What do you mean by transporting radioactive materials?
One of several classes of hazardous materials that are transported on a daily basis throughout the United States are radioactive materials, sometimes called “RAM”. This particular discussion focuses on this practice.
Can I rely upon the information in this discussion to guide my own shipping procedures?
Absolutely not. The proper transport of radioactive materials is not a trivial issue, and mistakes can have negative ramifications. However, you can use this discussion as an overview of some of the issues and key terminology associated with RAM transport. Think of it as a starting point in your understanding of this important subject.
Why is RAM transported in the first place?
Radioactivity is used for a variety of purposes, including medical diagnosis and therapy, oil exploration, materials testing, weapons production, electric power production, consumer products, and many other applications. To take advantage of its beneficial uses, and to dispose of it when required, the RAM must, by necessity, be transported to the location of interest.
Does the transport of RAM have regulatory implications?
Most certainly! Radioactive materials cannot be shipped without proper adherence to shipping regulations. To give you an idea of how important RAM shipping is, each violation of the shipping regulations can cost shippers up to $50,000 per violation and up to $100,000 per violation in the event of death, serious injury or severe property damage.
What purpose do the regulations serve?
The regulations are important for a number of reasons, most of which involve safety. Safety is achieved by effectively containing the RAM (essential in preventing radiation and radioactive materials from negatively impacting on the environment), controlling the radiation emitted from the package, preventing a “criticality” for fissile radioactive material, and adequately dissipating any heat that is generated within the package.
Which federal agencies issue hazardous material shipping regulations in this country?
The transportation of RAM is regulated jointly at the federal level. The primary hazardous material regulations (HMR) are issued by the Department of Transportation (DOT) in Title 49 of the Code of Federal Regulations (CFR),Transportation . Title 49, Parts 171-178, contains the specific requirements for the packaging and shipment of RAM, a specific category of hazardous materials.
Is that the only federal agency?
No. The Nuclear Regulatory Commission (NRC) also has primary transportation regulations in 10 CFR Part 71, Packaging and Transportation of Radioactive Materials. To a lesser extent, 10 CFR 20.1906, Standards for Protection Against Radiation, and 10 CFR Part 61, Licensing Requirements for Land Disposal of Radioactive Waste, which applies to the siting and operation of near surface low-level waste disposal sites, contain requirements related to RAM transport. While not regulatory in nature, the NRC has also published a guidance document that is updated annually , several regulatory guides, and many information notices and bulletins on transportation issues.
Where can I find a current version of the HMR?
The DOT regulations are available through the Superintendent of Documents at the Government Printing Office (GPO) in Washington, D.C. The GPO can be reached at (202) 512-1800 or via the Internet at http://www.gpo.gov. In addition, updates to the regulations are published in the Federal Register. The Research and Special Programs Administration (RSPA) of the DOT provides amendments and proposed rulemakings through their web site at http://hazmat.dot.gov.
To what extent do the DOT regulations apply?
The DOT regulations apply broadly to the public transportation of all hazardous materials (which include radioactive materials). Shipment by all modes of transport within and between states and foreign commerce is included (i.e., rail, highway, air, and water). Also included are the methods of transport such as truck, bus, automobile, shipping vessel, airplane, rail-car, etc.
Are there any exceptions to the DOT’s authority?
Yes. Aside from the NRC, a separate government entity, the United States Postal Service (USPS), regulates postal shipments under 39 CFR Part 124, Domestic Mail Manual, U.S. Postal Service Regulations.
Why is the NRC involved?
Simply put, the Atomic Energy Act of 1954 (amended) gave the NRC responsibility for safety considerations involving the possession, use, and transfer (which includes transport) of three particular classes of RAM known as “by-product”, “source”, and “special nuclear material”. These classes of material typically require the issuance of a “license” for their possession and use.
Doesn’t this dual jurisdiction present some difficulties?
Yes, especially in the past. However, many years ago, the NRC and DOT signed a Memorandum of Understanding (MOU) wherein their respective responsibilities were clearly designated in order to minimize conflicts and overlapping requirements in the transport of RAM.
What about the various states?
