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

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intrusion or sabotage would be required. The dose rate at the surface of an unshielded
krypton cylinder would be about 700 R/hr when received from the reprocessing plant. A
remote and shielded storage area will be required for storage, thus reducing the availabil-
ity of this waste form and making the cylinders relatively inaccessible targets.
It is possible for acts of sabotage to rupture a cylinder of krypton during the
receiving or internal transfer operations. The consequences to the public from such acts,
however, would be small because the storage buildings are designed to allow the release of
krypton through high stacks only. Approximately 104 KCi of krypton-85 might be released
over a half-hour period. Such a release could result in significant exposure of workers in
the vicinity of the rupture.
Successful sabotage of the krypton storage cell does not appear credible. The cell
walls, at least two feet thick, are built of reinforced concrete. However, if the walls are
breached by an act of sabotage and krypton is released at ground level, the consequences to
workers in the immediate area could be serious but the consequences to the public would be
small.
4.10.2.3 Safeguards Requirements for Transport of Reprocessing Cycle Wastes
Solidified high-level wastes will be shipped in casks designed specifically for this
purpose. A shipment of HLW will contain more fission product activity but less than 1% of
the plutonium included in a shipment of spent fuel. Physical protection requirements for
shipments of solidified high-level wastes have not been established by the regulatory
agencies. The actual level of physical protection required for shipments of solidified
high-level wastes will likely be based on the experience of successful shipments of spent
fuel.
Shipping casks as currently conceived, with designs based on the cask criteria for
shipping spent fuel, offer significant protection against assault and attempted removal of
the contents. A cask would weigh about 90 metric tons, with a special cask cover weighing
about one metric ton and requiring special equipment to remove. The cask would be resistant
to small arms fire. Explosives in sophisticated designs and arrangements could penetrate a
cask. However, the consequences of penetration of a cask would be a minor release of radio-
active material at the site (DOE-ET-0029, Vol. 2, p. 8.1.5).
The packaged TRU wastes would be relatively unattractive to an adversary because of its
high and varied dilution of radioactive materials. No container or single shipment would
contain more than 40 grams of plutonium, and the material, when immobilized in concrete or
bitumen or in some other non-dispersible form, would not be a threat to the public as a dis-
persible radioactive contaminant. If sabotage of a shipment occurs, the release of radioac-
tive materials even under severe conditions is expected to be small (DOE-ET-0029, Vol. 2,
p. 8.1.5).