The Location, Identification, and Size Distribution of Depleted Uranium Grains in Reservoir Sediments was the title of a paper presented by Doris Lo '07 at the recent American Geophysical Union meeting in Baltimore. Co-authors were Geology Research Professor Robert Fleischer and former student Elizabeth Albert and Professor John Arnason of the Department of Earth and Atmospheric Sciences of the University at Albany.
Environmentally undesirable, uranium-rich grains in sediment layers can be identified by analysis of etched particle tracks from nuclear fission produced by neutrons. Each uranium-rich particle produces a sunburst of tracks in which the number of tracks reveals the size of the particle.
From 1958 to 1984, National Lead Industries processed depleted uranium at its plant in Colonie, N.Y. Depleted uranium particles emitted from its exhaust stacks have been found up to 40 kilometers away. The group studied a sediment core taken from a small body of water, the Patroon Reservoir near the now abandoned National Lead plant. Use of that core demonstrates how induced nuclear tracks can locate microscopic high-uranium grains for further mineralogical study; determine the size distribution of uranium grains; and help analyze the average isotopic depletion of the uranium when total uranium concetrations are known.
The authors conclude that the size of depleted uranium particles found in the sediment was controlled by both atmospheric transport from stack to reservoir and water transport within the reservoir.