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National Nuclear Security Administration – The MOX Project

In 2000, Russia and the United States signed the Plutonium Management Disposition Agreement (PMDA) requiring each country to permanently dispose of 34 metric tons of surplus weapons-grade plutonium. 

After evaluating disposal methods, a National Academy of Sciences (NAS) report in 1994 identified two options for plutonium disposition: Permanently downblend the surplus weapons-grade plutonium with uranium into mixed oxide (MOX) nuclear reactor fuel, or immobilize and store the plutonium through vitrification and deep geologic burial.

Noting that the immobilization option was not acceptable to Russia - they stated that the process was insufficient in rendering the plutonium unusable for a nuclear weapon, and the plutonium was a valuable energy source - the report recommended the MOX fuel option.

To fulfill this agreement, the National Nuclear Security Administration (NNSA) contracted with a consortium, now named CB&I AREVA MOX Services LLC, to design, build, and operate a Mixed Oxide Fuel Fabrication Facility (MFFF), also called the MOX Project. The decision was made to build a single facility on the Savannah River Site (SRS) in Aiken, South Carolina, based on a combined design of AREVA's La Hague used fuel reprocessing facility and its MELOX MOX fuel manufacturing facility, both located in France. The U.S. Nuclear Regulatory Commission (NRC) granted a license to construct the project, and has licensing and oversight authority during the facility's operation and decommissioning.

MOX Fuel Fabrication Facility (MFFF)

Begun in 2007, the Mixed Oxide Fuel Fabrication Facility (MFFF), or MOX Project, is located on the Savannah River Site near Aiken, South Carolina. The MOX Project has more than 4,000 suppliers across 39 U.S. states.

The design for the MOX facility is based on AREVA’s recycling technology that has been used successfully for almost two decades. AREVA’s MELOX and La Hague facilities in France currently supply MOX fuel to over 30 nuclear reactors world wide, and the expertise and know-how from these facilities will provide this basis for the MFFF technology and design.

Upon completion, the MOX Project will be a key component in the United States' nonproliferation agreement process. Similar to the French facilities' processes, the MOX Project will take surplus weapons-grade material consisting of 93 percent plutonium, remove the impurities, and downblend the plutonium 239 with uranium oxide 238 to achieve a 5 percent or less plutonium concentration to form mixed oxide (MOX) fuel pellets for commercial reactor fuel assemblies. These assemblies will then be sent to commercial nuclear power plants where they will be used in nuclear reactors to generate electricity.

When operational, the facility will be capable of permanently converting 34 metric tons of U.S. surplus weapons-grade plutonium into safe, stable, and secure nuclear reactor fuel to reliably power American businesses, industry, and homes. To put this energy impact into perspective, the MOX Project's output could generate enough power for 15 million homes for a year and indirectly create more than 4,000 American jobs.

Construction of the MOX Facility

The MFFF consists of two major sections, the Aqueous Polishing section and the MOX section. In the seven-layer aqueous polishing section, weapon-grade material is cleaned and purified, before it is sent to the MOX section. The MOX area is where the fabrication of the fuel takes place. This involves blending polished plutonium and depleted uranium to form the fuel pellets which are hardened, sized and loaded into fuel rods. The rods are then used to build fuel assemblies of the MOX fuel to be shipped to commercial utilities.

The Nuclear Regulatory Commission (NRC) will license and oversee the facility. AREVA’s design is being customized to ensure that the facility meets all U.S. federal safety and security requirements.  It will also be a hardened facility, similar to a nuclear reactor. Security will be equal to the security measures currently in place at the Savannah Rive Site. A Perimeter Intrusion Detection and Assessment System will encircle the facility for additional protection.

When operational, the facility will be capable of turning 3.5 metric tons of weapon-grade plutonium into MOX fuel assemblies annually. The facility will be licensed for 20 years, with operations expected to continue into the 2030s.

Numbers for construction of the 600,000 ft2 facility (including support facilities) include: over 170,000 yd3 of concrete, 35,000 tons of reinforcing steel, 23,000 instruments, 1000 tons of Heating Vents and Air conditioning 500,000 linear feet of conduit, 47,000 linear feet of cable tray, 3,000,000 linear feet of power and control cable, and 80 miles of piping.

MOX construction continues to progress with a strong nuclear safety and quality record.

What is MOX fuel?

Mixed Oxide (MOX) fuel is a mixture of approximately 95 percent uranium oxide and 5 percent plutonium oxide. The MOX Fuel Fabrication Facility will blend the 5 percent of plutonium oxide (PuO2) with the 95% of uranium oxide (UO2) powder to make a mixed oxide powder.

This powder is milled to ensure uniform distribution of the plutonium, and to adjust the particle size of the MOX powder. The MOX powder is made into small pellets about the size of a pencil eraser. These pellets are pressed into shape, baked at high temperatures, and ground down to approximately 1/3 inch in diameter and 4/10 inch in length, the required dimensions of reactor fuel rods.

The finished pellets are loaded into fuel rods through an open end. An end plug is then inserted into the open end of the fuel rod and the rod is welded shut. The fuel rods are inspected, decontaminated, and bundled together to form fuel assemblies. Each fuel assembly is then prepared for transportation to a commercial nuclear power plant, where it is used as fuel in a nuclear power reactor.

Simply put, the MOX Project takes weapons-grade plutonium and reduces it down to become usable nuclear fuel to power America.