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

5.6 COST OF GEOLOGIC DISPOSAL
5.94
Constant dollar(a) costs have been estimated for isolating both spent fuel and fuel
reprocessing wastes in salt, granite, shale, and basalt formations. The costs include all
construction, operating, and decommissioning costs. The costs of federal programs for
repository research and development have not been included in the costs stated here, but are
included in the systems cost estimates in Chapter 7. The cost estimates are stated in terms
of constant 1978 dollars.
Results of this analysis show that for spent fuel repositories of constant size
(800 ha), construction costs including mining and backfilling range from $1 billion for
bedded salt media to $3 billion for basalt media. Total operating costs vary from $590 mil-
lion for a repository in salt to $2.4 billion for one in basalt. However, since the allow-
able waste emplacement density in basalt is about 2.5 times greater than that in salt, unit
costs for disposal in basalt are only about 70% higher than for disposal in salt. Costs of
disposal in shale are similar to those in salt and costs of disposal in granite are similar
to those in basalt. Cost estimates for reprocessing-waste repositories follow a similar
pattern.
5.6.1 Construction Costs
The repository construction cost estimates include owner's costs as well as facility
construction. Owner's costs include land acquisition, startup costs, owner's staff costs
and other costs incurred by the owner--in this case the Federal government or its
contractor--during construction. Facility construction costs are defined here to include
the costs of all labor, equipment (including waste transport and emplacement equipment),
buildings and structures, site improvements, shaft, corridor and room mining, backfilling,
and architect/engineer services. Interest during construction is taken into account by dis-
counting prestartup construction costs at 7% per year (constant dollar rate which excludes
inflation). Construction cost estimates were generally based on designs prepared by the
Office of Waste Isolation (OWI) in documents Y-OWI/TM-36, Vol. 1-23. These designs have
been revised somewhat to reflect more efficient shaft design, construction and usage,
revised mining schedules, increased surface storage of mined rock, and more workable surface
handling facilities (see Vol. 4, Chapter 7 of DOE/ET-0028 (DOE 1979) or Section 5.3 of this
Statement for repository descriptions). Construction costs are derived by estimating
requirements for major equipment, buildings and structures, site improvements, and construc-
tion labor. These direct cost estimates are then factored to generate other direct costs,
architect/engineer costs, and owner's costs.
The construction cost estimates, including a contingency factor, have an estimated
accuracy range of +20%. This accuracy range reflects the uncertainties that are likely to
be encountered during design and construction, but which are difficult or impossible to
(a) The term constant dollars means that the dollar value of the estimates in all future
time periods is the same as the value of the dollar in the reference year (1978 in this
statement); i.e., the effects of inflation are removed.