Date: September 1950 - 28 October 1951
Location: Techa River, Russia, U.S.S.R.
Type of event: accidental and routine radiation releases
Processing of radioactive waste at the Mayak Production Association in 1949-1956 was accompanied by significant intentional and accidental releases of liquid radioactive waste into the Techa River. Routine releases began in January 1949 and mostly ceased by 28 October 1951 when releases were switched to Lake Karachay, though some contamination of the Techa River continued through 1956. The majority of releases into the river were from September 1950 to 28 October 1951, including large accidental releases during 8-12 October 1951. About 60% of strontium-90 and cesium-137 releases occurred in October 1951.
Response of Soviet authorities to address risk to local residents was slow. A ban on use of riverwater for drinking and household use was implemented around 1953. Use of riverwater likely continued until wells and water pipes provided alternate water sources by 1956. In 1953 a restricted zone was established regarding access to the river for people, cattle and water fowl. Barbed wire fences were placed between the river and settlements. Local residents were not told of the reason for these restriction nor of the risks, so violations of the restrictions were routine. A series of dams on the Techa River were built to limit water flow. Between 1954 and 1960 about 7000 residents were relocated.
Chronic radiation syndrome (CRS) was identified among residents near the Techa River by 1951-1953. At least 940 individuals were found to have CRS with a mean dose of 70 rad and maximum dose of 360-790 rad.
Consequences: 940+ injuries.
© 2022 by Wm. Robert Johnston.
Last modified 29 September 2022.
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