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and the ~ dvent (or carrier) salt and, therefo~e, would actually require
a larger uranium supply than the 30-year once-through fuel cycle proposed
for the reference IBmR concept. However, uranium is easily and effectively
separated frsm the rest of the fuel mixture, so the denatured uranium
could be removed and recycled %e: the reactor site with a minimum of ef-
fort. Depending on the rate 06 salt replacement, this approach would
significantly reduce the requirement for fissile uranium below that fsr
the simple once-through cycle
4.2 Fuel Cyde Performance
Of the alternate fuel cycles considered in this secti~n, the break-
even breeder, if it were successfd, would provide for the best utiliza-
tion of fissile fuel resources ~ ~ 3 % ) . ~f that system were started up
on 20% e ~ r i ~ 2h 3 e % ~ ~ it ~ would probably require 700 to 1000 ~g of natu-
ral U308 to provide the initial fuel loading for each 1 CX of electric
generating capability. [The separative work to enrich this fuel to 20%
235U would be less than 1 million separative work units (SWU),]
However,
once provided, this fuel would continue to p~~dluce electricity in an arbi-
trarily long succession of power stations (or as long as fertile material
was available). Thus, the effective resource requirement could be made
arbitrarily small by averaging It Over iB large number Of plants. Even if
the initial fuel charge were used in only one pliant, the resource require-
ment would be only 110 to 20% of that for an LWR with similar electric gen-
erating capability.
The converter options with fuel processing provide other estimates of
the potential performance of DMSRs with fissi~n-product cleanup (Table 29).
The options, which were described earlier, my be sumarized as f~klows:
Option Fuel cycle
A
B
c
D
Initial load is 20% 235U; makeup fuel is 20% 235U
Initial load is 20% 235U; makeup fuel is 33% 735U
Initial load is 20% 23sU; annual discard of 1% of uranium inventory;
makeup fuel is 20% 235U
Initial load is 20% 235U; annual reenrichment of 2% of uranium inventory
to denaturin limit or to one-lialf of prior 7 3 8 ~ content;
makeup fuel is 20% 255C