ORNL-5388 - the Molten Salt Energy Technologies Web Site

7-35
cycled in Pu/Th converters, the systems have potential nuclear growth rates that exceed
those of analogous reactors operating on the Pu/U fuel cycle. If the intermediate-cost
U308 supply assumption proves to be correct, advanced converters in the recycle mode can
*
satisfy the postulated nuclear energy demand through year 2050 at competitive costs.
This analysis therefore indicates that, at least under optimistic resource conditions,
advanced converters using denatured fuels can defer the need for commercial use of an
"inexhaustible" energy source (such as FBRs) beyond the year 2050.
FBR Systems, Options 3, 6, 7, and 8
Table 7.4-2 shows that almost all of .the nuclear system options using FBR fuel
cycles (Options 3, 6, 7, and 8) are able to meet the projected nuclear energy demand
without mining U308 costing more than $160/lb.
case of the high-cost ore supply, and even this option, which includes the Pu-Th/Th
breeder and the denatured 233U breeder, would satisfy the demand if slightly improved FBR
reactor design parameters were used, Thus, as was expected, this analysis indicates that
FBR-containing systems will potentially support much larger nuclear capacities than
thermal recycle systems and/or will require less mining. The Th-containing FBR cycles
supporting dispersed denatured converters perform as well as the analogous Pu/U cycles
within the framework of this analysis.
core and Th blanket is particularly resource-efficient.
The only exception is Option 8 for the
Of the Th-containing cycles, the FBR with a Pu/U
7.4.4. Results for Unconstrained Resource Availability
The preceding results represent a somewhat artificial situation because of the
$160/lb limitation on the U308 availability.
power demand in many of the scenarios investigated is a direct result of the system's
inability to utilize U308 costing more than $160/lb. In order to address the potential
of the various fuel cycle/reactor options under the condition that the projected demand
for nuclear power must be satisfied, the $160/lb constraint was removed. The cumulative
quantity of U308 required to completely satisfy the demand for nuclear generating capacity
was then estimated for each of the nuclear power options; these results are presented in
Table 7.4-3.
That is, the failure to meet the projected
The rate at which U308 is required to support the projected nuclear capacity
represents an important additional constraint on a system.
An overall maximum U308
production rate is difficult to specify because of the possibility of importing U308
and because any prediction of the production of U308 from uncertain resources in the next
century is highly speculative.
Recognizing this, and also recognizing that the required
U308 production rate is still an important variable, the maximum required U308 production
rates for each scenario were estimated and are tabulated in Table 7.4-4. As a point of
reference, note that DOE has estimated that domestic mining and milling could sustain a
production rate of 60,000 ST of U308 per year in the 1990s by developing U308 reserves
and potential resources at forward costs of less than $30 per pound.
*
Forward costs do not include the capital costs of facilities or industry profits, which
are included in the long run marginal costs used in this study.