Radioactive materials shipments are transported by air on both short and long-haul flights, it is commonly transported by air for medical and industrials purposes either on passenger aircraft or cargo-only aircraft. Radioactive materials associated with nuclear industry are exclusively transported by road and rail or sea. Strict regulations by ICAO international civil aviation organization define how Radioactive materials shipments are safely transported by air.
In this article, I will explain how radioactive materials shipments are safely loaded in holds of passenger aircraft underneath cabin areas, and how airline's dangerous goods qualified persons apply the safe distance between radioactive materials packages and passengers and crew to protect them from unreasonable radiation exposure. Before starting explaining the process of safe loading of radioactive materials, I will answer the following three questions:
1- What is the radiation?
Radiation comes from radioactive materials is called ionizing radiation. Humans have no built-in sense with which to detect ionizing radiation, therefore, radioactive materials experts use instruments to detect it as well as to measure this type of radiation energy.
2- Can a person become radioactive from handling radioactive materials packages?
A person cannot become radioactive from the radiation being emitted from the radioactive materials packages, but they can become contaminated. No radioactivity or radiation remains in the person when he is away from the radioactive materials package. He cannot expose other people to radiation. He does not continue to be exposed himself after he moves away from the radioactive materials package.
3- How to avoid unnecessary radiation exposure?
The main methods used to avoid unnecessary radiation exposure rely on two key elements:
a- Time of explore, and
b- Distance from the radiation source
These two elements are applied by aircraft loading personnel. Safety in in handling radioactive materials is based on keeping radiation exposure as low as reasonably achievable [ by time and distance].
For safety standard regarding protecting passengers and crew the second method [ distance] is used to keep passengers and crew safe from contamination by radioactive materials radiations.
Safe Loading of Radioactive Materials on Planes
After giving you an idea about radioactive materials and its radiation, it is better for you to know about the transport index [ for radioactive materials packages], thus, will help you understand the calculation of safety distance.
The loading process is done [ By dangerous goods qualified persons] as the follows:
1- Reading the transport index for each package
Labels for radioactive material are the only dangerous goods labels which require the shipper to write some information on the label. The information is a number called (TI) the Transport Index [ only on categories II (RRY) – yellow label and III (RRY) – yellow label], which, in reality, is the highest radiation level at 1 meter from the surface of the package.
Let us see this radioactive materials ladel.
2- Referring to IATA DGR table 10.9.C to read the requirement of separation of radioactive material
The Transport Index on III (RRY) yellow label above is [ TI 2.0 ] and the number 2 , tell us that the radiation can by exposed by persons in 0.50 meters ( 50 cm). also this table tell us the minimum distance from each package or group of packages to the nearest inside surface of the partitions or floors of the flight deck or passenger cabin, or any areas occupied by other persons.
you can see this table I marked the row which give us this distance. Also IATA DGR table 10.9.C is used to separate more than one package of radioactive packages.
3- Knowing the aircraft type which will be used to transport the radioactive materials package.
In this article, I am going to explain loading of radioactive material package on Airbus 310. A310 has a lower deck holds with a proximately 1.65 m Hight [ from the hold's floor to the ceiling]. Usually, radioactive materials package is loaded on the floor of unit load devices and secured by straps. for explanation purpose I will explain on an image without unit load device.
Now, you must do small calculation process as the following:
|
|
The Height of the hold | 1.65 |
Minus
| |
The Height of the radioactive material package
| 50 cm |
Radiation distance from the surface of the package | 50 cm |
Equals | |
Safety distance for passengers and crew | 65 cm |
 |
| Safe Loading of Radioactive Materials |
Conclusion
The standard dangerous goods regulations regarding loading of radioactive materials packages are met. Safety consideration are should be taken if there are more than one radioactive materials package or other dangerous goods classes are going to be loaded on the flight.
In fact, many airlines have its specific loading regulations which are more restrictive than the actual dangerous goods regulations. also, states have its variations which are more restrictive from dangerous goods regulations.
For example, United States, Code of Federal Regulations limits the transport index and criticality safety index for radioactive materials transported on passenger aircraft as the following " Each single package on the aircraft has a transport index no greater than 3.0;". and "The combined transport index and the combined criticality index of all the packages on the aircraft are each no greater than 50.".