The Kyshtym disaster or Kyshtym incident was a radioactive contamination accident that occurred on 29 September 1957 at Mayak, a plutonium production site for nuclear weapons and nuclear fuel reprocessing plant located in the closed city of Chelyabinsk-40 (now Ozyorsk) in Chelyabinsk Oblast, Russian SFSR, Soviet Union.
MAYAK NUCLEAR FACILITY
• The Mayak Production Association is one of the biggest nuclear facilities in the Russian Federation, housing a reprocessing plant.
• The nuclear facility 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.
• The nearby lakes and water bodies provided a water supply for reactor cooling and also served as repositories for nuclear waste such as, Lake Karachay, Techa River.
• 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.
• The construction of the Mayak Plutonium plant started and completed between 1945–48 in Southern Urals, in great hurry and secrecy.
• It was the first reactor built to create Plutonium for the Soviet Union's atomic bomb project.
• More than 40,000 Gulag prisoners and POWs built the factory and the closed nuclear city of Ozersk, 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.
NEARBY WATER BODIES
o Lake Kyzyltash was the largest natural lake capable of providing cooling water to the reactors; it was rapidly contaminated via the open-cycle system.
o The closer Lake Karachay, too small to provide sufficient cooling water, was used as a dumping ground for large quantities of high level radioactive waste too "hot" to store in the facility's underground storage vats.
o The original plan was to use the lake to store highly radioactive material until it could be returned to the Mayak facility's underground concrete storage vats, but this proved impossible due to the lethal levels of radioactivity. The lake was used for this purpose until the Kyshtym Disaster in 1957.
• In the 1957, an underground tank of liquid nuclear waste at the Mayak facility exploded, spreading radioactive particles over the site and causing a radioactive plume of smoke that stretched for hundreds of miles.
• The disaster was a consequence of the failure to repair a malfunctioning cooling system in a buried tank where liquid reactor waste was stored. For more than a year the tank’s contents grew steadily hotter from radioactive decay, reaching a temperature of about 660 °F (350 °C) by September 29, 1957, when the tank exploded with a force equivalent to at least 70 tons of TNT.
• The nonnuclear explosion blew off the tank’s one-metre-thick concrete lid and sent a plume of radioactive fallout, including large quantities of long-lasting cesium-137 and strontium-90, into the air.
• The disaster was not widely known until 1976, when the exiled Soviet biologist Zhores A. Medvedev reported on the incident in the British journal New Scientist.
• Despite the evidence of a disaster, the Soviet Union denied its occurrence until 1989.
• The Mayak plant is associated with two other major nuclear accidents.
• The first occurred as a result of heavy rains causing Lake Karachay, a dried-up radioactively polluted lake (used as a dumping basin for Mayak's radioactive waste since 1951), to release radioactive material into surrounding waters.
• The second occurred in 1967 when wind spread dust from the bottom of Lake Karachay over parts of Ozersk; over 400,000 people were irradiated
EFFECTS OF THE DISASTER
• The radioactive material released through the air affecting an area of over 20,000 square kms. In other villages cancer rates increased significantly in the years following and genetic abnormalities and other illnesses became common.
• These affects can still be seen today. Though the plant stopped generating plutonium weapons in the late 1980s, the facilities still reprocess spent nuclear waste. While the safety features have been significantly upgraded since the Soviet era, current radiation levels are still disputed at the plant.
ENVIRONMENTAL IMPACT OF THE DISASTER
• In the early years of its operation, the Mayak plant directly discharged high-level nuclear waste into several small lakes near the plant, and into the Techa River, whose waters ultimately flow into the Ob River. Mayak continues to dump low-level radioactive waste directly into the Techa River today. Medium level waste is discharged into the Karachay Lake.
• According to the data of the Department of Natural Resources in the Ural Region, in the year 2000, more than 250 million m³ of water containing thousands of curies of tritium, strontium, and cesium-137 were discharged into the Techa River.
• The tritium concentration alone in the river near the village of Muslyumovo exceeds the permissible limit by 30 times.
OTHER WORST NUCLEAR DISASTERS AND ACCIDENTS
The Soviet Union had trumped over America in detonating the biggest nuclear warhead on October 30,1961. The AN602 hydrogen bomb recorded the most powerful man-made explosion ever to have taken place on Earth. It was detonated at Novaya Zemlya archipelago in the Arctic Ocean.
2.Hiroshima and Nagasaki
Two nuclear weapons have been exploded in the history of warfare, both by the United States during the World War II in 1945 resulted in the immediate deaths of around 1,20,000 people and more over time, because of the nuclear radiation.
• The worst nuclear accident in history, the 1986 Chernobyl disaster was a catastrophic nuclear accident that occurred on April 26, 1986 at the Chernobyl Nuclear Power Plant in Ukraine (then officially the Ukrainian SSR), which was under the direct jurisdiction of the central authorities of the Soviet Union.
• An explosion occurred due to a failed test and fire released large quantities of radioactive particles into the atmosphere, which spread over much of the western USSR and Europe.
• The battle to contain the contamination and avert a greater catastrophe ultimately involved over 5,00,000 workers and cost an estimated 18 billion rubles.
• As many as 31 people died during the accident itself and long-term effects such as cancers are still being investigated.
• The nuclear disaster at the Fukushima Nuclear Power Plant began on March 11, 2011 and resulted in a meltdown of three of the plant's six nuclear reactors when it was hit by a tsunami in the Tohoku region of Japan.
• The following day, on March 12, substantial amounts of radioactive material began to release, creating the largest nuclear incident since the Chernobyl disaster and the largest (after Chernobyl) to measure Level 7 on the International Nuclear Event Scale.
• Nuclear power authorities flooded the reactors with seawater, ensuring that the plant will never again be used.
5.Three Mile Island
• The Three Mile Island accident was a partial nuclear meltdown that occurred on March 28, 1979 in one of the two Three Mile Island nuclear reactors in Dauphin County, Pennsylvania, United States.
• A valve in the cooling system of the Three Mile Island nuclear reactor failed which was followed by a stuck-open pilot-operated relief valve in the primary system, which permitted large amounts of nuclear reactor coolant to escape. It was the worst accident in the US commercial nuclear power plant history.
6. Baneberry Test
• Of the many nuclear weapons tests conducted at Yucca Flat in Nevada, the 1970 Yucca Flat Baneberry Test, has been called "the most irradiated, nuclear-blasted spot on the face of the earth."
• Although the warhead was buried 900 feet below ground, the plug sealing the shaft from the surface failed and radioactive debris vented into the atmosphere. Eighty-six workers at the site were exposed to radiation.