Conclusions on plutonium separation from atmospheric krypton-85 measured at various distances from the Karlsruhe reprocessing plant

• Published in: Journal of environmental radioactivity Vol. 73; no. 2; pp. 203 - 222
• Main Authors: Kalinowski, Martin B., Sartorius, Hartmut, Uhl, Stefan, Weiss, Wolfgang
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 2004; Elsevier
• Subjects: Air Pollutants, Radioactive - analysis; Analysis methods; Applied sciences; Atmospheric pollution; Environmental Monitoring - methods; Exact sciences and technology; Geography; Germany; Krypton Radioisotopes - analysis; Krypton-85; Nuclear Reactors; Nuclear safeguards; Plutonium; Plutonium - analysis; Pollution; Spent nuclear fuel reprocessing; Time Factors; Weather; Wide-area environmental monitoring; Germany; Germany, Karlsruhe; Wide-area environmental monitoring; Krypton-85; Plutonium; Nuclear safeguards; Spent nuclear fuel reprocessing; WAK; Atmospheric condition; Radioactive pollution; Radioisotope; Indicator; Krypton 85; Nuclear safety; Fission reactor fuel reprocessing; Sensitivity; Surveillance; Detection limit; Air pollution
• ISSN: 0265-931X; 1879-1700
• DOI: 10.1016/j.jenvrad.2003.09.002

For wide-area atmospheric monitoring, krypton-85 is the best indicator for clandestine plutonium separations. The detection and false alarm rates were determined from weekly samples at five different distances from the Karlsruhe reprocessing plant between 1985 and 1988. The detection rate for the separation of 4 kg of plutonium per week was found to be as high as 80–90% at a distance of less than 1 km, 70% at 5 km, 40% at 39 km, and 15% at 130 km. At distances up to 40 km, the false alarm rate is less than 3.5%. On average, the fuel released 28 TBq krypton-85 per kg plutonium. For weapons-grade plutonium, the krypton signal would be lower by a factor of 2. Hence, the given percentages correspond to the detection probabilities for the separation of a significant quantity (8 kg) of plutonium per weekly sample under the specific meteorological conditions of the WAK. The minimum separation rates that could have been detected are 2 gram of weapons-grade plutonium per week at a distance of less than 1 km, 40 g/week at 5 km, 200 g/week at 39 km, and 1000 g/week at 130 km.