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

4.115
considered. Some facility damage and a 300-2 (80-gal) spill to the ground during a 3-hour
period are considered to be representative of the most serious results from the worst act
of sabotage (see DOE/ET-0028, p. 5.1.37).
Solidified HLW from the reprocessing cycle, which contains nearly all of the fission
products and very little plutonium, could conceivably be a target of theft for a subsequent
threat oT-dispersal of the radioactive material. However, the handling problems during
attempted theft are as formidable for HLW as for spent fuel. Heavy shielding and special
equipment are required to avoid serious radiation exposure. These factors make HLW rela-
tively unattractive for theft for any purpose, regardless of the form.
The TRU wastes would also be processed or treated in vital areas until they have been
concentrated and/or packaged so they can be transported and stored without hazard. After
packaging, the low radiation items may be stored onsite in protected, access controlled
areas. The materials in packaged form contain only small amounts of fissionable material,
and are unattractive targets for theft. Sabotage would require access to the storage loca-
tion in the plant. If sabotage is successful, the facility may be damaged and the site con-
taminated with radioactive waste. The contamination is expected to be contained with little
or no public exposure because of the plant location, site layout, and safety features.
The principal products of the example dissolver off-gas treatment facilities are the
radionuclides krypton-85, carbon-14, and iodine-129. The krypton will be concentrated and
stored as a compressed gas in cylinders and the carbon-14 and iodine-129 will be adsorbed
and packaged as calcium carbonate and silver zeolite beds, respectively.
Krypton-85, a chemically inert .gas, in the packaged form would be a concentrated radio-
active source. The dose rate at the surface of an unshielded cylinder would be about 700
R/hr when filled at the treatment plant. Remote operation in shielded storage areas will
be required to process krypton, thus reducing the availability of this waste form and making
the cylinders relatively inaccessible targets. In case of a release, the material rapidly
disperses and the threat to the health of the general public is insignifican'tf- However, a
cylinder rupture outside the facility would probably result in serious exposure to nearby
operating personnel. The massive shielding required during transport provides protection
against sabotage.
Neither carbon-14 packaged as CaCO 3 nor iodine-129 packaged as a spent silver zeolite
bed are attractive targets for theft and eventual dispersal, or for deliberate dispersal
onsite by sabotage. In these forms the carbon and iodine are nonvolatile and nonhazardous
in the amounts handled or treated in the facility, and too low in concentration to be a
health hazard to the public if released onsite as a result of sabotage.
4.10.2.2 Safeguards Requirements for Storage of Reprocessing Cycle Wastes
During the period before ultimate disposal, solidified HLW may be stored in water
basins or in surface facilities in sealed casks. Although the waste is not a source of
fissionable material, physical protection during storage must be provided to deter and pre-
vent theft or sabotage. The rationale for either theft or sabotage may be to disperse or
threaten to disperse the radioactive contents of the casks or storage facilities.