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C-8
Table C-5. Energy Support Ratios in Year 2050 for Various Nuclear Policy Options
(Support Ratio = Installed Nuclear Capacity Outside Ener y Center/Installed
Nuclear Capacity Inside Energy Center B
Advanced Support Ratlo
Converter
Ootion 1 E* 1 2 3 4 5u 5T 6 7 8
*System with standard LWR only.
m 1.54
m 1.47
m 0.49
m 0.24
m 2.42
m 2.10
m 1.85
m 1.77
High-Cost U308 Supply
0.72 m 5.69 3.74
0.76 m 6.33 3.86
0.92 m 5.79 3.07
0.24 * 4.02 2.50
Intermediate-Cost U308 Supply
1.65 m 5.06 5.05
1.65 m 4.78 4.78
0.94 m 4.03 3.84
1.82 m 3.30 3.20
As pointed out previously, with only 3 million ST of U308 available below $160/lb,
the only systems that satisfy the energy demand of 350 GWe in the year 2000 and 15 GWe/yr
thereafter are those with breeders. The disadvantage of the classical Pu-U breeder cycle
(Option 3), of course, is the low energy support ratio since the pl'utonium that is produced
must be used in the energy centers. One technique for increasing the energy support ratio
is to load thorium in the blanket of these breeders, while retaining plutonium and uranium
in the cores. The 233U that is produced in the blankets is then burned in denatured LWRs
located outside the centers (Option 6). The resulting energy support ratios for Option 6
vary from 1 to 2, depending upon the advanced converter option. Option 7 introduces a
denatured FBR which would provide 233U to the system and therefore should increase its
nuclear growth potential.
demand itself, the addition of the denatured breeder in Option 7 actually had a minimal
impact.
1.27
2.13
1.07
1.26
5.37
4.78
1.03
However, since Option 6 can meet the projected nuclear growth
The energy support ratios of Options 6 and 7 could be further increased by replacing
the uranium in the core of the Pu-U breeder with thorium (Option 8). With the high-cost
U308 supply, energy support ratios of about 3 are obtained for this system. The intro-
duction of thorium in the core of a breeder lowers the breeding ratio to the point that,
in contrast to Option 7, significant quantities of FBRs operating on denatured fuel must be
built to meet the projected nuclear growth demand.
2.74
1.46
2.13
1.06
1.28
5.37
4.78
1.04
2.74
3.09
3.27
2.89
3.11
5.49
4.78
3.07
3.62
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