Multilateral Approval

TM 55-315

d. Material in which the radioactivity is essentially uniformly distributed and the estimated average concentration

of contents does not exceed:

(1) 0.0001 millicurie per gram of radionuclides for which the A2 quantity is not more than 0.05 curie;

(2) 0.0005 millicurie per gram of radionuclides for which the A2 quantity is more than 0.05 curie, but not more

than 1 curie; or

(3) 0.3 millicurie per gram of radionuclides for which the quantity is more than 1 curie.

e. Objects of nonradioactive material externally contaminated with radioactive material provided the radioactive

material is not readily dispersible and the surface contamination, when averaged over an area of 1 square meter, does

not exceed 0.0001 millicurie (220,000 disintegrations per minute) per square centimeter of radionuclides for which the A2

quantity is not more than 0.05 curie, or 0.001 millicurie (2,200,000 disintegrations per minute) per square centimeter for

other radionuclides.

2-23. Multilateral Approval

Multilateral approval is approval by both the appropriate competent authority of the country of origin and of each country

throughout or into which the shipment is to be moved. This definition does not imply approval from countries over which

radioactive materials are carried in aircraft, if no stop is scheduled in that country.

2-24. Nonfixed Radioactive Contamination (49 CFR 173.403(r) and 49 CFR 173.443)

Nonfixed (removable) radioactive contamination is radioactive contamination that can be readily removed by wiping a

surface with an absorbent material. Such contamination is insignificant if it does not exceed the limits specified in

paragraph 3-9 of this manual.

2-25. Normal-Form Radioactive Material

Normal-form radioactive material is radioactive material that does not qualify as "special-form radio-active material." See

paragraph 2-42 below.

2-26. Package

A package is the packaging together with its radioactive contents as presented for transport.

2-27. Packaging

A packaging is the assembly of components necessary to ensure compliance with packaging requirements. The

packaging may consist of thermal insulation, radiation shielding, and one or more receptacles, absorbent materials,

spacing structures, and devices for cooling or absorbing mechanical shocks. Sometimes, the conveyance, tiedown

system, and auxiliary equipment may be designated as part of the packaging.

2-28. Radiation Absorbed Dose (rad)

The rad is a measure of any ionizing radiation to body tissue in terms of the energy absorbed per unit mass in grams of

the tissue. One rad is a dose that corresponds to the absorption of 100 ergs per gram of body tissue.

2-29. Radiation Hazard

Radiation hazard may be divided into two categories, internal and external, depending on the location of the radiation

source with respect to the person being exposed. Internal hazard means the radiation source is inside the body; external

hazard means the radiation source is outside the body. Since all radionuclides present an internal hazard, every effort

must be made to keep radioactive material from entering the body.

2-30. Radiation Level

Radiation level is the radiation dose-equivalent rate expressed in millirem per hour (mrem/h). Neutron flux densities may

be converted into radiation levels according to table 2-1.

2-31. Radiation Types

Radioactive material produces four major types of radiation, each of which is described below.

a. Alpha Radiation. Alpha radiation is a positively charged particle emitted from the nucleus of a radio-active

atom. Physically, an alpha particle is the same as a helium atom nucleus moving at high speed. Alpha radiation is the

least penetrating of the common types of radiation (compared on the basis of the same energy), but it is characterized by

a high ionizing capability. Therefore, alpha particles represent practically no hazard outside of the body, but alpha-

emitting materials are extremely dangerous if absorbed into the body.

b. Beta Radiation. Beta radiation is a negatively or positively charged particle emitted from the nucleus of an

atom. Physically, the beta particle is the same as an electron moving at a high speed. Compared on the basis of the

same energy, beta particles are more penetrating than alpha particles but are less penetrating than gamma rays or x-

rays. Therefore, beta particles are more hazardous from outside the body than are alpha particles. Beta-emitting

materials are also extremely dangerous if absorbed into the body.

2-3