Many states have entered into formal agreements with the NRC to regulate shipments involving licensed quantities of RAM. The states, in turn, have developed a consistent set of regulations to handle intrastate transport. Often they adopt the DOT regulations in their entirety.
Which organizations deal with the regulations (standards) for international shipments?
Several international organizations are involved in the transport of RAM. The International Atomic Energy Agency (IAEA) provides the primary basis for fulfilling this responsibility; however, other more recently created organizations include the International Civil Aviation Organization (ICAO), the International Air Transport Association (IATA), and the International Maritime Organization (IMO). The ICAO and IATA regulate the transport of RAM by air, while the IMO regulates ocean vessel transportation.
How comparable are the DOT and NRC regulations relative to the IAEA’s?
Regulations issued in this country essentially conform to those of the IAEA, although some exceptions and differences do exist.
What if I choose not to follow the federal regulations when shipping RAM?
Not a good move! The DOT and NRC both have enforcement policies which may result in civil or criminal penalties, cease and desist orders, suspension orders, and other highly unpleasant enforcement actions. In short, the regulations must be adhered to just like any other law.
Does anything that is radioactive have to be shipped as RAM?
No. In the context of transportation, radioactive materials are defined as those materials which spontaneously emit ionizing radiation and have an activity concentration and a total consignment activity that exceeds the values in the table in 49 CFR 173.436. Anything that contains lesser concentrations of radioactivity can be shipped without regard for the DOT regulations.
So, if I want to ship something with less than the activity concentration in that table, I can do so using any procedures I want?
As long as the radioactivity is essentially uniformly distributed through the total mass of material being shipped, and as long as you are confident that it is below those values, the DOT does not consider it to be radioactive. Therefore, it is “exempt” or not regulated for transport by the DOT or NRC.
When I look at the DOT regulations, I don’t see an exemption in units of “microcuries per gram”.
That is because the regulations issued by the IAEA in 1985 and subsequently adopted by the DOT, utilize the International System (SI system) as the controlling radiological units for transportation. Therefore, the unit for radioactivity in the SI system, the “becquerel”, takes precedence over the “curie”, the traditional unit of radioactivity. (The “Tool Box” section of the Plexus-NSD web page gives you conversions from becquerels to microcuries, and vice versa.)
What units are used when radiation levels, rather than activity levels, are reported?
Once again, the SI system takes precedence. Therefore, in this instance, dose rates are reported in sievert per hour (Sv/hr). The traditional unit is the rem per hour (rem/hr).
Does the use of the SI units pose any problem for RAM shipments in the United States?
As you might imagine, it does. The United States has been slow to respond to the international community’s widespread use of SI units. While the traditional units may still be used for a limited period of time, permanent changeover to the SI system is forthcoming. From a safety standpoint, it is very important that companies performing RAM shipments in this country understand and are “literate” in SI units in order to effect proper radiological packaging and controls.
Why is proper RAM packaging so important?
Proper packaging is a fundamental and essential component of transportation safety. The intent is to create a barrier between the environment and the radioactive material.
What parameters influence the choice of packaging as it affects safety?
Proper packaging requires knowledge of the radionuclides involved, quantity (amount) of radioactivity to be shipped, and the “form” of the radionuclide(s).
Where do I find out something about the amounts?
Title 49 (Part 173.435) has a table that lists several hundred radionuclides and associated so-called “A1” and “A2” values.
What is this A1 and A2 business all about?
Not only does a shipper have to know what radionuclide(s) it is transporting, but the quantity limits for those radionuclides as well. The A1 and A2 categories were developed to establish the maximum amount (activity) of a radionuclide that may be transported in a Type “A” package These categories replaced what was formerly called the “transport group” designation. Every radionuclide is assigned an A1 and A2 value.
So what is the difference between A1 and A2?
“A1” is the maximum amount of activity for a particular special form radionuclide that is allowed in a Type A package, while the “A2” designation is the maximum amount of activity that can be transported in a Type A package for normal form materials. (As you might suspect, “normal form” materials are those that are not classified as “special form”.) A special form material is a single solid piece or a sealed capsulecontaining radioactive material that can only be opened by destroying the capsule, thus it is certified as being special form.
