PRODUCTION, IMPORT/EXPORT, USE, AND DISPOSAL

PRODUCTION
Uranium is present in the earth's crust at approximately 3 ppm (2 pCi/g) (du Preez 1989). Although there
are more than 100 uranium ores, carnotite, pitchblende, coffinite, uraninite, tobernite, autunite,
tyuyamunite, and a few others are the main ores of commercial interest. The main ores are described in
Table 4-1. The most economically attractive uranium ores have uranium concentrations in excess of
1,000 ppm (700 pCi/g) (Stokinger 1981; Weigel 1983). In the United States, the major ore deposits are
located in Colorado, Utah, Arizona, New Mexico, Wyoming, Nebraska, and Texas (EPA 1985a). The steps
necessary to produce uranium for its various uses include mining, milling, conversion to uranium
hexafluoride (UF6), enrichment, reduction to metal or oxidation to uranium oxide, and fabrication into the
desired shape. The steps for preparing commercial reactor grade, submarine reactor grade, or weaponsgrade
uranium are the same, except the last two require a more aggressive enrichment process. Depleted
uranium metal is produced by reducing the depleted uranium hexafluoride byproduct. Conventional
fabrication methods are used to configure the uranium for specific uses, such as rectangular solid blocks for
helicopter rotor counterbalances and parabolic or cylindrical solids for military depleted uraniu...

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