Verication of an FMCT The Case of Enrichment Facilities

One challenge to a potential verication regime for a Fissile Material Cuto Treaty would be to conrm that a sample of nuclear-weapon-usable material was produced prior to entry-into-force of the treaty, especially if facilities that were part of a nuclear weapons complex are converted to civilian use rather than shut down. Namely in older enrichment plants, environmental sampling techniques might detect particles from past production of highly enriched uranium (HEU). While methods are available to determine the age of nuclear materials based on the concentrations of decay products, micron-sized uranium particles are particularly dicult to analyze.We will review the sensitivity requirements for age determination of HEU particles in an FMCT, and assess the potential of advanced measurement techniques available for this application.