Year
2011
Abstract
Surface smears using cotton swipes at nuclear facilities are one of the standard sampling protocols used by International Atomic Energy Agency (IAEA) inspectors to verify treaty compliance. These swipes are then chemically treated to isolate nuclear materials for subsequent instrumental analysis. Uranium isotopic composition is a key parameter in assessing adherence to nuclear safeguards and non-proliferation agreements. As such, the characteristics of the cellulose collection media must not significantly impact the accuracy of the uranium analysis. Standard cotton swipes typically contain 1-4 ng of natural uranium. If a given sample does not contain significantly more uranium than the swipe itself, the isotopic signature from the nuclear facility is diluted and/or perturbed A study is underway to survey other potential sampling media that may be more effective in collecting nuclear materials and at the same time contain less uranium. Approximately 40 natural and synthetic fiber swipes are being tested. A few are coated with complexants and/or solvents during the manufacturing process. Adhesives and tapes are also included. The relative merits of each sampling matrix is being reviewed on the basis of: 1) efficiency in collecting uranium from surfaces, 2) the ease by which the swipe fabric is separated from the nuclear components, 3) latent uranium background of the swipe, 4) the impact that any dissolved swipe components might have on the chromatographic recovery of uranium, and finally, 5) the presence of any isobaric interferences that the dissolved swipe might contribute to the background during MS analysis. Results from this survey will be compared to the standard cotton swipe and recommendations will be presented for the most promising candidates for further consideration. This presentation will discuss results acquired to date in this stud