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Electrochemical Plant (EKhZ) Production Association

  • Location
    Zelenogorsk, Krasnoyarsk Krai
  • Type
  • Facility Status

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Started up in 1962 in Krasnoyarsk-45 (now known as Zelenogorsk), the gaseous diffusion equipment (and, later, centrifuges) at the Electrochemical Plant (EKhZ) produced Highly Enriched Uranium (HEU) for the Soviet nuclear weapons program. Since becoming fully operational in 1970, and through the end of the Cold War, the facility’s enrichment capacity ranged from 1 million SWU/yr to 6-7 million SWU/yr. 1

The EKhZ is fully converted to civilian use and no longer produces HEU. Today, its primary activities include processing, transportation, and storage of Low-Enriched Uranium (LEU) fuel, the production of stable isotopes and radioisotopes, and the processing and storage of depleted uranium hexafluoride. 2 The plant’s enrichment capacity as of 2011 is 8.7 million SWU/yr, which Rosatom plans to expand to 12 million SWU/yr by 2020. 3 A new deconversion (defluorination) plant, commissioned at the site in 2009, processes depleted uranium so that it can be stored long-term as uranium oxide. 4 Through its participation in the U.S.-Russia HEU-LEU program, the facility also regularly handles HEU conversion (to UF6) and downblending. 5 It is estimated that approximately half of the EKhZ’s enrichment capacity has been allocated to re-enriching tails (depleted uranium) to provide 1.5% LEU for HEU downblending. 6

The Electrochemical Plant has received funding and assistance from the U.S. Government through the Department of Energy’s Materials Protection, Control and Accounting (MPC&A) Program beginning in 1996. 7


Diffusion: A technique for uranium enrichment in which the lighter Uranium 235 isotopes in UF6 gas move through a porous barrier more rapidly than the heavier Uranium 238 isotopes.
Centrifuge: A machine used to enrich uranium by rapidly spinning a cylinder (known as a rotor and containing uranium hexafluoride gas) inside another cylinder (called the casing).
Highly enriched uranium (HEU)
Highly enriched uranium (HEU): Refers to uranium with a concentration of more than 20% of the isotope U-235. Achieved via the process of enrichment. See entry for enriched uranium.
Enriched uranium
Enriched uranium: Uranium with an increased concentration of the isotope U-235, relative to natural uranium. Natural uranium contains 0.7 percent U-235, whereas nuclear weapons typically require uranium enriched to very high levels (see the definitions for “highly enriched uranium” and “weapons-grade”). Nuclear power plant fuel typically uses uranium enriched to 3 to 5 percent U-235, material that is not sufficiently enriched to be used for nuclear weapons.
Low enriched uranium (LEU)
Low enriched uranium (LEU): Refers to uranium with a concentration of the isotope U-235 that is higher than that found in natural uranium but lower than 20% LEU (usually 3 to 5%). LEU is used as fuel for many nuclear reactor designs.
Isotope: Any two or more forms of an element having identical or very closely related chemical properties and the same atomic number (the same number of protons in their nuclei), but different atomic weights or mass numbers (a different number of neutrons in their nuclei). Uranium-238 and uranium-235 are isotopes of uranium.
Radioisotope: An unstable isotope of an element that decays or disintegrates spontaneously, emitting energy (radiation). Approximately 5,000 natural and artificial radioisotopes have been identified. Some radioisotopes, such as Molybdenum-99, are used for medical applications, such as diagnostics. These isotopes are created by the irradiation of targets in research reactors.
Uranium is a metal with the atomic number 92. See entries for enriched uranium, low enriched uranium, and highly enriched uranium.
Downblending: Refers to the process of blending down HEU to LEU. This is done by mixing HEU and the blendstock (of natural, depleted, or slightly enriched uranium) in either liquid or gas form. See highly enriched uranium and low enriched uranium.
Material protection, control, and accountability (MPC&A)
MPC&A: An integrated system of physical protection, material accounting, and material control measures designed to deter, prevent, detect, and respond to unauthorized possession, use, or sabotage of nuclear materials. The U.S. Department of Energy's MPC&A program was implemented in cooperation with the Russian Atomic Energy Ministry and other agencies to install and upgrade physical protection systems at the nuclear energy and weapons production facilities in the successor states of the former Soviet Union. See entry for Cooperative Threat Reduction.


  1. Pavel Podvig, “History of Highly Enriched Uranium Production in Russia,” Science & Global Security, 19/2011, pp. 59-60.
  2. “Activities,” JSC “PA Electrochemical Plant,” www.ecp.ru.
  3. “Russia’s Nuclear Fuel Cycle,” World Nuclear Association, April 2014, www.world-nuclear.org.
  4. “Russia’s Nuclear Fuel Cycle,” World Nuclear Association, April 2014, www.world-nuclear.org.
  5. Pavel Podvig, “Consolidating Fissile Materials in Russia’s Nuclear Complex,” International Panel on Fissile Materials, May 2009, p. 25, www.fissilematerials.org.
  6. “Russia’s Nuclear Fuel Cycle,” World Nuclear Association, April 2014, www.world-nuclear.org.
  7. Jon Brook Wolfsthal et al., “Nuclear Facilities and Fissile Materials in the Former Soviet Union,” Nuclear Status Report, The Monterey Institute of International Studies and the Carnegie Endowment for International Peace, June 2001.


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