So what do A1 values really represent?
A1 values represent conservative (worst case) assumptions regarding external gamma radiation levels from an unshielded source at a known distance. In general, the A1 value for a particular radionuclide is defined as the quantity of that radionuclide resulting in a dose rate of 0.1 Sv/hr (10 rem/hr) at a distance of one (1) meter from the package. The key points are that A1 values apply only to special form radioactive materials and to direct radiation concerns. In addition, since external radiation is the only concern, the assumption is made the radioactive materials inside the package will not be dispersed if the package is damaged.
And the A2 designation?
The A2 value also looks at worst case assumptions, but takes into account five exposure pathways rather than just one. These are external gamma radiation, external beta radiation to the skin, inhalation, ingestion, and external gamma radiation from immersion in a gaseous cloud of radioactive material released from a package which has been breached (i.e., a loss of package integrity). The key points here are that A2 values apply to normal form RAM and to both external and internal exposure concerns. Unlike the A1 designation, the assumption is made that dispersal and contamination of the package contents is probable if the contents were inadvertently released. If you look closely at the two lists, you will see that an A2 value for a particular radionuclide can be equal to its A1 value, but it cannot exceed the A1 value.
This sounds a little bit confusing to me!
That’s perfectly understandable. Hang in there! Shipping radioactive materials requires a working knowledge of many separate issues, including at a minimum, definitions and the appropriate transport regulations (domestic versus international). Often, further interpretations of these regulations from individuals experienced in shipping RAM is necessary. Just keep in mind that the A1 and A2 values were developed as a means of normalizing the radiological risks for all radionuclides that might be shipped.
Maybe some examples would help me see what you mean.
Good idea. Let’s start first with the man-made radionuclides Cesium-137 (Cs-137) and Cobalt-60 (Co-60). The A1 (special form) limit for Cs-137 is 2 TBq or 54Ci, while the A2 (normal form) limit is considerably lower; only six tenths (0.6) TBq (16 Ci). For Co-60, the A1 and A2 values are exactly the same – 0.4 TBq or 10.8 Ci each. For Co-60, we can assume that even if five rather than one exposure pathway is taken into account, there is no greater risk than if only one pathway is considered. Hence, the A1 and A2 values are identical. This is not the case for Cs-137 where the risks differ depending upon the exposure pathway(s).
What do you mean by “special form” materials?
First, remember that the special form designation applies to A1 limits only. This designation pertains to those materials which, if released from a package, would present a hazard solely due to external radiation. So, the form of the radioactivity must be one that would not create exposure conditions via other pathways.
Can you give me an example?
Sealed (encapsulated) sources of radiation, much like those found in a smoke detector, are “special form” materials. Because higher radioactivity limits are permitted, durable metal capsules with a high physical integrity ensures that the radioactivity therein will not disperse. In addition, only solid materials can be classified as “special form”.
Special form encapsulation is designed so that the capsule cannot be opened unless the capsule is destroyed. In other words, no mechanism exists for opening or loosening the capsule in a manner that could inadvertently release its contents. Special form capsules also undergo rigorous testing described in Title 49 before they receive that classification. These include tests for temperature, impact, percussion, bending, and leakage.
What other types of sources can qualify for special form designations?
There are several types of sources that satisfy the criteria for shipment as special form. Examples include neutron sources, density/transmission sources, industrial radiography sources, and sources used for sterilization and processing. A copy of a source’s certification as special form must be maintained on file by owners and users of these sources if they intend to transport them.
What can you tell me about “normal form” radioactive materials?
As mentioned previously, A2 limits apply to normal form materials. These materials are referred to as “non-special” form, or materials that do not qualify as special form materials as defined in 49 CFR 173.403.
What’s so different about them?
Unlike special form materials, normal form materials may be solid, liquid, or gaseous and include any material which has not qualified as special form. Examples might be waste material in a plastic bag, a liquid-containing bottle housed within a metal container, powder in a glass or plastic bottle, contaminated soil in a 55 gallon drum, or a gas inside a cylinder.
When is a Type “A” package required for shipping RAM and what do you mean by a Type “A” quantity?
