AREVA logo

The shipment of MOX fuel from France to Japan

Japan has chosen the “closed fuel cycle”, meaning one that includes used fuel recycling in the form of MOX fuel.

AREVA, the world leader in the field, has had a presence in Japan for its power company customers for over 40 years. This longstanding cooperation may be divided into three major stages.

  • The agreements signed with ten Japanese power companies in 1975 and 1978 to treat 3,000 metric tons of used fuel at AREVA's plant in La Hague (France). All of the final high-level waste produced during these operations was returned to Japan between 1995 and 2007.
  • The technology transfer agreement signed with Japan Nuclear Fuel Limited (JNFL) in 1987 for the construction of a used fuel treatment plant at the Rokkasho-Mura site in Japan and which is identical to the La Hague plant. AREVA is providing technical support to JNFL for the commercial start-up of this plant. This partnership was reinforced in June 2013 by a series of agreements signed in the presence of the Japanese Prime Minister and the President of France.
  • The fabrication of MOX fuel assemblies in the AREVA MELOX (France) plant using the plutonium separated from the used fuel treated at La Hague. AREVA signed fabrication agreements with eight Japanese power companies and has already made five shipments of MOX fuel to Japan (in 1999, 2001, 2009, 2010 and 2013). The sixth MOX fuel shipment to Japan is scheduled for the near future.

Basic schedule

  • MOX fuel for Japanese power companies is manufactured at the AREVA MELOX plant in France’s Rhône valley. The fuel is shipped to Japan in casks designed specifically for this type of shipment.
  • The casks are shipped to Japan in special ships similar to those used for shipments of used fuel and vitrified waste.
  • Upon arrival in Japan, the shipping casks are transported by road to the nuclear power plants, where the MOX fuel assemblies will be loaded into the reactors.

What is MOX?

MOX fuel contains pellets made of a mixture of uranium and plutonium oxides. The plutonium content ranges from 3 to 12%, depending on the fuel design. Used fuel processed at AREVA's La Hague plant in Normandy provides the materials needed to manufacture MOX fuel at AREVA’s MELOX plant. The MOX fuel pellets produced at the MELOX plant are inserted into metal alloy rods which are bundled into fuel assemblies.

The first step in MOX fabrication consists of mixing uranium and plutonium powders until a homogeneous blend is achieved. The blend is pressed into cylindrical pellets, which are sintered (heated) at high temperature (about 1,700°C) using a process similar to the manufacturing of ceramics. The ceramic-like fuel pellets are then inserted into fuel rods (cladding). The rods are bundled together in metallic structures to form MOX fuel assemblies.

Worldwide, 44 reactors have used MOX fuel to produce electricity since 1972. Nuclear safety authorities in the six countries using MOX fuel – Belgium, France, Germany, Japan, Switzerland and the United States – have examined MOX fuel’s behavior in power generation reactors, including in the event of a serious accident. They concluded that this fuel is as safe as “conventional” nuclear fuel made with low-enriched uranium.

Ultra secure shipments

MOX fuel assemblies are shipped in specially-designed casks licensed for transport by sea by the safety authorities in the UK, France and Japan. The TN® 12/2 cask weighs almost 100 tons and is close to six meters long and more than 2 meters in diameter. It can hold up to eight assemblies. MOX fuel is shipped aboard vessels designed specifically for the shipment of nuclear materials.

The casks, ships and logistics of these operations meet the most demanding domestic and international regulations (including the recommendations of the International Atomic Energy Agency and the requirements of the International Maritime Organization).

MOX fuel falls within the category of nuclear materials requiring stringent physical protection measures. Extensive physical measures are incorporated into the transportation plan for the shipment of MOX fuel to Japan to ensure that the ships and their cargo are protected against the threat of theft or sabotage.

Display the detail

Why is MOX fuel shipped from France to Japan?


Japan has chosen the “closed” fuel cycle. This option optimizes used fuel and waste management by treating used fuel to separate reusable uranium and plutonium from final waste, which is packaged for safe disposal.  Worldwide, 44 reactors have used MOX fuel to produce electricity since 1972.

The plutonium recovered during the treatment process is recycled into nuclear reactors in the form of MOX fuel. The use of MOX fuel offers numerous advantages:

  • plutonium offers a great energy potential ; 1 gram of plutonium produces as much energy as 1 ton of oil;
  • it reduces environmental impacts by reducing the volume and radiotoxicity of final high-level waste to be disposed of;
  • it promotes non-proliferation by reducing plutonium inventories.

Display the detail

What is MOX fuel?

Crayons de combustibles MOX

The MOX (Mixed-OXide fuel) is a nuclear fuel containing pellets made of a mixture of uranium and plutonium oxides which produces electricity. For 45 years, MOX fuel has produced more than 10% of worldwide nuclear-generated electricity.

