ORNL-5388 - the Molten Salt Energy Technologies Web Site

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6.1 .. BASIC ASSUMPTIONS AND ANALYSIS TECHNIQUE
6.1.1. The U308 Supply
The most recent estimates of the supply of U308 available in the United States as re-
ported by DOE'S Division of Uranium Resources and Enrichment (URE) are summarized in Table
6.1-1 (from ref. 1). On the basis of a maximum forward cost of $50/lb, the known reserves
plus probable potential resources total 2,325 x 103 ST. URE estimates that an additional
140 x lo3 ST is available from byproducts (phosphates and copper), so that the amount of
U308 probably available totals 2.465 x lo3 ST (or approximately 2.5 million). If the
"possible" and "speculative" resources are also considered, the URE estimates are increased
to approximately 4.5 million ST. Neither of these estimates include U308 which may be
available from other U.S. sources, such as the Tennessee shales, or from other nations.*
The actual U3O8 supply curves used in the analysis were based on the long-run marginal
costs of extracting U308 rather than the forward costs. The long-run marginal costs con-
tain the capital costs of facilities currently in operation plus a normal profit for the
industry; thus they are probably more appropriate for use in a nuclear strategy analysis.
The actual long-run marginal costs used in this analysis are shown in Table 6-7 of Appendix
B and are plotted in Fig. 7.4-1 in Chapter 7. These sources show that if the recoverability
of the U3O8 supply is such that large quantities can be extracted only at high costs, then
the supply available at a cost of less than $160/lb is probably no more than 3 million ST.
If, however, the recoverability is such that the extraction costs fall in what is considered
to be an intermediate-cost range, then as much as 6 million ST U3O8 could be available at
a cost of less than $160/lb.
In the remainder of this study, these two assumptions are
referred to as "high-cost" and "intermediate-cost" U3O8 supply assumptions.
The rate at which the U3O8 resource is extracted is at least as important as the size
of the resource base. URE has estimated that it would be difficult for the U.S. to mine
and mill more than 60,000 ST of U3O8 per year in the 1990's (ref. 3). (Note: This estimate
was based on developing reserves and potential resources at forward costs of less than
$30/lb.
These costs do not include capital costs of facilities or industry profits.)
Although the combined maximum capability of a coalition of states may exceed this, it is
not possible to specify a definite upper limit until more is known about the locations of
the sources of U3O8 and the difficulties encountered in recovering it. Recognizing this,
and also recognizing that the annual capacity is still an important variable, the nuclear
policy options analyzed in this study were considered to be more feasible if their annual
mining and milling rate was less than 60,000 ST
t
of U3O8 per year.
*Editor's Note: In 1977 the U.S. produced 15,000 ST of U3O8 concentrate (ref. 2).
'Editor's Note: In 1977 the U.S. gaseous diffusion plants produced 15.1 million kg SWU per
year (ref. 4). After completion of the cascade improvement program (CIP) and cascade updating
program (CUP) in the 1980'~~ the U.S. capacity will be 27.4 million kg SWU per year
(refs. 5 and 6). A gas centrifuge add-on of 8.8 million SWU has been proposed for the
government-owned enrichment facility at Portsmouth, Ohio. Considerable enrichment capacity
a1 so exists abroad; therefore, enrichment capacity is inherently a less rigid constraint
than uranium requirements or production capabilities.