HEU to LEU: Step by Step | usec.com

HEU to LEU: Step by Step

See how the Megatons to Megawatts program recycles nuclear warheads into fuel for nuclear power plants.


Warhead dismantlement

The conversion of highly enriched uranium (HEU) from Russian nuclear weapons into low enriched uranium (LEU) for use in fabricating fuel for commercial nuclear power reactors takes place at several nuclear installations in Russia and begins with the removal of the warheads and their HEU metal components from strategic and tactical nuclear missiles.


Downblending of HEU to LEU


At the Siberian Chemical Enterprise (SChE) (formerly Tomsk-7) in Seversk and the Mayak Production Association (MPA) near Ozersk, the HEU warhead components are machined into metal shavings. The shavings are then heated and converted to an HEU oxide and any contaminants are chemically removed.


At SChE and the Electrochemical Plant (ECP) near Krasnoyarsk, the HEU oxide is converted to highly enriched uranium hexafluoride (UF6), a compound that becomes a gas when heated.


At SChE, ECP and the Urals Electrochemical Integrated Plant (UEIP) near Ekaterinburg, the highly enriched UF6 is introduced into a gaseous process stream. There, it is mixed with other material and is diluted to less than 5 percent concentration of the fissionable uranium-235 isotope, a level too low to be of any military value but ideal for producing electric power.

Transfer to Cylinders

At the three dilution facilities, the now low enriched uranium (LEU) is checked to ensure the product meets commercial specifications and is then transferred to 2.5-ton steel cylinders.

Shipment to St. Petersburg

Cylinders loaded for shipment

The LEU is enclosed in shipping containers and sent to a collection point in St. Petersburg. USEC takes possession of the containers in St. Petersburg and they are delivered to USEC’s facilities in the United States.

Arrival at USEC

USEC enrichment plant

At USEC’s facilities (originally the Portsmouth plant but now the Paducah plant), the LEU is tested again to ensure that it meets appropriate commercial and customer specifications. If necessary, the enrichment level of the uranium can be further adjusted to meet utility customers’ needs. 

Shipment to Fabricators

Fuel fabricator

USEC ships the warhead-derived LEU to fabricators (Global Nuclear Fuels, Framatome or Westinghouse), who convert it into uranium oxide pellets and fabricate them into fuel assemblies. The assemblies are then delivered to USEC's utility customers as a source of fuel for their nuclear reactors.

HEU Transparency Program

To provide confidence that the LEU from Russia is actually derived from warhead material, the U.S. Department of Energy and the National Nuclear Security Administration administer the HEU Transparency Program. Through this program, the NNSA monitors several steps in the process described above to provide confidence that the nonproliferation objectives are met.

Megatons to Megawatts

19,008Warheads Eliminated

As of May 2013 


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