A Type “A” package may be required when the radioactivity inside the package does not exceed an A1 or A2 value. A Type A package cannot be used if an A1 or A2 value is exceeded since it is designed to withstand normal transportation conditions and minor accidents only. A Type “A” quantity is a quantity of RAM that does not exceed the A1 value for special form shipments or the A2 value for normal form in a single package.
Under what situations is Type “A” packaging used?
There are several situations where Type A packaging would be utilized. Examples might include shipments of radionuclide generators for medical diagnosis and treatment, moisture density gauges, and radionuclides in liquid form for medical or research purposes. Type A packaging includes, but is not limited to, cardboard, wooden and “ammo” boxes, as well as steel drums. The intent of a Type A package is to prevent loss or dispersal of the package contents while still maintaining proper radiation shielding under normal transportation conditions.
Is testing of Type “A” packaging a prerequisite prior to use?
Most certainly. Type A packages are designed to withstand rough handling conditions. To do so, they must successfully pass a variety of tests including water spray tests (to simulate the effect on the packaging under wet weather conditions), drop tests, puncture tests, and crush tests. Performance requirements for liquids and gases are even more stringent than those for solids.
When is a Type “B” package required and what is meant by a Type “B” quantity?
This type of package is required when the radioactivity to be shipped exceeds an A1 or A2 value. Type B packages must therefore meet all the requirements for Type A packaging. But they must also have the ability to withstand serious accident conditions with no subsequent loss of containment and limited loss of shielding capability. The latter requirement dictates that the packaging be subjected to a much greater level of testing. A Type “B” quantity is a quantity of RAM which exceeds the Type A quantity limits in a single package.
Can you provide examples of Type B packaging?
Yes. Wide ranges in the physical package types exist. Examples include packaging for industrial radiography exposure devices (small) to waste casks and spent nuclear fuel casks (large).
How much more stringent is the testing?
Well, for example, instead of surviving a four (4) foot fall onto a hard surface, the case for Type A packages, Type B packages are dropped from a height of thirty (30) feet onto an unyielding surface. These packages are also exposed to a severe temperature environment (800 degrees centigrade) for thirty (30) minutes and water immersion to a depth of at least fifteen (15) meters – conditions Type A packages are not subjected to. There are other tests as well. In short, Type B packages are extensively tested prior to use to provide confidence that structural integrity is maintained during radioactive material transport of higher activity materials.
How do I know if my package is a Type B package?
Not only must it pass all of the tests, but it must be “certified” as a Type B package. The NRC and the DOE, through authorizations provided by the DOT will “certify” all Type B packages for use by issuing a “Certificate of Compliance”.
Where can I find more information about Type B certifications?
A very useful source is NUREG-0383, Directory of Certificates of Compliance for Radioactive Materials Packages. This document is issued annually by the NRC in a three volume set. It includes a list of authorized users and approved packages, Certificates of Compliance, and approved quality assurance programs for RAM packages.
I’ve heard the term “Highway Route Controlled Quantity” before. Is that the same as an A2 quantity?
No. The Highway Route Controlled Quantity (HRCQ) refers to RAM shipments of high radioactivity levels, typically greater than 3000 times the A1 or A2 limits (i.e., 1000 TBq or 27,000 Ci), that not only require Type B packaging, but certain highway routing limitations and requirements.
In what other way are A1 and A2 values utilized in the transport of RAM?
Fractional multiples of the A1 and A2 (i.e., values less than their respective limits) are used to set limits for other categories of RAM. These are called “limited quantities”, “excepted articles”, and “LSA materials”.
What are limited quantities?
A limited quantity is a shipping classification for RAM that allows packages with a low amount of radioactivity inside to be exempt from most DOT shipping requirements.
What is meant by “strong, tight packaging” or “excepted packaging”?
“Strong, tight packaging” or “excepted packaging” refers to packages which contain radioactivity of a very limited hazard due either to its small amount or low concentration. The package is designed to contain and protect the contents during normal shipping activities. An example where this type of packaging is put to good use on a regular basis is during the transport of smoke detectors. This commonly used, and very important consumer product contains an “exempt” or limited quantity of Americium-241 (Am-241). Therefore, they are typically shipped in excepted packaging.
