An estimate of uranium resources in the United States more detailed and more recent than that of Table 5.17 provided by the U. S. Department of Energy in May 1978 [Ul] is summarized in Table 5.18. “Reserves” corresponds approximately with the “Reasonably assured resources” category of Table 5.17, and “Probable potential resources” corresponds with “Estimated additional resources.” The subtotal at <$30 of 1312 thousand MT in Table 5.18 may be considered an update of the 1361 for the United States in Table 5.17, and the subtotal at <$50 of 1758 thousand MT in Table 5.18, an update of the 1696 in Table 5.17.

“Possible potential resources” are defined [U2] as “those estimated to occur in undis­covered or partly defined deposits in formations.. . productive elsewhere in the same geologic province.” “Speculative potential resources” are defined [U2] as “those estimated to occur in undiscovered or partly defined deposits: 1. in formations … not previously productive within a productive geologic province, or 2. within a geologic province not previously productive.”

To relate these resource estimates to nuclear electric generation, it may be noted that a 1000-MWe pressurized-water reactor operating at 80 percent capacity factor without recycle, on uranium enriched to 3.3 w/o (weight percent) 235 U in an enrichment plant stripping natural uranium to 0.3 w/o 235 U, consumes around 200 MT of uranium per year. Thus the U. S. resource estimate of 1758 thousand MT available at less than $50/lb U308 would keep a 300,000-MWe nuclear power industry in fuel for

Inclusion of uranium in the “Possible” and “Speculative” resource categories would increase the total to 3357 thousand MT and extend the life of a 300,000-MWe nuclear power industry to 56 years.