When plutonium is separated from spent nuclear fuel, the fission gas isotope krypton-85 (Kr-85) is released to the atmosphere in the course of the chemical process. Because this noble gas isotope has no relevant natural sources, it can be used as an indicator for clandestine production of plutonium, which is a nuclear-weapons-usable material.

Global Kr-85 emission data are collected at the University of Hamburg and made available through this database. The world map below shows the location of 28 nuclear complexes with Kr-85 emissions. The sources of the data are detailed in an Occasional Paper by Ahlswede et al.

For more details of the source emissions and the measurements please follow the links on the sitemap.

Please notice that some descriptions about reprocessing plants are still in progress. There are occasional updates.