What are the requirements for excepted packaging?
There are several requirements which must be satisfied. Title 49 of the CFR supplies the specific details. In general, the removable contamination limits must not be exceeded, certain radiation exposure rate limitations must be met either on the package itself or the surface of the unpackaged instrument/article, “radioactive” markings must be affixed to the package in an appropriate fashion, and the UN identification number must be on the package.
This seems like a lot of rules. Is there a logical way of evaluating them in order to determine the type of packaging required.
Well, let’s try this. Start first with the basics, then work your way to the more complicated. Remember first there are materials that are not regulated in transport because they do not meet the definition of radioactive material (i.e., radioactivity less than the concentration shown in 49 CFR Table 173.436). Once you have determined that your package is indeed radioactive, it is packaged in the following hierarchy (from least radioactive to highest radioactivity content): excepted package (i.e., for limited quantities and excepted articles) which is on the order of 1,000 – 10,000 times less than the A1/A2 values; Type A package (i.e., for Type A quantities) which can contain RAM up to the A1/A2 values, and Type B package (i.e., for Type B quantities) which can contain RAM exceeding the A1/A2 limits. There are also packages known as Industrial Packages (IP) that are sometimes used to ship Low Specific Activity (LSA) materials.
You mentioned the term “transport index” before. What does it refer to?
Good question! The transport index or “TI” has been used for many years. It is defined as the radiation exposure rate, in units of millisieverts per hour (mSv/hr) (or millirem per hour if multiplied by 100) at a distance of one meter from the external surface of a package containing radioactivity. It is a dimensionless number which is identified on the label of a package so that the carrier or other interested parties can quickly assess the relative radiation hazard and the corresponding degree of control to be exercised during handling.
Would you give me an example of a transport index?
Sure. If the exposure rate at one meter, or about 3.3 feet, from a package is 5.0 mrem/hr, the TI is 5.
I’ve also heard the term “exclusive use” vehicles before. What are those?
Exclusive use infers that RAM packages, once loaded on the vehicle, remain on that vehicle until the final destination is reached. No additional loading or unloading occurs while the vehicle is in transit. Specific instructions detailing unloading and shipment maintenance procedures are provided to the transporter and to the package recipient.
Are there maximum permissible dose rates for packages shipped in a non-exclusive use vehicle?
Yes there are. Typically, two limits have to be met. First, there must be a maximum of 200 mrem/hr at any point on the package surface. Second, the dose rate cannot exceed 10 mrem/hr at one (1) meter from the package. (The latter figure is reduced if the package is placed on a passenger-carrying aircraft.) There are additional requirements as well which have to do with the total transport indexes associated with a group of packages and the separation distance between packages.
Are the dose rate limits different if an exclusive use vehicle transports the package?
Yes. But the situation is more complicated because several exclusive-use vehicle scenarios exist. For example, if a package is carried on a “conventional, closed, exclusive use vehicle”, meaning the package is inside the vehicle and inaccessible to members of the general public, the following maximum limits apply: 1000 mrem/hr on the package surface; 200 mrem/hr on all sides, top, and bottom of the vehicle; 10 mrem/hr at two (2) meters from all surfaces of the closed vehicle; and two (2) mrem/hr in the driver’s compartment. If the vehicle is an “open” flatbed vehicle where access to the package is restricted or unrestricted, the limits change. If unrestricted access is the case, the 1000 mrem/hr limit is reduced to 200 mrem/hr in order to address additional radiological safety issues..
It can be. The point is not to bore you with numbers and scenarios, but rather to demonstrate that much thought goes into the radiological safety aspects of these shipments. A variety of issues must be constantly addressed including the type of vehicle used to ensure radiological over-exposures do not occur.
You have emphasized dose limits on or from radioactive packages. Are there contamination limits as well?
Yes. The contamination of concern applies to removable (non-fixed) contamination on the surface of the package. For beta/gamma emitters and so-called “low toxicity” alpha emitters, the limit is 0.4 Bq over an area of one (1) square centimeter (cm2), which is equivalent to 2,200 disintegrations per minute (dpm) per 100 cm2. All other alpha emitters have limits which are a factor of ten (10) lower. These particular limits apply to transport in non-exclusive use vehicles. Separate limits apply under exclusive use transport and other situations.
