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

Draft pp 1.10, 1.23, 3.1.133
Issue
190
COSTS
The discussion of costs and capacities for repositories in different media for the two
fuel cycles is confusing and some of the data appears contradictory. For example:
1. The unit power costs do not appear to reflect the construction costs.
2. Why does a basalt repository cost $500 million more than one in granite if the dif-
ficulties of mining in granite are comparable?
3 Why do the construction costs between fuel cycles for the same media vary in a seem-
Response
ingly unrelated pattern? ('208-NRC)
DOE agrees that some of the cost relationships are confusing since the data necessary
to obtain an understanding of the costs appear in different locations. The repository cost
tables in the final Statement have been revised into a single table in Section 5.6 which
consolidates all of the necessary information. This table is reproduced below for
reference in answering the specific questions above. Unit power costs are shown in the
last column of the table for additional reference. All repositories have the same total
area (800 ha or 2000 acres).
1. The ratios of unit power costs between media differ from ratios of construction cost
for the reasons below:
* Unit power costs include the effect of repository waste capacity.
* Unit power costs include predisposal costs.
* Unit power costs include the effect of the cost of money on costs through
discounting.
The effect of the latter two reasons on cost can be discerned by comparison of the
unit heavy metal costs in column 7 with the unit power costs in column 8. The largest
effect by far, however, is the difference in waste capacities (noted in column 4 in the
table) in the repositories due to the different thermal loading limits in various
media. Thus, while the construction cost for a basalt repository is three times that
of a salt repository, the unit heavy metal cost is only 67 percent greater since 2.4
times more waste can be stored in basalt than in salt.
2. The unit costs of mining basalt were estimated to be about five percent greater than
those for mining granite. Most of the cost difference, however, is due to differences
in mining requirements as noted in column 3 in the table.