Mayak

Built in total secrecy between 1945 and 1948, the Mayak plant was the first reactor used to create plutonium for the Soviet atomic bomb project. In accordance with Stalinist procedure and supervised by NKVD Chief Lavrentiy Beria, it was the utmost priority to produce enough weapons-grade material to match the U.S. nuclear superiority following the atomic bombings of Hiroshima and Nagasaki. Little to no consideration was paid to worker safety or responsible disposal of waste materials, and the reactors were all optimised for plutonium production, producing many tons of contaminated materials and utilising primitive open-cycle cooling systems which directly contaminated the thousands of gallons of cooling water the reactors used every day.

Lake Kyzyltash was the largest natural lake capable of providing cooling water to the reactors; it was rapidly contaminated via the open-cycle system. 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. 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 (see Pollution of Lake Karachay). The lake was used for this purpose until the Kyshtym Disaster in 1957, in which the underground vats exploded due to a faulty cooling system. This incident caused widespread contamination of the entire Mayak area (as well as a large swath of territory to the northeast). This led to greater caution among the administration, fearing international attention, and caused the dumping grounds to be spread out over a variety of areas (including several lakes and the Techa River, along which many villages lay).

Kyshtym disaster

Working conditions at Mayak resulted in severe health hazards and many accidents. The most notable accident occurred on 29 September 1957, when the failure of the cooling system for a tank storing tens of thousands of tons of dissolved nuclear waste resulted in a chemical (non-nuclear) explosion having an energy estimated at 75 tons of TNT (310 gigajoules). This released 740 PBq (20 MCi) of fission products, of which 74 PBq (2 MCi) drifted off the site, creating a contaminated region of 15,000–20,000 square kilometres (5,800–7,700 sq mi) called the East Urals Radioactive trace. Subsequently, an estimated 49 to 55 people died of radiation-induced cancer, 66 were diagnosed with chronic radiation syndrome, 10,000 people were evacuated from their homes, and 470,000 people were exposed to radiation.

The Soviet Union did not release news of the accident and denied it happened for nearly 30 years. Residents of Chelyabinsk district in the Southern Urals reported observing "polar-lights" in the sky near the plant, and American aerial spy photos had documented the destruction caused by the disaster by 1960. This nuclear accident, the Soviet Union's worst before the Chernobyl disaster, is categorised as a Level 6 "Serious Accident" on the 0–7 International Nuclear Events Scale.

When Zhores Medvedev exposed the disaster in a 1976 article in New Scientist, some exaggerated claims circulated in the absence of any verifiable information from the Soviet Union. People "grew hysterical with fear with the incidence of unknown 'mysterious' diseases breaking out. Victims were seen with skin 'sloughing off' their faces, hands and other exposed parts of their bodies." As Zhores wrote, "Hundreds of square miles were left barren and unusable for decades and maybe centuries. Hundreds of people died, thousands were injured and surrounding areas were evacuated." Professor Leo Tumerman, former head of the Biophysics Laboratory at the Institute of Molecular Biology in Moscow, disclosed what he knew of the accident around the same time. Russian documents gradually declassified from 1989 onward show the true events were less severe than rumoured.

According to Gyorgy, who invoked the Freedom of Information Act to open up the relevant Central Intelligence Agency (CIA) files, the CIA knew of the 1957 Mayak accident, but kept it secret to prevent adverse consequences for the fledgling US nuclear industry. "Ralph Nader surmised that the information had not been released because of the reluctance of the CIA to highlight a nuclear accident in the USSR, that could cause concern among people living near nuclear facilities in the USA." Only in 1992, shortly after the fall of the USSR, did the Russians officially acknowledge the accident.

1968 criticality incident

In December 1968, the facility was experimenting with plutonium purification techniques. Two operators were using an "unfavourable geometry vessel in an improvised and unapproved operation as a temporary vessel for storing plutonium organic solution". "Unfavourable geometry" means that the vessel was too compact, reducing the amount of plutonium needed to achieve a critical mass to less than the amount present. After most of the solution had been poured out, there was a flash of light and heat. After the complex had been evacuated, the shift supervisor and radiation control supervisor re-entered the building. The shift supervisor then entered the room of the incident, caused another, larger nuclear reaction and irradiated himself with a deadly dose of radiation.

2017 radiation release

Abnormally high levels of radiation were reported in the area of the facility in November 2017. Simultaneously, traces of radioactive manmade isotope Ruthenium-106 spread across Europe in September and October. Such a release had not been seen on a continental scale since the Chernobyl accident. In January 2018, the French Institute of Radioprotection and Nuclear Security (IRSN) reported that the source of the contamination is located in the Volga – Southern Ural region between 25 and 28 September for a duration of less than 24 hours. The report excludes the possibility of an accidental release from a nuclear reactor, stating that it seems related with irradiated fuels processing or the production of sources from fission products solution. It may point to Mayak's aborted attempt to manufacture a capsule of highly radioactive component cerium-144, for the SOX project in Italy. Both the Russian government and Rosatom denied at the time that another accidental leak took place at Mayak. The release of a cloud of ruthenium-106 is similar to the B205 reprocessing accident in Britain in 1973.

The nuclear complex 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. 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.

List of accidents

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 Ozyorsk; over 400,000 people were irradiated..

Major accidents at Mayak, 1953–1998

Source:

15 March 1953 – Criticality accident. Contamination of plant personnel occurred.

13 October 1955 – Rupture of process equipment and the destruction of a process building.

21 April 1957 – Criticality accident. One operator died from receiving over 3000 rad. Five others received doses of 300 to 1,000 rem and temporarily became sick with radiation poisoning.

29 September 1957 – Kyshtym disaster.