Environmental Engineering Reference
In-Depth Information
Impact limiter
Neutron shielding shell
Neutron shielding
Closure lid
Outer steel shell
Lead gamma shielding
Inner steel shell
Basket
Figure 8.7
Generic rail cask (Courtesy of the Nuclear Regulatory Commission)
cask is to be used over a long period of time, normal wear and tear on the cask,
operational procedures, and maintenance requirements need to be considered in
the design phase. The cask must be designed to meet NRC and DOT perfor-
mance requirements under normal and accident conditions. All of these factors
are taken into account in selection of the composition and thickness of the cask
body, lid, and impact limiters.
Another consideration in the design of the cask is the interface with existing
facilities where used fuel is currently stored and the facilities to which it will
be taken. The lifting trunnions, lid and fasteners, supports and tie-downs must
be compatible with the handling equipment at the places where the used nuclear
fuel is going to be loaded and unloaded. Since there are many different types
of nuclear power plants operating in the United States and many different sizes
of nuclear fuel assemblies being used, some effort will be required to design a
transportation system that can be compatible with all of them. In addition, the
shipping casks will have to be compatible with the handling equipment at the
repository, interim storage facility, or reprocessing facility.
As mentioned earlier, over 3,000 shipments of used nuclear fuel and high-level
waste have been made in the United States. Obviously, the casks to transport
this material exist. Several different types of casks have been built and currently
have certificates of compliance. A few of these casks and their characteristics are
shown in Table 8.3. Although the current casks meet the federal requirements and
serve for transporting a few used fuel assemblies, a fleet of casks with a standard
design will be needed to move the used fuel once the federal government decides
whether to store, bury, or reprocess/recycle it.
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