Greeting....
Every day, the lives of hundreds of millions of Americans are improved by the energy of the atom. Serious
diseases are diagnosed and treated. Products from airplanes and bridges to soft drinks and aerosol cans
are tested for safety and quality.
To provide these benefits, radioactive materials must be shipped from one location to another. Shipments
of radioactive materials have been made with an excellent record of public safety — because of the
care taken by the companies involved and the government agencies which regulate them.
The Department of Transportation and the Nuclear Regulatory Commission are the primary agencies issuing
regulations based on the standards developed by the International Atomic Energy Agency.
The Nuclear Regulatory Commission and the Department of Transportation share responsibility for the
control of radioactive material transport. Department of Transportation regulations are detailed and
cover all aspects of transportation, including packaging, shipper and carrier responsibilities,
documentation, and all levels of radioactive material from exempt quantities to very high levels.
NRC regulations are primarily concerned with special packaging requirements for larger concentrations of
radioactivity.
For transportation purposes, radioactive material is defined as any material which has a specific
activity greater than 0.002 microcurie per gram. This definition does not specify a quantity, only a
concentration. [Show Radioactive Symbol.]
Recognizing that transport accidents can happen even under the strictest safety requirements, the
regulations are designed to insure safety in routine handling situations and to insure packages for the
most hazardous radioactive materials will remain intact under severe accident conditions.
These goals are accomplished by focusing on the package and its ability to:
- contain the material (prevent leaks)
- prevent unusual occurrences (such as criticality)
- reduce external radiation to safe levels (provide shielding)
Today, we're going to talk about the shipment of used (spent) fuel. When shipping used fuel from
nuclear power plants, special care is taken to prevent any release of radioactivity to the environment
even under the worst imaginable accident conditions.
Spent fuel is shipped in heavy casks that weigh from 20 to 100 tons. Different casks are used for
different modes of transport (truck, barge, train), but all must pass a series of severe tests in
succession:
- being dropped from 30 feet onto reinforced concrete
- being dropped from 40 inches onto a steel spike
- being burned in a hot fire for 30 minutes
- submersion in water for eight hours
These tests are designed to mimic the forces a transport package would endure if it collided with an
immoveable object, then fell onto a spike, then burned in a gasoline fire, than fell into a body of
water. They are carefully monitored and measured with high-speed cameras. The tests help engineers and
scientists better understand how these containers would respond to conditions that simulate an accident.
The results can help them revise their designs, if needed, and demonstrate to the NRC that their
packages meet safety regulations.
To provide confidence that meeting the regulatory requirements means a package will perform safely in a
real accident, spent fuel casks have been tested under real and possibly extreme accident conditions.
For example, in one test a truck carrying a cask crashed into an unyielding cement wall at 85 miles per
hour and in another test a cask was broadsided at 100 miles per hour by a 140-ton locomotive pulling
three railcars. In both instances, the casks were not damaged enough to leak any radioactive waste.
Let's take a close look at how the spent fuel is prepared for shipment. First, the spent fuel
assembly from the reactor is placed inside its cask and the cask is sealed. Second, the outside of the
cask is cleaned and then measured for radioactivity. Third, the cask is loaded onto the truck or train
car that will carry it.
However, before shipping can begin the cask must be inspected a second time to make sure that it is
properly installed on the vehicle. Finally, the spent fuel cask and the vehicle carrying it must both be
labeled.
In addition to all the requirements that casks must meet to be shipped by truck, the truck driver must be
trained in the hazards of radioactive materials, transportation regulations, and emergency procedures.
The route the truck will take is also given careful consideration to avoid large cities and undesirable
road conditions. And special security requirements ensure the cargo will be adequately protected along
the entire route.
No matter what type of radioactive material is being shipped, how it is packaged is the most important
consideration. The three basic types of packages are strong tight containers (STCs), Type A containers,
and Type B containers. While the characteristics of STCs are not specified by regulation, types A and B
have very specific requirements listed in the Department of Transportation regulations.
An STC is designed to survive normal transportation handling. In essence, if the contained material makes
it from point A to point B without being released, the package is classified as being a strong tight
container.
A Type A container, on the other hand, is designed to survive normal transportation handling and minor
accidents. Type B containers must be able to survive severe accidents.
Fissile materials (spent fuel) that could be involved in a criticality accident also have additional
packaging requirements.
Markings on packages, labeling, and placarding on transportation vehicles are also important aspects of
the transport of radioactive materials. Markings are designed to describe the contents of a package by
using standard terms and codes. [Show "Markings"]
Labels are used to visually indicate the type and level of hazard contained in a package. Labels rely
principally on symbols to indicate the hazard. [Show "Labeling"] Although the package required for transporting
radioactive material is based on the activity INSIDE the package, the label required on
the package is based on the radiation hazard OUTSIDE the package.
Radioactive material is the only hazardous material that has three possible labels, depending on the
relative radiation levels on the outside of the package. Also, labels for radioactive material are the
only ones that require the shipper to write some information on the label. The information is a number
called the Transport Index (TI), which is essentially the highest radiation level at one meter from the
surface of the package.
The three labels are commonly called White I, Yellow II, and Yellow III, referring to the color of the
label and the roman numeral prominently displayed. A specific label is required if the surface radiation
limit and the limit at one meter satisfy the requirements shown on the "Labeling"
transparency.
Placards are just bigger labels that are placed on the outside of the vehicle. Unlike labels, there is
only one placard and no information need be written on it. [Show "Placarding"] Placards on a vehicle are only required if the
vehicle is carrying a package bearing a Yellow III label or low specific radioactive material.
The outstanding safety record of storing and shipping used fuel is no accident. It is the result of a
philosophy that places public safety and environmental protection first, and a practice of controlled
handling and packaging of the used fuel so that it cannot harm the workers, the public or the
environment.
Answers to Questions from Transportation of Radioactive Materials Unit Outline:
| 1. |
Q: |
What three things are involved in transportation of spent fuel
assemblies? |
| A: |
a. |
a series of tests to make sure the casks that will be used really work |
| b. |
careful loading and inspection for proper installation of the spent fuel cask |
| c. |
training of the truck driver on the hazards of radioactive materials, transportation
regulations, and emergency procedures. |
| 2. |
Q: |
What are the tests required for transport packages for the most
hazardous radioactive materials? |
| A: |
a. |
30-meter drop onto an unyielding surface |
| b. |
40-inch drop onto a steel spike |
| c. |
a 30-minute hot fire |
| d. |
submersion in water for eight hours |
| 3. |
Q: |
Name the primary organizations that develop rules governing transport of
radioactive materials |
| A: |
a. |
The International Atomic Energy Agency |
| b. |
Department of Transportation (DOT ) |
| c. |
Nuclear Regulatory Commission (NRC) |
| 4. |
Q: |
How is radioactive material defined for transportation
purposes? |
| A: |
It is defined as any material which has a specific activity greater than 0.002
microcuries per gram. This definition does not specify a quantity, only a concentration.
|
| 5. |
Q: |
What are the three basic types of packages used to transport radioactive
materials? |
| |
A: |
a. |
Strong tight containers (designed to survive normal transportation handling) |
| |
|
b. |
Type A containers (designed to survive normal transportation handling and minor accidents)
|
| |
|
c. |
Type B containers (able to survive severe accidents) |
| 6. |
Q: |
Why are labels and markings used on packages containing radioactive
materials? |
| |
A: |
Labels are used to visually indicate the type of hazard and the level of hazard
contained in the package. Markings are designed to provide an explanation of the contents of
a package by using standard terms and codes. |