All the reactors contain 1% of plutonium. Plutonium is considered as a raw material coming from recycled used fuels. Plutonium is an element with tremendous energy potential: one gram of plutonium produces as much electricity as more than one ton of oil.  Typically, the plutonium content ranges from 3 to 12%.

The use of MOX fuel is subject to the same safety requirements as for UOX and requires the same performances. The performance of MOX fuel is now on a par with the performance of UO2 fuel, both in terms of fabrication and operating performance.

MELOX plant - fabrication of MOX fuel - Marcoule

Display the detail

The MOX fuel fabrication process

The MOX fuel fabrication process used at AREVA’s MELOX plant includes seven stages:

• Stage 1 / Stage 2: first and second blending of plutonium and uranium oxide powders;
• Stage 3: pellet manufacturing;
• Stage 4: high-temperature sintering;
• Stage 5: rectification of the pellets to the required size with two grinding machines;
• Stage 6: insertion of the pellets into the rods (cladding);
• Stage 7: assembly of the rods into MOX fuel assemblies

More than 125 quality control procedures are carried out during the fabrication process.



MOX pellet, MOX fuel rods, MOX fuel assembly.

Mox fuel assembly

Display the detail

How is MOX fuel used in a reactor?


In France, 24 of 58 power plants can be fuelled by 30% MOX and 70% enriched uranium. MOX fuel produces more than 10% of France’s nuclear-generated electricity. A single MOX fuel assembly generates enough energy to power a town with 100,000 inhabitants for a year.

When used in a reactor, MOX fuel is comparable to uranium fuel (UO2) in terms of performance, operational use, safety, and environmental impact. Few or no modifications are required to a commercial nuclear reactor to load it with MOX fuel.

The AREVA reactor, EPRTM, was designed to use up to 100% MOX fuel.

Display the detail

Does MOX fuel present proliferation risks?

Crayons combustible MOX

In each step of the recycling process, nuclear materials are under the strict control of the national and international authorities (Euratom and IAEA).

Once recycled in MOX fuel, the civil plutonium sees its properties going away from military plutonium. It means comparing some unleaded gasoline and some fuel, or trying to fly a plane with unleaded petrol.

The United States have used technology as part of the AREVA plans to build a manufacturing plant of MOX fuel. This project is part of technology transfer signed between AREVA and the U.S. Department of Energy (DOE). Indeed, it has chosen AREVA technology to reduce a stockpile of plutonium from military and for civilian use through the MOX fuel, thus immobilizing the military declared nuclear material in excess.

Display the detail

Safeguards and non-proliferation of nuclear materials

The nuclear fuel cycle industry provides guarantees for the safeguarding and protection of nuclear materials. Before it is actually converted into MOX fuel, plutonium is stored in secure and protected buildings. These buildings are under constant surveillance by the site managers, under the strict control of national and international authorities. As for all facilities associated with the commercial nuclear power industry, MOX fuel fabrication plants are monitored by the national and international authorities, including the IAEA and Euratom. The use of MOX fuel in reactors and its shipment follow the same logic.

Display the detail

How is MOX fuel shipped to Japan?

Cask safety

Shipping casks are Type B packages meeting all established technical requirements designed to ensure the safety of operations under normal as well as extreme circumstances.

The casks undergo a series of extremely demanding tests to confirm their strength and safety. The IAEA accident conditions tests include two kinds of drop tests: a 9-meter drop onto a totally unyielding surface and a 1-meter drop onto a punch bar. The cask, including any damage sustained in the drop tests, is then subjected to an engulfing fire test for 30 minutes at 800 degrees Celsius, followed by a 200-meter immersion test.

After these tests, the cask must still be leak-tight and properly shielded to ensure that radiation doses are below internationally agreed limits.

A thorough safety assessment of these casks has been performed, showing that the safety criteria related to structural integrity, thermal performance, containment level, shielding capability and maintenance of sub-criticality are all met. This ensures the safety of the shipping casks under normal and extreme situations.

Schéma représentant un emballage de transport TN 12/2

Vessel safety features

The vessels used to ship MOX fuel assemblies and vitrified waste to Japan belong to PNTL, which is owned by INS (62.5%), Japanese power companies (25%) and AREVA through its subsidiary TN International (12.5%).

These ships are more than 100 meters long and more than 16 meters wide. Each ship carries sufficient amounts of diesel fuel to complete a journey without calling at port. They meet the international standards and requirements of the International Maritime Organization (IMO) and comply with the requirements of the Japanese Ministry of Land, Infrastructure, Transport and Tourism (MLIT) as well as the British and French authorities with jurisdiction.

With more than 5 million sea miles covered without a single incident resulting in the release of radioactivity, PNTL vessels have a safety record second to none.

The ships have several safety features:

  • a double bottom and hull to minimize damage and ensure safety in the event of accident;
  • redundant navigation, communication, power generation and cooling systems;
  • a comprehensive fire detection and extinguishing system in the event of an emergency;
  • a back-up power generation system;
  • twin engines and propellers;
  • a radiation monitoring system;
  • a satellite navigation and tracking system.

