# Mayak

The Mayak Production Association (Russian: Производственное объединение «Маяк», Proizvodstvennoye ob′yedineniye "Mayak", from Маяк 'lighthouse') is one of the largest nuclear facilities in the Russian Federation, housing a reprocessing plant. The closest settlements are Ozyorsk to the northwest and Novogornyi to the south.
Lavrentiy Beria led the Soviet atomic bomb project. He directed the construction of the Mayak Plutonium plant in the Southern Urals between 1945 and 1948, in a great hurry and secrecy as part of the Soviet Union's atomic bomb project. Over 40,000 Gulag prisoners and POWs built the factory and the closed nuclear city of Ozyorsk, called at the time by its classified postal code "Forty". Five (now closed) nuclear reactors were built to produce plutonium which was refined and machined for weapons. Later the plant came to specialise in reprocessing spent nuclear fuel from nuclear reactors and plutonium from decommissioned weapons.
Once production began, engineers quickly ran out of underground space to store high-level radioactive waste. Rather than cease production of plutonium until new underground waste storage tanks could be built, between 1949 and 1951, Soviet managers dumped 76 million cubic metres (2.7 billion cubic feet) of toxic chemicals, including 3.2 million curies of high-level radioactive waste into the Techa River, a slow-moving hydraulic system that bogs down in swamps and lakes.
As many as 40 villages, with a combined population of about 28,000, lined the river at the time. For 24 of them, the Techa was a major source of water; 23 of them were eventually evacuated. In the 45 years afterwards, about half a million people in the region have been irradiated in one or more of the incidents, exposing them to up to 20 times the radiation suffered by the Chernobyl disaster victims outside of the plant itself.
Investigators in 1951 found communities along the river highly contaminated. On discovery, soldiers immediately evacuated the first downriver village of Metlino, population 1,200, where radiation levels measured 3.5–5 rads/hr (35–50 mGy/hr or 10–14 μGy/s). At that rate, people would get the equivalent of a lifetime exposure to radiation in less than a week. During the following decade, ten additional communities were resettled from the river, but the largest community, Muslumovo, remained. Researchers investigated residents of Muslumovo annually in what has become a four-generation living experiment of people living among chronic, low doses of radioactivity. Blood samples showed its villagers took in caesium-137, ruthenium-106, strontium-90, and iodine-131, internally and externally. These isotopes had deposited in organs, flesh and bone marrow. Villagers complained of various illnesses and symptoms—chronic fatigue, sleep and fertility problems, weight loss, and increased hypertension. The frequency of congenital disabilities and complications at birth was three times greater than normal. In 1953, doctors examined 587 of 28,000 exposed people and found that 200 had clear cases of radiation poisoning.
In 1957 Mayak was the site of the Kyshtym disaster, which at the time was the worst nuclear accident in history. During this catastrophe, a poorly maintained storage tank exploded, releasing 20 million curies (740 PBq) in the form of 50–100 tons of high-level radioactive waste. The resulting radioactive cloud contaminated an expansive territory of more than 750 km$^2$ (290 sq mi) (a nine-mile radius) in the eastern Urals, causing sickness and death from radiation poisoning.
The Soviet government kept this accident secret for about 30 years. It is rated at 6 on the seven-level INES scale. It is third in severity, surpassed only by Chernobyl in Ukraine and Fukushima in Japan.
Mayak is still active as of 2020, and it serves as a reprocessing site for spent nuclear fuel. Today the plant makes tritium and radioisotopes, not plutonium. In recent years, proposals that the plant reprocess waste from foreign nuclear reactors have given rise to controversy.
An incompletely reported accident appears to have occurred in September 2017; see Airborne radioactivity increase in Europe in autumn 2017.

## Location

The nuclear complex is 150 km south of Ekaterinburg, between the towns of Kasli and Tatysh, and 100 km northwest of Chelyabinsk. The closest city, Ozyorsk, is the central administrative territorial district. As part of the Russian (formerly Soviet) nuclear weapons program, Mayak was formerly known as Chelyabinsk-40 and later as Chelyabinsk-65, referring to the postal codes of the site.

## Design and structure

Mayak's nuclear facility plant covers about 90 square kilometres (35 sq mi). The site borders Ozyorsk, in which a majority of the staff of Mayak live. Mayak itself was not shown on Soviet public maps. The location of the site together with the plant city was chosen to minimise the effects that harmful emissions could potentially have on populated areas. Mayak is surrounded by a ~250 square kilometres (97 sq mi) exclusion zone. Nearby is the site of the South Urals nuclear power plant.