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

4.105
4.9.3 Detailed Predisposal Cost Estimates for Geologic Disposal
This section describes in greater detail the predisposal cost estimates for the example
geologic disposal alternative. Costs are derived for both the once-through and reprocessing
cases.
4.9.3.1 Once-Through Fuel Cycle
Table 4.9.3 lists the costs associated with once-through predisposal operations.
Reactor basin storage is estimated to cost about $6/kg HM per year with storage periods on
the order of five years, for an equivalent present-worth cost of about $25/kg HM.
After storage, the fuel assemblies may be: 1) packaged intact, 2) disassembled and
packaged, 3) chopped, voloxidized, and packaged, or 4) chopped, the fuel dissolved, and
converted to glass. Treatment costs shown in Table 4.9.3 for the above options range from
$18 to $92/kg HM due to the increasing complexity of these operations.
Costs for independent unpackaged water basin storage of spent fuel vary significantly
with the size and capacity utilization of the facility. Costs for storage in a non-
expandable 3000 MTHM basin are estimated at about $117/kg HM.(a) Costs for a 5000 MTHM non-
expandable basin (DOE 1978), using unit cost assumptions in this Statement are estimated at
$80/kg HM.(a) Estimates for a facility expandable to 20,000 MTHM are $45/kg HM.(a) In
addition, costs vary nearly inversely with capacity utilization. For example, if a facility
utilized only 50% of its capacity, unit costs would be almost doubled.
Other storage options include storage of packaged spent fuel. In these cases, spent
fuel could be packaged in facilities located adjacent to storage facilities. Table 4.9.3
illustrates costs for four such design concepts. Dry well storage appears to be the most
cost effective alternative.
Packaging of the spent fuel could be done either at facilities adjacent to storage
basins or at the repository. Packaging facilities that are integral with the repository
are assumed for the example system here and may be more cost effective due to lower trans-
portation costs for unpackaged spent fuel.
Transportation costs include transport of the spent fuel from reactor storage to inde-
pendent storage (25% of the fuel), reactor storage to repository (75% of the fuel) and
independent storage to repository (25% of the fuel).
Total predisposal costs for the example case in Table 4.9.3 are about $103/kg HM. The
range is estimated using the lowest and highest cost options.
(a) In the cases shown in Table 4.9.3, it is assumed that only about 25% of total spent
fuel discharges are sent to independent storage and the cost is reduced proportionally.