Detecting Undeclared Plutonium Production: Standoff Monitoring of Nuclear Reprocessing Plants

This work examines whether and how nuclear reprocessing plants can be remotely monitored for their plutonium production via their krypton-85 emissions. Atmospheric transport modeling is applied to analyze the dispersion of emissions from nuclear reprocessing plants to find the best locations for monitoring stations. Krypton-85 is released during the opening of nuclear fuel rods and is technically challenging to contain. The ability to detect plutonium separation activities is of high interest for the verification of the NPT and a future Fissile Material Cut-Off Treaty. For this study, three nuclear reprocessing plants have been selected for an assessment of the concept. For each case, the emissions from the plant are simulated over one year to create a comprehensive database of atmospheric Kr-85 concentrations as a function of time of year and distance from the plant. A frequency analysis is applied to this data to identify the most suitable locations that fulfill given detection criteria.