Frequently Asked Questions about Nuclear Transport

For what purposes are radioactive materials transported?

Each day thousands of consignments of radioactive materials are transported on international and national routes. These consignments, which are carried by road, rail, sea, air and inland waterway, are transported for a variety of applications, including:

  • medicine and health;
  • agriculture;
  • nuclear power generation;
  • advanced scientific research.

The international transport of radioactive materials is governed by a stringent regulatory regime, which includes standards, codes and regulations that have been continuously revised and updated over the past four decades.

How many shipments take place annually?

The IAEA estimates that 20 million shipments of radioactive materials are transported annually. Each shipment is made up of either a single package or a number of packages transported from one location to another. The vast majority of these shipments, some 95%, relate to non-fuel cycle transports such as the transport of smoke detectors, and cobalt sources for medical purposes. Only 5% relate to fuel cycle transports.

How is the transport of radioactive materials regulated?

The transport of radioactive materials is carefully regulated to protect people, property and the environment. The IAEA Regulations for the Safe Transport of Radioactive Material were first published in 1961 and have been revised regularly to keep pace with scientific and technological developments. Today, more than 60 Member States and the UN Model Regulations for the Transport of Dangerous Goods along with modal agencies such as the International Civil Aviation Organization (ICAO) and the International Maritime Organization (IMO) have adopted safety requirements and standards based on the IAEA Regulations. As a result, the IAEA Regulations apply to the transport of radioactive materials almost anywhere in the world.

What is 'front end' and 'back end' transport?

Nuclear fuel cycle transports are commonly designated as either front end or back end. The front end covers all the operations from the mining of uranium to the manufacture of new fuel assemblies for loading into the reactors, i.e. the transport of uranium ore concentrates to uranium hexafluoride conversion facilities, from conversion facilities to enrichment plants, from enrichment plants to fuel fabricators and from fuel fabricators to the various nuclear power plants. The back end covers all the operations concerned with the spent fuel which leaves the reactors, i.e. the shipment of spent fuel elements from nuclear power plants to reprocessing facilities for recycling, and the subsequent transport of the products of reprocessing. Alternatively, if the once-through option is chosen, the spent fuel is transported to interim storage facilities pending its final disposal.

What are nuclear fuel cycle materials?

Nuclear fuel cycle materials come in a variety of chemical and physical forms and the potential hazards they present differ widely. The underlying philosophy of the IAEA Transport Regulations is that safety is ensured principally by the package, and its design is related to the potential hazard – the more hazardous the material the tougher the package.

Uranium ore concentrate
Uranium ore concentrate is a material of low radioactivity. There is a minor risk due to the toxicity of the powder if it is released and is ingested. In this respect it is no different from most heavy metal compounds such as lead ores.

Uranium hexafluoride (Hex)
Uranium hexafluoride is also of low activity and the radiological risk is not great. However, there would be a chemical hazard in the unlikely event of a release because it produces toxic by-products on reaction with moist air.

Uranium dioxide powder (UO2)
Uranium dioxide powder for the manufacture of new uranium fuel elements is also classified as low activity material.

Uranium fuel assemblies
The fuel for the majority of nuclear reactors consists of assemblies of rods each filled with ceramic uranium oxide pellets enriched in the fissile component of uranium, U-235, to about 5%.

Spent fuel and vitrified high-level waste
Spent fuel and vitrified high-level waste are intensely radioactive and need to be heavily shielded. However they are inherently stable and, being a ceramic material, are very difficult to disperse. The solid nature of the products is one of the most important safety factors. The material is characterised by long-term stability and low solubility in water.

Mixed oxide fuel (MOX)
Mixed plutonium/uranium oxide (MOX) fuel elements, in which the enriched uranium isotope is replaced by plutonium, are very similar to uranium fuel elements and also ceramic in nature. The chemical hazard is negligible and the radiological hazard is low except in the event of a criticality excursion. This is controlled in the same way as for enriched uranium fuel i.e. by the design of the package and the configuration of the package during transport.

The primary risk is due to toxicity except in the event of criticality which is controlled by the package design.

How are nuclear materials transported?

The IAEA Regulations are based on the fundamental principle that radioactive material being transported should be packaged adequately to provide protection against the various hazards of the material under both normal and potential accident conditions. Safety, therefore, relies primarily on the package – on the packaging adapted to its radioactive contents, whatever the transport mode.

The prime objective is to protect people, property and the environment against the direct and indirect effects of radiation during transport. The requirements laid down in the Regulations must ensure the confinement of the radioactive contents, the control of the external radiation level, the prevention of a chain reaction and the prevention of damage caused by high temperature.

Because safety depends primarily on the package, the Regulations set out several performance standards in this area. They provide for five different primary packages (Excepted, Industrial, Type A, Type B and Type C) and set the criteria for their design according to both the activity and the physical form of the radioactive material they may contain. The IAEA Regulations lay down corresponding test procedures to demonstrate compliance with the required performance standards.

The Regulations also detail marking and labelling provisions, requirements imposed on packages during transit, and prescriptions for their maintenance.

How are packages and vehicles carrying radioactive materials identified?

Markings on the package detail the proper shipping name, an emergency response identification number, the shipper’s name and address and any other relevant information.

Labels are placed on opposite sides of a package to identify the contents and radioactivity level. The label is determined by the type of material shipped and radiation levels of the package’s contents. Labels also provide a hazard index to ensure correct handling. Shippers use one of three labels; Radioactive White, Yellow II or Yellow III. Shipments with extremely low levels of radioactivity are excluded from labeling requirements.

In some cases, there is also a requirement for the vehicle transporting radioactive materials to have a placard on the front, rear and sides.

What are the security requirements for nuclear transport?

Shipments of radioactive materials must comply with relevant physical protection requirements developed by the IAEA, as well as the security requirements of the Modal Organisations such as the IMO and ICAO. In addition, shipments comply with the security requirements of the shipping states’ governments.

How safe is nuclear transport?

The transport of nuclear materials is strictly regulated and has an impressive safety record spanning over several decades. No form of transport is subject to a more stringent framework of regulation. In five decades of transporting nuclear materials there has never been an incident resulting in a significant release of radioactivity. This record of success is a tribute to the effectiveness of the regulatory framework as well as the collective competence of the entities performing packaging and transport activities.