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

4.1
CHAPTER 4
PREDISPOSAL SYSTEMS
After radioactive wastes are generated and before their disposal, several predisposal
operations are required. The combination of these operations is referred to in this State-
ment as the predisposal system. The system operations include treatment and packaging to
prepare the waste for the specific requirements of a disposal option, interim storage if the
treated waste cannot be shipped immediately to a disposal site, and shipment to interim sto-
rage and/or to a disposal site. Decommissioning of the waste management facilities,
although not a predisposal operation, is discussed in this chapter because it produces
wastes which must be managed in a manner similar to those wastes produced by fuel reproces-
sing and MOX fuel fabrication plants.
This chapter provides examples of processes and facilities that could be used to carry
out these predisposal operations for both the once-through cycle and the reprocessing cycle.
The processes and facilities described here are not dependent to a significant degree on the
size of the nuclear system served. For each required step, one or more concepts have been
examined in detail to characterize the environmental impacts of construction, operation and
decommissioning, the impacts of potential accidents, the dollar cost of construction and
operation, and the safeguard requirements. Summary results of these evaluations are pre-
sented here. Detailed results are available in DOE/ET-0028 and DOE/ET-0029.
All of the concepts evaluated here are considered to represent available technology;
that is, enough information is available to initiate design and construction of full-scale
facilities, although varying degrees of design verification testing may be required. Brief
descriptions are also provided of a number of alternative high-level waste treatment con-
cepts that do not represent available technology but have attractive attributes that make
them potential alternatives.
4.1 RELATIONSHIP OF PREDISPOSAL OPERATIONS TO DISPOSAL AND PROGRAM ALTERNATIVES
The relationships of the predisposal operations to the unique system requirements for
each disposal alternative, for both the once-through and the fuel reprocessing cycles, are
described in this section. The individual components of the predisposal systems are then
described and analyzed in subsequent sections.
4.1.1 Predisposal System for the Once-Through Cycle
A simplified diagram of the predisposal waste management system for spent fuel in the
once-through fuel cycle is shown in Figure 4.1.1. For the example predisposal system
assumed here, the spent fuel is stored at the reactor storage basins for a minimum of
5 years. The fuel may be stored there for a longer period if a disposal facility is not
available and if capacity is available at the reactor. The fuel is then shipped to a