The FuTure oF nuclear Fuel cycle - MIT Energy Initiative

table 7a.2 once-through Fuel Cycle Specifications
Burn-up 50 MWd/kghM
cycle length 1.5 years
core mass, uoX 84.7 MThM/GWe
Fuel batches 3
Fuel batch residence time 4.5 years
Thermal efficiency 33%
Generation per kghM uoX 10.04 kWe
loss during conversion 0.2%
loss during enrichment 0.2%
loss during fabrication 0.2%
lead time for ore purchase 2 years
lead time for conversion 1.5 years
lead time for fabrication 0.5 years
enrichment of uoX 4.5%
optimum Tails assay 0.29%
Feed 10.05 (initial kgu/enriched kgu)
Separative Work units 6.37
reactor life 40 years
Incremental capital costs 40 $ million/GWe/year
decommissioning cost 700 $ million/GWe
Fixed o&M costs 56.44 $/kW/year
Variable o&M costs 0.42 mills/kWh
depreciation, MacrS schedule 15 years
Tax rate 37%
Spent fuel pool storage period 5 years
In most other studies that calculate the LCOE for
the Once-Through Cycle, the time frame most commonly
used, [A,B], is the useful life of a single reactor—e.g.
40 years—with allowances at the front-end
for the construction period and at the back-end for
dismantling. Separate calculations will have been
made to take costs incurred outside of this time
frame—such as the cost of preparing a disposal site
or the costs of constructing a reprocessing facility—
which translate these expenditures into a levelized
charge paid within the time frame [A,B]. So long as
all costs are accounted for and present valued in a
consistent fashion, it is immaterial what reference
time frame is employed. In our calculations, [A j ,B j ]
is the time that a unit of fuel is resident in a reactor—e.g.
4.5 years—together with buffer periods at
the loading and unloading when the relevant fabrication
and interim storage operations occur. This
time frame is much shorter than the life of the reactor,
so we treat reactor costs in the same way that
the usual calculation treats disposal costs: in a side
calculation we determine a rental charge for the reactor
that must be paid while the fuel is resident, i.e.
for t∈[A j ,B j ]. This charge is set so that the combined
rental fees paid by all of the units of fuel resident
over the life of the reactor equal the cost of the reactor
in present value terms.
Once-Through Cycle
Table 7A.2 shows the key engineering and other economic assumptions used to calculate
the LCOE for the Once-Through Cycle.
To illustrate how we calculate the levelized cost components, we calculate the levelized cost
of the raw uranium, u 1 , as follows. Based on our assumptions, in order to have 1 kgHM of
UOX fuel we require 10.05 kgHM of fresh uranium ore (yellowcake) at the assumed price
of $80/kgHM, which is converted into 10.03 kgHM of uranium hexafluoride. We assume a
2-year lead time for ore purchase. Given our assumptions, each kgHM of UOX fuel has the
effective electricity generating capacity of 10.04 kWe throughout the 4.5 years it is resident
in the core. With 8,766 hours in a year, this enables us to calculate the levelized cost of raw
uranium per unit of electricity produced as:
where r is the annual discount rate and R is the continuously compounded discount rate.
Similar calculations for the other components give the values reported in Table 7.2 in the
main chapter.
176 MIT STudy on The FuTure oF nuclear Fuel cycle