ORNL-5388 - the Molten Salt Energy Technologies Web Site

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between 1991 and 2001 were assumed to have U&, requirements equal to 80% of the standard
LWR, with the improvements retrofitted to all existing reactors at that time. Finally,
those plants beginning operation after 2001 were assumed to have U308 requirements equal
to 70% o f the standard LWR, again with the improvements retrofitted to existing plants.
In addition, the effect of a lower enrichment tails assay was examined for both the
standard and the optimized LWR designs.
The standard enrichment tails schedule assumed
that the assay fraction was a constant 0.0020. The reduced tails schedule began at 0.0020
but decreased to 0.0005 between 1980 and 2010 and remained constant thereafter.
The latter
tails schedule was assumed to represent a changeover to an improved enrichment technology.
The effects of considering both the improved LWR design and the improved tails
technology are sumnarized in Table 7.4-5. The results show that with tails improvements
alone the U308 requirements may be reduced by 16% by year 2029. This reduced level of
U308 consumption translates to an increase in the maximum installed capacity of approxi-
mately 60 GWe for standard LWRs on the throwaway/stowaway fuel cycle.
Table 7.4-5. Comparison of U308 Utilization of Standard and Improved
LWRs Operating on Throwaway/Stowaway Option With and Without
Improved Tai 1 s
ST U308/GWe
Standard LWR Technology Improved LWR Technolow
Normal Improved Normal Improved
Year Tai 1 s Tai 1 s Tails Tai 1 s
1989 5236 4759 4649 4224
2009 6236 4508 4079 3560
2029 5236 4398 3923 3346
*Normal tails assume 0.2 w/o 235U in 238U; improved tails as-
sumed 0.05 w/o 235U in 238U; 75% capacity factor.
With improved LWR technologies (no tails improvements) the U308 consumption levels
could be reduced *25% in year 2029.
maximum installed capacity for optimized LWRs.
technologies were used, the maximum achievable installed nuclear capacity would increase
by about 144 GWe.
This translates to an increase of 100 GWe in the
If both reduced tails and advanced LWR
It is important to place these results within the perspective of the results re-
ported in Table 7.4-2.
improvements are comparable to those for standard LWRs operating on the classical Pu/~~*U
recycle mode or on the denatured 23% cycle.
The maximum installed nuclear capacities obtained with these
Obviously, if both improved LWRs and Pu
recycle were available, the nuclear capacity could be even greater.