Maintaining the uranium resources data system and assessing the 1989 US uranium potential resources

Abstract

Under the Memorandum of Understanding (MOU) between the EIA, US Department of Energy, and the US Geological Survey (USGS), US Department of the Interior, the USGS develops estimates of uranium endowment for selected geological environments in the United States. New estimates of endowment are used to update the Uranium Resources Assessment Data (URAD) System which, beginning in 1990, is maintained for EIA by the USGS. For 1989, estimates of US undiscovered resources were generated using revised economic index values (current to December 1989) in the URAD system's cost model. The increase in the estimates for the Estimated Additional Resources (EAR) and Speculative Resources (SR) classes resulted primarily from increases in the estimates of uranium endowment for the solution-collapse, breccia-pipe uranium deposit environment in the Colorado Plateau resource region. The mean values for $30-, $50-, and $100-per-pound U{sub 3}O{sub 8} forward-cost categories of EAR increased by about 8, 48, and 32 percent, respectively, as compared to 1988. Estimates of the 1989 undiscovered resources in the SR class also increased in all three forward-cost categories by 10, 5, and 9 percent, respectively. The original cost equations in the URAD System were designed to cover drilling costs related to extensive flat-lying tabular oremore » bodies. The equations do not adequately treat drilling costs for the smaller areas of vertical breccia pipe uranium deposits in the Colorado Plateau resource region. The development of appropriate cost equations for describing the economics of mining this type of deposit represents a major new task. 12 refs., 4 figs., 5 tabs.« less