Swipe check: Collecting and analysing environmental samples

The air is pressurized, carefully filtered and closely monitored. Scientists and technicians pass through air showers before entering. Welcome to the IAEA Environmental Sample Laboratory, or 'clean laboratory', in Seibersdorf, Austria, where more than 300 samples are analysed every year to verify that nuclear facilities have been used as declared. The clean laboratory conditions are necessary so that the smallest traces of uranium and/or plutonium can be identified in the swipe samples taken by inspectors at research reactors, enrichment plants and other nuclear facilities for analysis. The machines used are so sensitive that they can pick out uranium and plutonium at weights below one trillionth of a gram in a sample. While many safeguards verification methods aim to check and confirm the type and quantity of nuclear material declared by a State, environmental sampling is used to verify the absence of undeclared nuclear material.