Why is removable contamination a concern?
Removable or transferable radioactivity can be tracked or spread from one location to another. For example, a leaking package could contaminate other nearby packages or be spread by walking from one location to another, including from the workplace to the home. Removable activity can also be inhaled, representing an internal dosimetry concern.
How are contamination surveys performed?
The amount of removable activity is determined by taking a wipe or smear over the defined surface area. The smear is then counted with calibrated instrumentation, the results (in counts per minute) converted into disintegration rates, and the findings compared to the applicable regulatory limits.
Are all radioactive materials destined for transport packaged in the same way?
No. The type of packaging actually selected is dependent upon the classification of RAM to be shipped. For example, limited quantities and excepted articles require Excepted packaging, while Type A quantities require Type A packaging, Type B and Highway Route Controlled Quantities require Type B packaging. There are other examples as well.
What is fissile material?
As defined by the DOT in Title 49, fissile material refers to Plutonium-238 (Pu-238), Plutonium-239 (Pu-239), Plutonium-241 (Pu-241), Uranium-233, Uranium-235 or any combination of these radionuclides. These elements can “fission”, or split apart, if in the presence of neutron radiation.
Why is this material a concern in RAM transport?
The transport of fissile materials requires an assessment of not only radiological safety (i.e., containment of the material), but nuclear safety (i.e., criticality control). Fissile materials are always a concern in any situation due to the potential for an accidental criticality. A criticality results in the release of a large neutron and gamma ray component, sufficient to result in lethality to an exposed individual that is unfortunate enough to be in the near vicinity. For this reason, transport of fissile materials requires prudent safeguards.
How are fissile materials packaged?
Fissile materials are usually packaged as either “Fissile Type A” or “Fissile Type B” packages, although exceptions do exist. As noted previously, a Type B package, whether for fissile materials or otherwise, requires greater shielding and must pass more rigorous testing. Package certification by the NRC or the DOE is required.
Please provide some examples of materials requiring fissile packaging.
Sure. Examples include uranium dioxide powder or pellets, “fresh” (unirradiated) and “spent” (irradiated) fuel from a power reactor, uranium hexafluoride, and irradiated/unirradiated research reactor fuel.
What do the “LSA” and “SCO” classifications refer to?
LSA means “Low Specific Activity”, and SCO means “Surface Contaminated Objects”. These are two important designations involving low-to-medium amounts of radioactive waste materials.
Where do they come from?
LSA materials are generated from nuclear fuel cycle facilities as well as a wide variety of industrial, medical, research, and academic communities. The SCO category is a designation that addresses solid wastes containing radioactive contamination on the external surfaces on an otherwise non-contaminated object. SCO materials originate from cleanup, remediation, and decontamination activities.
Do LSA materials present a radiological hazard?
Yes, but to only a limited degree. This is because the designation “Low Specific Activity” indicates that not very many radiations are emitted during decays.
How are LSA materials categorized?
LSA materials are categorized into three classes known as LSA-I, LSA-II, and LSA-III.
Start first with LSA-I. When would I use this category?
The LSA-I designation is generally used for RAM with the lowest level of radioactivity. Examples include, but are not limited to, naturally occurring uranium or thorium ores or concentrates of these ores, solid unirradiated natural or depleted uranium or natural thorium, and mill tailings, contaminated earth, rubble, and other materials in which the RAM is uniformly distributed and the average specific activity does not exceed a specified limit.
What about LSA-II?
LSA-II includes water containing tritium (radioactive hydrogen) up to, but not exceeding, a specified limit, or uniformly-distributed RAM with average specific activities not exceeding specified limits for solids, liquids, and gases.
This category contains the highest specific activities of the LSA classifications. Emphasis is placed on solids which meet DOT leach test requirements; that contain radioactivity either distributed throughout the solid or essentially uniformly distributed, that contain RAM in a relatively insoluble form; and that meets specific activity requirements.
What about the Surface Contaminated Object (SCO) designation?
