The purpose of the Mayak Production Association facility was to produce plutonium for nuclear weapons . In its earlier years of operation , exposures to radiation were significantly higher than at other similar facilities . Mayak was one of the largest nuclear facilities in the Russian Federation , and was formerly known as Chelyabinsk-40 and later as Chelyabinsk-65 . It was the site of the Kyshtym disaster ( 1957 ) when a storage tank explosion released 50-100 tons of high-level radioactive waste , contaminating a 290 square mile area in the eastern Ural mountains , causing radiation sickness and death . The event was rated 6 " serious accident " on the 7-level INES nuclear incident/accident scale . The incident received little attention , as it was kept secret for 30 years . Many laborers who worked at the plant during the 1950s and 1960s died from exposures to radiation . The accident was first reported in 1976by Zhores Medvedev in the journal New Scientist , it was in 1992 that the Russian government officially acknowledged the accident
Kyshtym disaster
Kyshtym disaster
Nuclear labor issues