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Coat of arms of Kyshtym
'Kyshtym' () is a town in
Chelyabinsk Oblast,
Russia, located on the eastern slope of the South
Ural Mountains some 90 km northwest of
Chelyabinsk, near the town of
Ozyorsk. Population: 41,929 (
2002); 36,000 (
1970).
Nuclear disaster
Kyshtym is near the
Chelyabinsk-40 nuclear complex, also known as "
Mayak" ("beacon" in Russian), where on 29th September, 1957, a violent explosion involving dry nitrate and acetate salts in a waste tank containing highly radioactive waste, contaminated an area later called the "Kyshtym footprint". The explosion resulted from a failure of the cooling system of the tank.
[1]
There was a release of 40
PBq of
fission products. Cerium-144 and Zirconium-95 made up 91% of the release. There was 1 PBq of Sr-90, and 13 TBq of Cs-137. The contaminated zone, called 'East Urals Radioactive Trace' ('EURT'), measuring 300 x 50 km was contaminated by more than 4 kBq/m² of Sr-90. The global fallout of Sr-90 was about 2 kBq/m². An area measuring 17 km² was contaminated by about 100 MBq Sr-90/m².
There were 270 000 inhabitants of the area. Mass evacuation was carried out as the critical contamination resulted from Sr-90 with an effective half-life of 10-20 years. About 800 km² of land were taken out of use, and 82% of this area has now been taken into use again for forestry and farming.
The Kyshtym accident has been largely concealed by the Soviet government, until 1980, when the Soviet biologist
Zhores Medvedev revealed its existence.
References
1. "Kyshtym accident" ''TED Case Studies: An Online Journal'' American University