This designation applies to non-radioactive objects . . . that’s right – not radioactive in and of itself . . . that have radioactive contamination on their surfaces. Two categories exist, known as SCO-I and SCO-II. These categories address both fixed and removable levels of contamination on both accessible and inaccessible surfaces. The appropriate contamination limits are specified in 49 CFR. As you might suspect, higher limits apply for the SCO-II category.
Can you provide an example?
Sure. Take the situation where mostly fixed alpha contamination is present on an accessible surface. In this case, the DOT specifies a SCO-I contamination limit of 4E3 (4000) Bq/cm2 (or 0.1 µCi/cm2). For SCO-II, the corresponding limits are twenty (20) times higher (8E4 Bq/cm2 or 2.0 µCi/cm2). With knowledge of these limits, measurements of surface contamination can be taken and the results used to establish compliance. Other limits exist for non-fixed (removable) contamination and for beta radiation on accessible and inaccessible surfaces.
Are there any problems with the SCO classification system?
Unfortunately, yes. An appropriate method must be used to determine the ratio of fixed to non-fixed contamination. In addition, it is not always clear whether a surface is accessible or not. For these and other reasons, the NRC and DOT have collaborated on a guidance document (NUREG-1608) to assist in the categorization and transport of SCO’s.
How are packaging requirements determined for LSA and SCO materials?
In general, the packaging of these materials is based, as you might expect, on the potential radiological hazard of the material to be transported. In some cases, “strong tight packaging” will suffice. In other cases, Type A and “greater than Type A” packaging is necessary. In still other instances, more durable packaging (i.e., “industrial packaging”)is required such as for LSA-II and LSA-III materials, relative to the LSA-I category, due to their higher specific activities. Liquids generally require more durable packaging than solids due to the greater radiological risk from spillage. In addition, the packaging is influenced by the type of shipment (i.e., exclusive versus non-exclusive). The DOT in 49 CFR provides further information and requirements of the types of packaging needed for LSA and SCO shipments .
How are the potential hazards from the transport of RAM addressed by the DOT?
One specific approach is through compliance with 49 CFR Part 172 which describes hazardous materials (“Hazmat”) communications. Part 172 covers a diverse number of issues including appropriate shipping papers, package marking and labeling, vehicle placarding, emergency response information and Hazmat employee training.
How do I know whether a material selected for transport is a hazardous material?
Subpart B of 49 CFR 172 contains a listing of materials considered hazardous for the purposes of transportation. If your shipment is on this list, the DOT considers it to be hazardous.
Is there any other information provided with this listing?
Yes! The requirements for shipping papers, marking and labeling, and vehicle placarding are provided. In addition, the hazard class, “UN” identification number, and the proper shipping name (or where to find it) is identified.
Why are labels typically required on RAM Packages?
Labels provide a useful purpose: they alert an individual that a package contains RAM and that the package may require special handling and controls on where it is stowed and how much separation is required between packages.
What labels are typically used?
White-I, Yellow-II, and Yellow-III labels are used. A White-I label contains an all white background with the conventional three-bladed radiation symbol (the “trefoil”) in the upper half of the label and the word “RADIOACTIVE” followed by a single red stripe in the lower half. This label signifies low external radiation hazards and no special stowage or handling conditions. The appearance of a yellow color on the upper half of the label with two vertical red stripes (Yellow-II) indicates that external radiation levels from the package are sufficiently high to warrant stowage considerations. A package bearing a yellow label with three red stripes (Yellow-III) signifies still higher radiation levels and the vehicle must then be placarded “RADIOACTIVE”.
How do I know which label to choose?
There are two principal criteria: The maximum dose rate at the surface of the package and the transport index.
What are hazard classes and where does radioactive material fall under?
Hazard classes are part of the classification system found on a placard, label or shipping paper which defines the type of material being carried in transport and the associated hazard. In order, Hazard Class 1 applies to explosives, Class 2 to gases (flammable, nonflammable, poisonous, corrosive), Class 3 to flammable liquids, Class 4 to flammable solids, Class 5 to oxidizers and organic peroxides, Class 6 to poisonous and infectious materials, Class 8 to corrosives, and Class 9 (miscellaneous). RAM is classified as a Class 7 hazard.
