The last two columns of Table 12.9 give the unit cost of product, in dollars per kilogram of uranium and dollars per gram of 235U, calculated from Eq. (12.152), with zp = 0.00711, the assumed transaction tails assay of хц/ = 0.003, and the unit costs employed in Sec. 5 of Chap. 3, cp = $89.11/kg uranium and eg = S100/SWU, which lead to the equation:

(2yP — 1) In + 219.5666yp — 6.4300

(12.157)

Because costs change frequently, this equation must be considered an example rather than a permanent relation.

Figure 12.19 has been calculated from Eq. (12.157). It shows the dependence of the unit cost of enriched uranium, in dollars per gram of 235 U, on the weight percent 235 U and shows the contributions to this cost from natural uranium feed and enrichment.