An emergency response system has also been established, with an emergency and rescue team available 24/7 in all parts of the world. 


Image International Nuclear Services/PNTL

Two vessels, sailing together, are used to ship MOX fuel from Europe to Japan. This navigation mode is part of the physical protection required under the 1988 U.S.-Japan Agreement for Cooperation Concerning Peaceful Uses of Nuclear Energy.

Display the detail

What are the physical protection measures?

Because of its nuclear characteristics, MOX fuel is placed inside the category subject to the most demanding physical protection measures.  Extensive physical measures are incorporated into the transportation plan for MOX fuel shipments to ensure that the ships and their cargo are protected against any threat of theft or sabotage.

The measures implemented meet or exceed the physical protection standards provided for in the following documents:

  • Convention on the Physical Protection of Nuclear Material (IAEA/INFCIRC 274);
  • Recommendations on the Physical Protection of Nuclear Material, published by the IAEA (AEIA/INFCIRC 225).

The authorities of four sovereign States – France, Great Britain, Japan and the Unites States – approved the conditions for these shipments, considering in particular that the physical protection system implemented ensures the necessary level of protection for the materials transported.

Display the detail

What is the regulatory framework for MOX fuel shipments?

All equipment used for to ship MOX fuel from France to Japan and all associated operations are consistent with international and national regulations.

Regulations and recommendations are set by international organizations in cooperation with Member States.  At the national level, each country adopts its own laws and regulations consistent with those of international organizations.

Nuclear material shipments must comply with two sets of stringent regulations governing the shipment of hazardous and nuclear materials respectively.

In particular:

• The sea shipment of dangerous goods must comply with the rules of the International Maritime Dangerous Goods Code (IMDG Code) issued by the International Maritime Organization (IMO).  This code offers guidance to persons involved in the handling and transport of radioactive materials in port facilities and on ships. It describes all of the provisions to be complied with in terms of packaging identification, marking, labeling and placarding, stowage, documentation and the prevention of marine pollution.

• The recommendations of the International Atomic Energy Agency (IAEA) are approved at the international level and apply to the transportation of radioactive materials in Japan and in France.

The rules are implemented by national authorities and rely first and foremost on the integrity of the cask, which ensures nuclear safety during shipment. Casks meeting IAEA specifications for Type B packages are required for the shipment of MOX fuel.

Regulatory bodies in charge of implementing the regulations

In France, the nuclear safety authority ASN is responsible for enforcing regulations concerning the safety of the shipments. The French radiological protection and nuclear safety institute IRSN provides safety assessment expertise to ASN.

In Japan, the Ministry of Transport (MLIT) and the Ministry of Economy, Trade and Industry (METI) are responsible for implementing transport regulations.

In the United Kingdom, the Department for Transport (DfT) is responsible for regulations governing transport. The Maritime and Coastguard Agency (MCA), an executive agency of the DfT, implements the regulations concerning ships and cargoes. The DfT’s Radioactive Materials Transport Division implements regulations concerning the transport of radioactive materials by any mode of transport.

Display the detail

What are the emergency response arrangements? 

Pacific Heron PNTL

Pacific Heron PNTL

In the very unlikely event of difficulties encountered by a ship transporting highly radioactive material, teams of marine and nuclear experts are available to provide 24/7 emergency assistance as required by international regulations.

Immediate measures can be deployed to rescue the ship or salvage its cargo if required in the event of an accident.  Contractual arrangements are in place with the leading sea rescue companies, which are ready to provide assistance at any time along all our routes. All PNTL ships are equipped with satellite navigation and tracking and towing and recovery equipment.

Emergency response drills are a requirement of international radioactive materials transport regulations and form an essential part of the contingency planning system. Several emergency training exercises are held each year: they test the communication systems, the effectiveness of the rescue teams and the ship’s crews, as well as the performance of the emergency equipment.

Display the detail

What is your communications policy for these shipments?

With our first shipment to Japan, we adopted a communications policy which reflects both our spirit of transparency and the need for confidentiality. Under the supervision of our respective countries, we developed a process involving press releases to provide information to the public on our shipments.

At the same time, we developed a Global Acceptance program to provide information to the authorities of countries with shores near our routes in order to inform international stakeholders of all aspects related to the safety and security of our shipments.

More than 20 years ago, we entered into proactive dialogue to answer the questions and concerns of countries located along our routes. We communicate directly with these nations, explaining our mission, the regulatory framework and the safety measures surrounding our transportation operations.

We continue our dialogue in all possible areas:

  • Building relationships of trust with coastal nations
  • Informing and providing continuous reassurance on the reliability of our transportation operations
  • Organizing visits with the support of our partners in the diplomatic sphere
  • Inviting political figures and local officials to visit our facilities in Europe to witness our professionalism and our constant concern for safety and security.