The first Soviet reactor built to produce plutonium for military purposes, called Annushka (A for short), began operating at Mayak in June 1948. The reactor was a single-purpose, water-cooled, graphite-moderated, single-pass reactor.[1,10] Four additional graphite-moderated plutonium production reactors were built at Mayak between 1950 and 1952.[10] In addition to the graphite-moderated reactors, one heavy water-moderated reactor was also built during this period. All five of the plant's uranium-graphite plutonium production reactors (A, IR, AV-1, AV-2, and AV-3) have been permanently shut down.[2,3,4] These five reactors reportedly produced a total of 58.3t of plutonium.[5] Two tritium-producing reactors--Ruslan and Lyudmila--are still in operation.[4,6,7] The fuel for these reactors consists entirely of HEU.[8] 

 

Ruslan, which was rebuilt from the old heavy-water reactor and put in operation in 1979, is a pool-type light-water reactor (water-cooled, water moderated). Lyudmila, a heavy-water reactor, became operational in 1987. Both reactors continue production of tritium for nuclear weapons. They also produce various isotopes, including plutonium-238, cobalt-60, irridium-192, carbon-14, cesium, and others. According to the director of Plant 23, which houses the two reactors, 60% of Luydmila's output is for civilian programs. Ruslan is less suitable for civilian production, so barely 15% of its capacity is used for civilian purposes. The plant director noted that it is feasible and desirable to modify Ruslan in order to increase its civilian production capacity.[9,10,11] According to an article in Nauka i zhizn, Mayak reactors produce 20% of world output of isotopes.[10] 

Sources:

[1] Alexander M. Dmitriev, "Converting Russian Plutonium-Production Reactors to Civilian Use," Science & Global Security, Vol. 5, 1994, pp. 37-46.

[2] Nucleonics Week, 23 May 1992, p. 14.

[3] "The Radiochemical Facility "Mayak" At Chelyabinsk," Surviving Together, Winter 1994, p. 29.

[4] Thomas B. Cochran, Robert S. Norris, and Oleg A. Bukhkarin, Making the Russian Bomb: From Stalin to Yeltsin, (Boulder: Westview Press, 1995), p.75.

[5] Nils Bohmer and Thomas Nilsen, "Reprocessing Plants in Siberia: Ozersk," Bellona Web Site, http://www.ngo.grida.no/ngo/bellona/ehome/russia/sibir/sibir1.htm#O2, 12 April 1996.

[6] Aleksandr Yemelyanenkov and Vladimir Popov, eds., Atom Bez Grifa "Sekretno": Tochki Zreniya, (Berlin: H&P Druck, 1992), pp. 9-10.

[7] Discussions with Russian nuclear official, December 1995.

[8] Oleg Bukharin, "Integratsiya voyennogo i grazhdanskogo yadernykh toplivnykh tsiklov v Rossii," Yadernyy Kontrol, September 1995, pp. 10-13.

[9] Vladislav Larin, "Mayak Integrated Plant: What Is It?" Energiya: Ekonomika, Tekhnika, Ekologiya, No. 3, March 1996, pp. 24-31; in "Documents Reveal Details of Urals Nuclear Disaster," FBIS-UST-97-002.
[10] Vladimir Gubarev, "'Ruslan' i 'Lyudmila,' reaktory dlya termoyadernogo oruzhiya i izotopov," Nauka i zhizn, No. 6, 1997, pp. 78-83.
[11] "4 aprelya 2000 goda ispolnilos 50 let reaktornomu zavodu PO 'Mayak' - zavodu 23," PO Mayak Web Site, http://www.ozersk.ru/mayak/23zavod.shtml, April 2000. {Updated 10/23/2001 ES}

Mayak Production Association (PO Mayak) Summary
PO Mayak Developments
Mayak Chemical Combine
Reactors
Reprocessing Facilities
 Spent Fuel Developments
MOX Fuel Production Facilities
Fissile Material Facilities
Radioactive Waste
 Chelyabinsk-60 Research Facility