Year
1999
Abstract
The United States recently purchased highly enriched uranium from the Republic of Georgia. A team of US specialists traveled to Georgia to analyze and package the fresh reactor fuel elements containing uranium. After packaging, the reactor fuel was moved to a different country for storage and eventual disposition. International shipping regulations and criticality safety concerns mandate extensive knowledge of the fuel elements' contents, including the average isotopic composition and mass of uranium present in each shipping container. Bundles of fuel elements were arranged in planar arrays and analyzed by gamma ray spectroscopy to determine isotopic composition and estimate the grams of uranium in each array. A single high-resolution detector was used with two multichannel analyzers to simultaneously collect spectra optimized for the two measurement types. Results from the isotopic analysis showed good precision and close agreement with the declare isotopic composition. Results from the quantitive uranium measurements showed good agreement with declared uranium masses, but precision was not as good as with the isotopic measurements.