motor vehicle or water as may be necessary to effect transfer of import shipments from place of discharge to other places within the the same port area or delivery to a water carrier within the same port area (including contiguous harbors). Further transportation of such import shipments by connecting water carrier shall be subject to the regulations prescribed by the Commandant of the Coast Guard.

(b) Shipments of explosives and other dangerous articles offered for transportation by common carrier by water from the United States, its insular possessions, or dependencies, destined to such insular possessions or territory, dependencies, or to a foreign country, must be packed, marked, labeled and described in accordance with the rules and regulations in force at destination ports or as prescribed in Parts 71-78.

73.11. Violations and accidents to be reported:

(a) Consignees must report promptly to the Bureau of Explosives all instances of improper staying and broken, leaking, or defective containers of explosives or other dangerous articles in shipments received by them.

(b) The Bureau of Explosives, upon receipt of reports from consignees, should promptly report to the shipper full particulars covering all such cases.

Subpart A.-Preparation of articles for transportation by carriers by rail freight, rail express, highway, or water

73.27. Rail express limitations:

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(c) When several dangerous articles are placed in one outside package without violating the regulations, the combined quantity of any one group must not exceed the lowest limit prescribed for any one of the articles of that group that is included. 73.29. Empty containers:

(a) Empty cylinders, barrels, kegs, drums, or other containers except carboys (see paragraph (c) of this section) previously used for the shipment of any explosive or other dangerous article, as defined in this part, if authorized for reuse must have all openings including removable heads, filling and vent holes, tightly closed before being offered for transportation. Small quantities of the ma terial with which containers were loaded may remain in "empty" containers and when the vapors remaining therein are unstable, it is permissible to add sufficient inert gas to render the vapors stable.

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(e) All containers and accessories which have been used for shipments of radioactive materials when shipped as empty must be

sufficiently free of radioactive contamination so as to conform to the conditions of paragraph (a)(1), (2), and (3) of 73.392 of this part.

(f) Containers shipped as "empty" must have the old labels prescribed by this part removed, obliterated, destroyed, or completely covered by a square white label as described in 73.413 of this part, measuring not less than six inches on each side, and bearing thereon the word "EMPTY" in letters not less than one-inch high. This does not apply to carload or truckload shipments to be unloaded by consignee.

Since the use of warning labels on used containers shipped as "Empty" is prohibited, it is desirable that in cases in which the consignee may be inconvenienced by unsuspected radioactive content of such containers he should be directly informed of the shipment. Such shipments may also be entered on bills of lading or other shipping papers as "Empty containers which have contained radioactive materials." However, such description does not provide positive assurance that the information will appear on papers reaching the consignee, since in transcribing the description from one set of papers to another the carrier may shorten the description to the minimum required for tariff classification, "Empty Containers."

73.30 Loading and placarding of cars by shippers and unloading of cars by consignees:

(a) When shipments of explosives or other dangerous articles are loaded into cars by shippers, or unloaded from cars by the consignee or his duly authorized agent, the applicable provisions of Part 74 must be complied with. See 74.538 for loading and storage chart.

Subpart D.-Flammable solids and oxidizing materials;

73.226. Thorium metal, powdered:

...

(a) Thorium metal, powdered, must be packed in specification containers as follows:

1. Spec. 15A or 15B. Wooden boxes with inside metal containers, tightly and securely closed by push-in covers held in place by soldering at least at four points, or in screw-cap type metal cans. Inside containers must not exceed 10 pounds net each. Gross weight of outside packages must not exceed 75 pounds each.

Subpart G.-Poisonous articles; definition and preparation

73.391. Radioactive materials class D Poison, Radioactive materials label; definition:

(a) For the purpose of Parts 71-78 radioactive material is any material or combination of materials that spontaneously emits

ionizing radiation. For the purpose of Parts 71-78, radioactive materials are divided into three groups according to the type of rays emitted at any time during transportation, as follows:

1. Group I.-Radioactive materials that emit gamma rays only or both gamma and electrically charged corpuscular rays.

2. Group II.-Radioactive materials that emit neutrons and either or both the types of radiation characteristic of Group I

materials.

3. Group III.-Radioactive materials that emit electrically charged corpuscular rays only; i. e., alpha or beta, etc., or any other that is so shielded that the gamma radiation at the surface of the package does not exceed 10 milliroentgens for 24 hours at any time during transportation.

Since all materials are radioactive to some degree, it must be presumed that the above definition of a radioactive material is intended to apply only to materials having a history which suggests that they have a higher degree of radioactivity than is normal to materials in common usage. For example, materials which may have been subjected to a considerable quantity of activating radiation, materials which may have been contaminated with radioactive materials, or materials from mines containing radioactive ores must be considered to come under this definition unless it is known that their radioactivity is within the range of that of materials not normally considered to be radioactive.

For purposes of ICC regulations, packages of radioactive materials are classified as Group I, Group II, or Group III to facilitate the statement of regulations covering labeling and handling. Packages classed as Group I or Group II require special precautions in transit and in storage to protect personnel and photographic film from radiations emitted from the packages. The stipulation "at any time during transportation" in describing a Group III package is made necessary by the fact that the gamma radiation from some packages will increase during transit due to the formation of gamma-emitting daughter products of the radioisotope being shipped.

