A year ago, at the Mayak industrial site, work was completed to liquidate the open water area of the V-9 industrial reservoir - Lake Karachay. Media representatives witnessed the placement of the last hollow concrete blocks on the bottom of the reservoir and how the surface was covered with rock.
The completion of the conservation of Karachay has become a historic event for the Mayak plant, the region and the nuclear industry, allowing us to talk about the solution of one of the most important problems that have been inherited from the Soviet atomic project. The federal target program "Ensuring nuclear and radiation safety for 2008 and for the period up to 2015" helped.
Dead Water Sentries
A serious monitoring system monitors the underground water circuit, the condition of the backfill elements, and this observation will be carried out by specialists of Mayak and specialized scientific organizations for several more decades. Karachay, which can serve as a classic example of a special radioactive waste disposal site, will exist for many hundreds of years. Special studies have proven that it is safer to leave such a repository where it is now, rather than to engage in the extraction and reburial of dangerous fractions to another place.
“A year has passed, the filled-up reservoir did not bring any surprises,” notes Dmitry Soloviev, acting head of the environmental service at Mayak PA. - We have installed 1090 signs on which marks are made whether there is ground movement or not. The processed data will become the basis for building a 3D model of the processes occurring under several layers of backfill. At each such point, the dose rate monitoring is additionally carried out, depending on the soil shrinkage and the water level in the closed part of the water area."
The efforts of specialists from Gidrospetsgeologii, Mayak, the USSR Academy of Sciences (and then the Russian Academy of Sciences), leading mathematicians and programmers of the Physics and Power Engineering Institute from Obninsk were initially focused on the study of groundwater migration. Together, a three-dimensional model was created, which made it possible to predict the dynamics of processes for centuries to come.
“All our efforts are now aimed at justifying the next stages of conservation of Karachay and its transfer to a new legal status - a“burial point”, - says Yuri Mokrov, advisor to the general director of PA Mayak for science and ecology. - This procedure will take several years. After that, both the reservoir and the adjacent territory, as required by law, will be transferred to the operation of the National Operator for Radioactive Waste Management. Mayak's specialists are involved in substantiating various aspects of the safety of the reservoir. This is a work that has no analogues in the world today. During the first ten months of monitoring after the closure of the Karachai water area, a decrease in the fallout of radionuclides to the surface was recorded, and the level of groundwater in the reservoir is at the standard levels and does not cause concern. This led to further improvement of the radiation situation in the area of the enterprise and nearby settlements."
The history of the nuclear swamp
What is Karachay? Reservoir V-9, formed in 1951 on the site of a former closed swamp, is a surface storage facility for intermediate level liquid radioactive waste. Its operation lasted 64 years. Wastes from nuclear weapons production amounting to several hundred million Curies were dumped in Karachay. Since the beginning of the operation of the V-9 reservoir, its level has been rising, the area of the water area has been constantly increasing. The well-known natural-man-made accident of 1967 (wind spreading of bottom sediments), fortunately, did not lead to serious radiation consequences for the population and the environment, but showed the potential danger of a repetition of this in the future under abnormal meteorological conditions. After this incident, the USSR government decided to liquidate Karachay.
During 1967–1971, previously bare areas and shallow waters were filled in, and the areas around the lake were reclaimed. Until the mid-70s, the liquidation of the consequences of the emergency continued, the coastal development was carried out, and experimental work on backfilling the water area began. By the mid-80s, this technology was finally debugged. It was decided to fill the reservoir with rocky soil using special structures - hollow concrete blocks, which allow localizing bottom sediments. At present, more than 200 thousand cubic meters of highly active technogenic silts and loams forming the bed of the reservoir are reliably isolated in Karachai.
However, the history of the V-9 reservoir does not end there. As already mentioned, it will be followed for decades.
Karachay, Karachay …
The Chelyabinsk Region is known for the most significant accumulation of radioactivity centers. In 1949, the country's first industrial plutonium production complex was launched here, and the Mayak production association was established. The tight deadlines for putting nuclear facilities into operation, with almost complete absence of radiation and technological control systems, led in 1949-1956 to the discharge of a huge amount of liquid radioactive waste into the Techa River.
In September 1957, an explosion occurred at Mayak, which resulted in the formation of a radioactive cloud that covered the territory of the Chelyabinsk, Sverdlovsk and Tyumen regions.
Since the beginning of the 50s, waste has also been dumped into the shallow swampy lake Karachay.
