Management of Commercially Generated Radioactive Waste - U.S. ...

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Unit costs for the present inventory and present capacity cases are substantially
higher than for the higher nuclear growth cases because of the small amount of
electricity generated relative to the fixed costs.
Assuming a 7% discount rate and continued growth of the nuclear industry, total
high-level and TRU waste management costs lie in the range of 0.6 to 1.0 mill/kWh.
4. Interim storage requirements for spent fuel are substantially greater for the
alternative program than for the proposed program with the once-through cycle.
With the reprocessing cycle, spent fuel storage requirements are controlled by
reprocessing capacity and are not sensitive to the waste management program alter-
natives. Storage requirements for reprocessing waste, however, become substantial
with the alternative program.
Spent fuel storage requirements are maximized with the no-action alternative.
5. Transportation requirements are higher for the alternative program compared to the
proposed program with both the once-through and the reprocessing fuel cycles.
Transportation requirements are minimized with the no-action alternative.
6. Age of the waste. A potentially beneficial aspect of the alternative program is
the aging of the waste, which results in reduced radioactivity and heat generation
rates which can be used to reduce repository space requirements or to further
reduce the temperatures in the repository.
7. Geologic repository requirements are sensitive to the geologic medium selected,
the nuclear growth rate, and the fuel cycle employed. For the highest growth
assumption considered here, these requirements for operations through the
year 2040 range from two to seven 800-hectare repositories for the once-through
cycle and from four to nine 800-hectare repositories for the reprocessing cycle.
8. The radioactivity inventory in disposal repositories is proportional to the nuclear
energy generated. The ultimate accumulation is not sensitive to the time
when disposal commences but is affected by the amount of plutonium recycled and
thus to the time when recycle is started.
The inventory of fission and activation products is closely similar for both the
once-through and reprocessing cycles. However, the actinide radioactivity inven-
tory is larger for the once-through cycle than for the reprocessing cycle because
all of the plutonium remains with the spent fuel. The difference in actinide
activity between the two cycles is not, however, proportional to the amount of
plutonium in the waste. This is because recycle of plutonium produces more of the
higher actinides (e.g., americium and curium isotopes), which are discarded in the
wastes. Thus, rather than a factor of 100, which could be expected on the basis
of the amount of plutonium discarded, the actinide activity in the spent fuel
waste is on the order of only 2 to 10 times larger than the reprocessing cycle
wastes.