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Lake Karachay

Lake Karachay (Russian: Карача́й), sometimes spelled Karachai is a small lake in the southern Ural mountains in eastern Russia. Starting in 1951[1] the Soviet Union used Karachay as a dumping site for radioactive waste from Mayak, the nearby nuclear waste storage and reprocessing facility, located near the town of Ozyorsk (then called Chelyabinsk-40).

According to a report by the Washington, D.C.-based Worldwatch Institute on nuclear waste, Karachay is the "most polluted spot" on Earth.[2] The lake accumulated some 4.44 exabecquerels (EBq) of radioactivity,[3] including 3.6 EBq of Caesium-137 and 0.74 EBq of Strontium-90.[1] For comparison, the Chernobyl disaster released from 5 to 12 EBq of radioactivity, however this radiation is not concentrated in one location.

The radiation level in the region near where radioactive effluent is discharged into the lake was 600 röntgens per hour in 1990, according to the Washington, D.C.-based Natural Resources Defence Council, [4][5] more than sufficient to give a lethal dose to a human within an hour.

"If Lake Karachay's radioactive load leaks into the Arctic Ocean, one of the planet's last great wildernesses, it could travel halfway across the globe."[6]


Starting in the 1960s, the lake began to dry out; its area dropped from 0.5 km2 in 1951[1] to 0.15 km² by the end of 1993.[7] In 1968, following a drought in the region, the wind carried radioactive dust away from the dried area of the lake, irradiating half a million people with 185 petabecquerels of radiation.[3]

Between 1978 and 1986 the lake was filled with almost 10,000 hollow concrete blocks to prevent sediments from shifting. The lake, which is now entirely covered by concrete, is referred to in the concept album One Hour by the Concrete Lake, by Pain of Salvation.


  1. ^ a b c
  2. ^ Lenssen, "Nuclear Waste: The Problem that Won't Go Away", Worldwatch Institute, Washington, D.C., 1991: 15.
  3. ^ a b
  4. ^
  5. ^
  6. ^ Sandia National Lab - Advanced Simulation and Computing Contamination Sites
  7. ^

Coordinates: 55°39′42″N, 60°51′16″E

This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Lake_Karachay". A list of authors is available in Wikipedia.
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