Thermal Limits (49 CFR 173.442)

TM 55-315

or on any for-hire motor vehicle carrying passengers, except where no other practicable means of transport are available.

If passenger-carrying motor vehicles are used, packages of radioactive materials must be stored only in the truck or

baggage compartment of the vehicle, not in any compartment occupied by persons. Packages of radioactive materials

must be handled and placed in the vehicle as prescribed in paragraph 11-12 of this manual (49 CFR 177.842). The

maximum gross weight of the shipment will not exceed 100 pounds (49 CFR 177.870).

b. Transport Vehicles (49 CFR 173.459). Except as provided in c and d below, a transport index of not more than

50, determined by adding the transport indexes shown on each package, may be shipped in any transport vehicle (para

2-47 and 49 CFR 173.459 (a)). Mixing of Fissile Classes I and II packages is permissible.

c. Exclusive-Use Vehicle (49 CFR 177.842 and 49 CFR 1 73.459(c)3). A transport index of not more than 50 may

be transported in an exclusive-use vehicle. However, under the conditions prescribed in 49 CFR 173.457 and the

provisions of paragraph 4-14 of this manual, the transport index for nuclear criticality control purposes shall not exceed

100 for all packages in a shipment.

d. Exclusive-Use Closed Transport Vehicles. Packaged radioactive materials may be shipped in an exclusive-use

closed transport vehicle following the restriction outlined in c above. Unpackaged (bulk) LSA materials shall be shipped

only in exclusive-use closed transport vehicles. However, bulk shipments of LSA materials are limited to the following:

(1) Uranium or thorium ores and physical or chemical concentrates of those ores.

(2) Uranium metal or natural thorium metal, or alloys of these materials.

(3) Materials of low radioactive concentration. The average estimated radioactivity concentration shall not

exceed 0.001 millicurie per gram and the contribution from materials with an A2 value of less than 0.05 curie does not

exceed 1 percent of the total radioactivity. See table 2-2 for the A2 values.

(4) Objects of nonradioactive material that are externally contaminated with radioactive material. The

radioactive material shall not be readily dispersible, and the surface contamination over a 1 square meter average shall

not exceed 0.001 millicurie per square centimeter for all radionuclides of which the A2 value is less than 0.05 or 0.001

millicurie per square centimeter of other radionuclides. Such objects must be suitably wrapped or enclosed.

3-5. Thermal Limits (49 CFR 173.442)

Each package of radioactive material shall be designed, constructed, and loaded so that:

a. The heat the radioactive contents generate within the package will not, at any time during transport, affect the

integrity of the package.

b. The temperature of the accessible external surfaces of the loaded package will not, based on still air in the

shade at an ambient temperature of 38 (100 ), exceed either:

(1) 50 (122 ) in other than an exclusive use shipment, or

(2) 82 (180 ) in an exclusive use shipment.

3-6. Limits for Transport of Fissile Class III Materials (49 CFR 173.457)

Fissile Class III materials shall be shipped to provide:

a. Nuclear criticality safety.

b. Exclusive-use conveyance if moved over public highway or rail.

c. An escort to provide administrative controls if transported by aircraft.

d. If moved over public highway, the conveyance shall have no other packages of radioactive material that must

bear one of the following labels: POISON, FLAMMABLE LIQUID, FLAMMABLE SOLID, DANGEROUS WHEN WET,

CORROSIVE, CARGO AIRCRAFT ONLY, MAGNETIZED MATERIAL, BUNG, ETIOLOGIC AGENTS, and EMPTY.

e. See paragraph 4-15 for additional details.

3-7. Limits for Transport of Mixed Fissile Material Packages (49 CFR 173.459)

Shipments of mixed fissile material packages shall adhere to the following limits:

a. The total transport index shall not exceed 50.

b. For Fissile Class II packages shipped under the exclusive-use provisions, the transport index, which is

calculated for nuclear criticality control purposes, shall not exceed 10 for any single package nor a total

of 50 for the conveyance.

c. Fissile Class II packages may be shipped with an external radiation level greater than 10 millirems per hour at

1 meter (3.3 feet). Also, they may be combined with other packages of the same or different designs in a Fissile Class III

shipment if the provisions of 49 CFR 173.459(c) are met.

d. A shipment of Fissile Class III packages may be combined with other packages of the same or different design

when each package has been assigned a transport index for nuclear criticality control purposes according to Fissile Class

II criteria, and may be combined with Fissile Class III shipment if under the provisions of 49 CFR 173.459(d).

e. For exceptions regarding shipments of fissile materials, see 49 CFR 173.453.

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