(b) Not more than 2,000 millicuries of radium, polonium or other members of the radium family of elements, and not more than 2,700 millicuries (disintegration rate of 100,000 million (10") atoms per second) of any other radioactive substance may be packed in one outside container for shipment by rail freight, rail express, or hignway, except by special arrangements and under conditions approved by the Bureau of Explosives or except as specifically provided in subparagraph (c) of this section.

NOTE 1.-For purposes of Parts 71-78 of this chapter, one millicurie is that amount of any radioactive material which disintegrates at the rate of 37 million atoms per second.

(c) Not more than 300 curies of solid cesium 137, cobalt 60 or iridium 192, may be packed in one outside container for shipment by rail freight, rail express, or highway, except by special arrangements and under conditions approved by the Bureau of Explosives.* Within the AEC, activities of shipments of all radioactive materials generally are measured in curies or in sub-multiples of curies. One curie is equivalent to 1,000 millicuries or to 1,000,000 microcuries. From Note 1 above, "that amount of any other radioactive substance which disintegrates at the rate of 100,000 million atoms per second" is 2.7 curies.

Paragraph 73.391 (b)* is generally interpreted as permitting the shipment of 2 curies (2 grams) of Ra226 in a single package, regardless of the fact that, as ordinarily shipped, the package would contain approximately two curies each of a number of radioactive decay products. That this was the intent of the National Research Council subcommittee formulating the original draft of these regulations, is indicated by the following statement from page 39 of NRC Publication 205: "The maximum quantity of radium whose shipment is permitted in a single container, as in a neutron source, is 2000 mc. or 2 gm. Ra.” Field comment indicates, however, that some AEC installations interpret the two curies as applying to all of the radioactive material believed to be in the package. The latter interpretation receives some support from 73.27 (b). The interpretation of this paragraph as applied to other radioactive substances, e. g., uranium, thorium, strontium 90, zirconium 95, is also controversial.

73.392. Exemptions for radioactive materials:

(a) Radioactive materials are exempt from prescribed packaging, marking and labeling requirements provided they fulfill all of the following conditions:

1) The package must be such that there can be no leakage of radioactive material under conditions normally incident to transportation.

2) The package must contain not more than 0.1 millicuries of radium, or polonium, or that amount of strontium 89, strontium 90, or barium 140 which disintegrates at a rate of more than 5 million atoms per second; or that amount of any other radioactive substance which disintegrates at a rate of more than 50 million atoms per second.

That amount of material which disintegrates at the rate of 5 million atoms per second is 0.135 millicuries; and that which disintegrates at the rate of 50 million atoms per second is 1.35 millicuries.

3) The package must be such that no significant alpha, beta, or neutron radiation is emitted from the exterior of the package and *Revised May 3, 1955.

the gamma radiation at any surface of the package must be less 10 milliroentgens for 24 hours.

(b) Manufactured articles other than liquids, such as instrument or clock dials or electronic tubes and apparatus, of which radioactive materials are a component part, and luminous compounds, when securely packed in strong outside containers are exempt from specification packaging, marking, and labeling requirements provided the gamma radiation at any surface of the package is less than 10 milliroentgens in 24 hours.

1) Switchboard or similar apparatus containing electronic tubes, of which radioactive materials are a component part, are exempt from specification packaging, marking, and labeling requirements when shipped in carload or truckload lots or when transported by private motor carrier provided the gamma radiation at any readily accessible surface of the units, when prepared for shipment, does not exceed 50 milliroentgens in 24 hours.*

(c) Radioactive materials such as ores, residues, etc., of low activity packed in strong tight containers are exempt from specifications packaging and labeling requirements for shipment in carload lots by rail freight only provided the gamma radiation or equivalent will not exceed 10 milliroentgens per hour at a distance of 12 feet from any surface of the car and that the gamma radiation or equivalent will not exceed 10 milliroentgens per hour at a distance of 5 feet from either end surface of the car. There must be no loose radioactive material in the car, and the shipment must be braced so as to prevent leakage or shift of lading under conditions normally incident to transportation. The car must be placarded by the shipper as provided in 74.541 (b) and 74.553. Shipments must be loaded by consignor, and unloaded by consignee.

Paragraph 73.392 (c) provided exemption from specification packaging, marking and labeling for shipments of packaged low activity materials by rail freight, in carload lots only, subject to the conditions given therein. Such exemption is provided independently of the general conditions for exemption from specification packaging, marking and labeling given in paragraph 73.392 (a). However, such materials are not exempt from specification packaging, labeling and marking when shipped by motor truck or by railway express unless they meet the requirements of 73.392 (a). See, for example, 77.815 (a), (b), and (c).

The term "low activity material" is not defined by the ICC. The wording of 73.392 (c) and of 74.532 (j) (1) implies that any gamma emitting material, a full carload of which does not produce radiation in excess of 10 mr./hr. at a distance of 12 feet from any surface of the car may be considered low activity material for this purpose.

*Revised May 3, 1955.