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

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steel canisters (0.76 m dia x 3 m) for shipment to interim storage or to a repository. The
void spaces in the canister are filled with dry sand to reduce the possibility of ignition
of Zircaloy fines in the fuel residue. Alternatives within the packaging without compaction
concept involve separate packaging of the hulls and hardware, deactivation of fines before
packaging, and use of filler materials other than sand (e.g., concrete). Other containers
(e.g., 55-gallon drums) could also be employed.
Figure 4.3.6, the flow diagram for fuel residue packaging without compaction, shows the
steps involved in the process. The quantity of packaged waste resulting from this option is
estimated to be 9.1 canisters/GWe-yr.
Mechanical Compaction of Hulls. Mechanical compaction of hulls is a treatment concept
for fuel residues in which the hulls are separated from the fuel assembly hardware and Zir-
caloy fines, compacted to 50% of theoretical density, and packaged in stainless steel can-
isters (0.76 m dia x 3 m) for shipment to interim storage or to a repository. The Zircaloy
fines are deactivated by oxidation and packaged in identical canisters along with the fuel
assembly hardware. Compaction of the hulls could be done by a variety of processes, none of
which has been evaluated with irradiated hulls. Hydraulic press compaction was selected as
the alternative most technically feasible at present.
The steps of the compaction packaging concept are shown in Figure 4.3.7. Implementa-
tion of this option is estimated to result in 1.6 canisters/GWe-yr of fuel hardware and
3.8 canisters/GWe-yr of compacted hulls.
Hulls Melting Process
The hulls melting concept considered here uses the Inductoslag melting process devel-
oped by the U.S. Bureau of Mines Metallurgical Research Center in Albany, Oregon. In this
SHEAR i FUEL
DISSOLVED L RETRIEVE
FUEL HULLS AND
RECYCLE IHARDWARE
MATRIX
MATERIAL MONITOR
FOR U-Pu
PACKAGE
INTERIM
STORAGE
FINAL
DISPOSAL
FIGURE 4.3.6. Flow Diagram for Fuel Residue Packaging Without Compaction