AREVA logo

Production of MOX fuel

Cleaning rods prior to pellet insertion in the MOX plant

MELOX facility, located on the Marcoule nuclear site in Gard region of France, produces MOX fuel assemblies intended to feed light water reactors. Created from a mixture of uranium oxides and plutonium, MOX fuel enables the recycling of plutonium issuing from used fuel recovered during treatment operations executed at the AREVA La Hague recycling site.

Leading from the front

MELOX is the world leader in the production of MOX fuel, with more than 1,700 MTHM (metric tons of heavy metal) and nearly 3,300 fuel assemblies produced by the end of 2010.

To keep in step with market developments, in 2006 AREVA MELOX submitted an authorization request to increase its annual production from 145 MTHM to 195 MTHM.

Following a public consultation held across 7 municipalities in the Gard region (and 4 municipalities in the Vaucluse region), MELOX was granted authorization in April 2007 to progressively increase its production to 195 MTHM per year.

Following the cessation of MOX production at the AREVA Cadarache plant in July 2003, AREVA has consolidated MOX production at its MELOX plant.

This exercise has involved AREVA’s delivery of nearly 6,600 MOX fuel assemblies to customers across MELOX and the two old factories of its recycling platform, AREVA Cadarache and Belgonucléaire now ceased their activity.

The fabrication of MOX fuel

fuel fabrication scheme

click  to enlarge

The fabrication of MOX (mixed oxides) fuel is similar to that of uranium oxide fuels. It is performed in 5 phases:

  • Mixing the powders: first, a primary mix is created, using plutonium oxide and depleted uranium oxide, and "chamotte" powders obtained from discarded pellets. Depleted uranium is added to this primary mix to obtain the exact concentration required by customers. The resulting material is called the secondary mix. Concentration of plutonium constitute of a fuel assembly (ranging from 3-12% concentration). Fuel concentrations are based on customer specifications.
  • Sintering: the secondary mixture is compacted in the form of pellets. These are fired in an oven at a high temperature for conversion into ceramic materials
  • Grinding: the pellets are ground to obtain the required pellet diameter, to the nearest micron. Pellets which do not meet the required specifications are returned for recycling into chamotte. 
  • Graining: the pellets are then inserted into zirconium alloy tubes known as “rods.” Each rod is about 4 meters long and is made up of around 320 pellets, depending on customer requirements. The rods are then carefully cleaned, and subsequently inspected.
  • Assembly: this final stage involves inserting the rods into a metal structure to form a “fuel assembly.” This assembly is the finished product for customer delivery. These assemblies are subject to manufacturing inspections to verify their future performance in the reactor.

Almost 130 quality control parameters are monitored throughout the manufacturing process.

In 2010, 128 metric tons of heavy metal and 285 MOX assemblies were produced. A recycled fuel assembly provides sufficient energy to power a city of 100,000 inhabitants for one year.

MOX fuel customers

41 reactors worldwide have been loaded with MOX fuel assemblies since the beginning of the 1970s: 36 of these are in Europe (21 in France, 10 in Germany, 3 in Switzerland and 2 in Belgium), 1 is in the United States and 4 are in Japan or 10% of the world of light water reactors.

Campaigns manufacturing 2010.

  • France: the year 2010 saw the continuation of production and delivery parity MOX for EDF. The fabrications EDF represent nearly two-thirds of the total capacity of MELOX.
  • Japan: recycling program for spent fuel in Japan has continued since the revival of the Japanese nuclear program in 2006. In 2010, two production campaigns were conducted for Kansai and Chubu electricians. Meanwhile, fuel produced in 2009 for electricians Kansai and Kyushu were delivered to Japan in July 2010.
    Recall that the Genkai Unit 3 of the electrician had made Kyushu December 2, 2009 the first commercial production of electricity from MOX fuel in Japan.
  • Germany: Both campaigns have been delivered to the power companies E. ON (Isar) and EnBW (Neckarwestheim) in 2010.

Know-how and technology from AREVA are internationally recognized.

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 technology MELOX 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. The plant called MFFF (MOX Fuel Fabrication Facility) is located on the Savannah River Site in South Carolina. Its construction started on 1 August 2007. Its commissioning is planned for 2016.

Japanese manufacturers in charge of the J-MOX project also uses technology to implement AREVA MELOX to produce MOX fuel in their country. The plant will be built on the same site as the treatment plant at Rokkasho-Mura.

Finally, AREVA is involved in the consortium, Nuclear Management Partners Limited, that won the 2008 tender for the operation of the Sellafield site in the UK.

Fifteen employees based in MELOX are currently involved in international projects

EUROFAB program: “MOX for peace”–recycling military fuel

During the 1990s, the United States and the Russian Federation committed to reducing their nuclear arsenal. Both states decided to dispose of 34 metric tons each of plutonium produced for defense purposes.

In 2003, the AREVA group was chosen by the United States to produce 4 MOX fuel assemblies from American plutonium of military origin.

The production of these assemblies was carried out on 2 sites.

  • Fabrication of pellets and rods took place at the AREVA NC Cadarache facility in the fall of 2004.
  • Fuel assembly operations took place at the MELOX plant in early 2005.

The 4 assemblies produced were loaded in June 2005 into the Catawba nuclear power plant, owned by the American electrical utility company Duke Power. They have enabled the production of power sufficient to meet the electricity demands equivalent to those of a city of nearly 10,000 inhabitants a year. The American program demonstrates that civil nuclear applications, and the use of MOX in particular, can contribute to the non-proliferation of nuclear weapons.