events, like the Fukushima nuclear power plant accident and the Nuclear Weapon Tests in North Korea.