The FuTure oF nuclear Fuel cycle - MIT Energy Initiative

On the other hand, the introduction date of thermal reprocessing in preparation for the
deployment of fast reactors has an appreciable effect in the initial few years after the FR
introduction, as can be seen for the year 2050 in Table 6.11. The effect disappears completely
by 2070, and the dynamics of TRU availability takes over after that time. Thus the
trajectories of the installed FR capacity are close for the two cases examined after 2060.
Table 6.11 Fast Reactor’s Installed Capacity for the cCse of 2.5% Growth [GWe]
thermal reproCeSSinG
StartinG year Fuel CyCle by 2050 by 2100
2030
2035
Fr cr=0.75 28 248
Fr cr=1.0 32 337
Fr cr=1.23 31 387
Fr cr=0.75 20 259
Fr cr=1.0 23 345
Fr cr=1.23 21 391
Sensitivity to initial core fuel requirements
Since the fuel requirements for the fast reactor breeder were extrapolated from the smaller
design of the ALMR, it is important to assess the effect of possible improvements (i.e. savings
in fuel requirements). Two simulation cases were run for an assumed fuel-saving fast
breeder reactor. The new cases with reduced fuel requirements were assumed to require
only half as much as the difference between the ALMR and the CR=1 cases in the side
bar on fast reactors. In the base cases described in the sidebar, a breeder reactor takes 8.64
MT TRU to start as opposed to 6.31MT TRU for the CR=1 case. The total heavy metal in
the startup core is 97.31 MTHM instead of 45.5 MTHM in the CR=1 case. The reduced
fuel requirements assumed for the sensitivity study are: the breeder needs only 7.47 MT of
TRU in the initial core and only 72 MTHM in the core and blanket. With these assumed
requirements, two cases were run, one keeping the breeding ratio at 1.23, and one assuming
a smaller breeding ratio of only 1.115. Table 6.12 shows the resulting installed fast reactor
capacities in 2050 and 2100 for the base growth case of 2.5% per year.
Table 6.12 Effect of TRU Requirements
on Fast Reactor Installed Capacity For
the growth case of 2.5% per year [GWe]
ConverSion ratio by 2050 by 2100
Fr cr=1 23 345
Fr cr=1.23 21 391
Fr cr=1.23* 25 477
Fr cr=1.115* 25 408
*Breeder cases with reduced fuel requirements
It is clear from the table that by 2050 there would be little change in the installed capacity.
However, by 2100 the installed capacity will increase if the core with reduced requirements
was able to keep the same conversion ratio of 1.23, from 391 to 477 GWe, an increase of
22%. On the other hand, if the reduced fuel requirements led to a decrease in the conver-
chapter 6: analysis of Fuel cycle options 91