Fissile Material (49 CFR 173.403(j))

TM 55-315

2-15. Enriched Uranium

Enriched uranium is uranium that contains more uranium-235 than the naturally occurring distribution of uranium

2-16. Exclusive Use

Exclusive use (also called-sole use or full load) is the sole use of a vehicle by a single consignor and for which all initial,

intermediate, and final loading and unloading are carried out under the direction of the consignor or consignee. Any

loading or unloading must be performed by personnel with radiological training and resources appropriate for safe

handling of the consignment. Specific instructions for maintaining exclusive-use shipment controls must be issued in

writing and included with the shipping papers the consignor provides to the carrier.

2-17. Fissile Material (49 CFR 173.403(j))

a. Fissile Material. Any material consisting of or containing one or more fissile radionuclides. Fissile

radionuclides are plutonium-238, plutonium-239, plutonium-241, uranium-233, and uranium-235. Neither natural nor

depleted uranium is fissile material. Fissile materials are classified according to the controls needed to provide nuclear

criticality safety during transport; they are as indicated in b, c, and d below.

(1) Uranium-235 exists only in combination with various percentages of uranium-234 and uranium-238.

Fissile radioactive material, as applied to uranium-235, refers to the amount of uranium-235 actually contained in the

total quantity of uranium being transported.

(2) Radioactive material may consist of mixtures of fissile and nonfissile radionuclides. Fissile radioactive

material refers to the amount of plutonium-238, plutonium-239, plutonium-241, uranium-233, uranium-235, or any

combination thereof actually contained in the mixture. The radioactivity of the mixture consists of the total activity of

both the fissile and nonfissile radionuclides. All mixtures containing fissile material will be subject to 49 CFR 173.451

through 173.459.

b. Fissile Class I. This class consists of packages that may be transported in unlimited numbers and in any

arrangement and that require no nuclear criticality safety controls during transport. For nuclear criticality safety control, a

transport index is not assigned to Fissile Class I packages. However, the external radiation levels may require a

transport index.

c. Fissile Class II. This class consists of packages that may be transported together in any arrangement but in

limited numbers, not to exceed a total transport index of 50. For nuclear criticality safety control, individual packages

may have a transport index of not less than 0.1 and not more than 10. However, the external radiation levels may

require a higher transport index but not to exceed 10. Such packages require no nuclear criticality safety control by the

shipper during transport.

d. Fissile Class III. This class consists of packages that do not meet the requirements of Fissile Class I or II and

that are controlled to provide nuclear criticality safety transport by special arrangements between the shipper and the

carrier.

2-18. Gray (Gy)

A gray is a unit, in the international system of units, of absorbed dose which is equal to one joule per kilogram. One Gy

is equivalent to 100 rad.

2-19. Highway Route Controlled Quantity (49 CFR 173.403(1))

A highway route controlled quantity is the quantity within a single package which exceeds:

a. 3,000 times the A1 value of the radionuclides as specified in 49 CFR 173.433 for special-form material;

b. 3,000 times the A2 value of the radionuclide as specified in 49 CFR 173.433 for normal-form radioactive

material; or

c. 3,000 curies, whichever is least.

2-20. Licensed Material

Licensed material is source material, special nuclear material, or by-product material received, possessed, used, or

transferred under a general or specific license issued by the NRC.

2-21. Limited Quantity

A limited quantity is the quantity of radioactive material not to exceed the material package limits, as specified in table 4-

7 of this manual, and that conforms to the requirements of limited quantities of radioactive materials specified in 49 CFR

173.421 through 173.424.

2-22. Low Specific Activity (LSA) Material

LSA material is any of the following:

a. Uranium or thorium ores and physical or chemical concentrates of those ores.

b. Uniradiated natural or depleted uranium or uniradiated natural thorium.

c. Tritium oxide in aqueous solutions provided the concentration does not exceed 5.0 millicuries per milliliter.

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