What do you mean by “proper shipping name”?
Part 172 lists several commonly used and proper shipping names. The word “proper” simply means that the designation is acceptable for the purposes of RAM transportation. Each designation usually begins with the word “Radioactive Material” and ends with the United Nations or “UN” number. Examples include “Radioactive Material, excepted package – limited quantity of material — UN 2910” or “Radioactive Material, low specific activity — UN 2912” or “Radioactive Material, Type A package, special form, UN333”, or ….. (you get the idea).
Is it always clear which shipping name to use?
Not in all cases. However, the intent of 49CFR172.101(c)(11) is to provide assistance in this regard.
There are less frequently encountered proper shipping names for radioactive materials which pose a greater hazard from a secondary hazard than from the radioactivity itself. For example, you may encounter the designation “Pyrophoric metals, m.o.s., with a UN 1383 designation for pyrophoric thorium. This material has a low specific activity and consequently poses a low radiological hazard; however, under the proper conditions, it can catch on fire. There are several other examples as well.
Why do you keep referring to shipping papers? Are they always necessary?
Most of the time. A complete and correct description for a shipment of hazardous materials is vitally important – not only to the carrier and the recipient, but to emergency response personnel in the event of an accident. Having said that, the list of required items on the shipping papers is rather extensive.
What goes on shipping papers?
Items that must appear include, but are not limited to: the proper shipping name, the UN hazard class and identification number, the letters “RQ” if the shipment is a “hazardous substance”, emergency response telephone numbers, the words “radioactive materials” (unless these words are already contained in the proper shipping name), the name of each radionuclide in the material, a description of the physical and chemical form of the material, the radioactivity content, the radioactive label on each package (i.e., White I, Yellow II, and Yellow III), and appropriate group notations for shipment of LSA or SCO materials (e.g., LSA-I, SCO-II, etc.). Please be aware this list is not complete and that qualifying comments apply to some of the listed items.
Are there any exceptions to the requirement for shipping papers?
Yes. Excepted packages meeting certain DOT requirements are exempted from providing this documentation.
What type and level of training is required to package and ship RAM?
Employees who transport hazardous materials, i.e., “Hazmat Employees”, must be trained and tested pursuant to the requirements of 49 CFR 172, Subpart H. The essential training categories specified by the DOT are general awareness/familiarization training, function-specific training, and safety training. Initial training is required within a specified time frame (90 days) for new employees assigned to a specific job. Recurrent training is also required within three (3) years (or 90 days for employees assigned to a new job for which they have not been previously trained). Records must be maintained attesting that training and testing requirements have been met.
I guess training is always good, but is all this really necessary?
It is estimated that over 4 million RAM packages are transported annually in the United States. While an excellent safety record has been achieved over the past fifty years, which corresponds to the advent of the nuclear age, this is due in large part to effective training in the proper packaging of these materials.
Are there other reasons?
Yes. Radiation and radioactivity have negative connotations for many people. Effective training and adherence to the regulations has resulted in no known deaths or serious injuries to transportation workers, emergency services personnel, or the general public. It is important that this track record be maintained to promote confidence and a feeling of safety among the populace.
What is the most important lesson in this discussion?
Actually, there is more than one. Radioactive material is transported on a daily basis in the United States by rail, truck, water, and air. Safe transport of these materials is based primarily on the use of proper packaging. While there are risks associated with the transportation of RAM, namely the risks from a vehicle accident and the associated radiological ramifications, these risks have been demonstrated historically to be quite low. When they occur, emergency response plans exist and are implemented by trained personnel to respond appropriately and in a timely fashion. However . . .
Adhering to the shipping regulations can be easier said than done. While we presented some general terminology and some examples in this discussion, it is important that experienced and trained individuals who know and understand all of the twists and turns of the regulations be involved in the packaging and transport of your radioactivity or radiation source. History has shown, over and over again, that a tentative or flippant attitude to shipping always comes back to haunt the shipper. And by the way, the “I didn’t know what you meant” excuse gets you nowhere . . . fast.