Requirements Documentation

DOE-STD-3007-93

Shipments of radioactive waste in casks for which this evaluation is used as the basis for

criticality safety will be limited to one cask per shipment with no more than 160 FGE Pu239 per

cask. Therefore, criticality safety margins will be maintained for these shipments by controlling

the number of casks per shipment and by controlling the amount (mass) of fissile material per

cask. Compliance with the following DOE-ID and Code of Federal Regulations (CFR)

requirements will be demonstrated.

DOE-ID 5480.5A "For a system to be considered critically safe by mass alone, it

shall not have more than 75 percent of the critical mass assuming the system is in

its most reactive credible state. If over batching is credible, 45 percent of the

critical mass shall be used." (Acceptable keff values must also be # 0.95.)

10 CFR Part 71 Section 71.55(b) "...a package used for the shipment of fissile

material must be so designed and constructed and its contents so limited that it

would be subcritical if water were to leak into the containment system...so that,

under the following conditions, maximum reactivity of fissile material would be

attained:

The most reactive credible configuration consistent with chemical

and physical form of the material;

Moderation by water to the most reactive credible extent; and,

Close reflection by water on all sides."

10 CFR Part 71 Section 71.61 "A package for Fissile Class III shipment must be

so designed and constructed and its contents so limited, and the number of

packages in a Fissile Class III shipment must be so limited, that:

Twice this number of undamaged packages would be subcritical if

stacked together in any arrangement, assuming close reflection on

all sides of the stack by water; and

This number of packages would be subcritical if stacked together in

any arrangement, closely reflected on all sides of the stack by water,

and with optimum interspersed hydrogenous moderation....Each

package must be considered to have been subjected to the tests

specified in 10 CFR 71.73 (Hypothetical Accident Conditions)."

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