The Angarsk Electrolyzing and Chemical Combine (AEKhK) was established in the late 1950s to produce enriched uranium for the Soviet nuclear program. The gaseous diffusion plant in Angarsk attained its full capacity in 1964 and, at the time, was believed to be the most efficient of the existing Soviet enrichment facilities.
The enrichment plant in Angarsk has never produced HEU. Instead, its partially enriched uranium product was probably sent to other Soviet enrichment facilities to produce HEU. At present, the Combine accounts for 8 percent of Russia’s enrichment capacity.
In addition, the complex operates one of Russia’s two large conversion facilities producing UF6, the feed material for enrichment facilities. Uranium hexafluoride production technology began to be developed in the USSR in 1947. The first, relatively ineffective, fluorination processes involved uranium oxide dissolution in sulfuric acid, electrolytic uranium sulfate reduction, and hydrofluorination. In 1965, the technology of fluorination in a vertical plasma reactor was created and is still in use today. Conversional plants in Russia are located at the same sites as uranium concentration mills: in Sverdlovsk-44 / Novouralsk (close to Yekaterinburg) and Angarsk. The productivity of conversion enterprises matches that of concentration mills, and the uranium enrichment on average is 2.18%. Uranium hexafluoride is then transported to concentration mills located at Tomsk, Krasnoyarsk, Angarsk, and Sverdlovsk-44.