[Ecological and radio-ecological effects from long-term use of the lake Kyzyl-Tash as a cooling reservoir by the nuclear fuel cycle facility].
This review introduces long-term study findings on ecological and radiation induced regime of the water reservoir - lake Kyzyl-Tash (R-2) - used as a heat sink of nuclear-power reactors in the Southern Urals from 1948 through 2008. It was exhibited that water reservoir exploitation by the nuclear fuel cycle facility "Mayak" PA resulted in hydrological, thermal, hydrochemical and radiological ecosystem regimes changes. The central radioactive substances depot in the water reservoir was determined to be the upper 20-30 cm bed silt layers, contamination density of which in 1980-1990s amounted on average approximately 0.2 PBq/km2 (about 5 kKu/km2). Some regularities of radionuclide distribution in bed sediments and biota were ascertained. Dose estimates from ionizing exposure to fish inhabited the water reservoir were experimentally made. Dose contribution was mainly due to incorporated beta-emitters amounted up to 2-3 Gy/y in 1980s. The leading role in the reservoir life belonged to phytoplankton with its algal nuisance periodicity constituting 5-6 years for blue-green and diatomic algae, and 2-3 years for green algae. During periods of the highest development pressure phytoplankton productive capacity in the reservoir was by an order of magnitude greater compared to control water reservoirs of the region. Combined long-term impact of radiological and chemical factors did not cause irreversible changes either in fish populations or ecological system in general. It can be proved by the fact that during 1970-1980s the water reservoir R-2 was inhabited by such cleanness indicators as crawfish (Astacus leptodactylus) and shellfish (Anodonta cygnea L.). On reducing of thermal and chemical pressure in the end of 1980s some processes observed gave evidence of ecosystem restoration in the lake Kyzyl-Tash. At the present moment the situation of the water reservoir exploiting as a heat sink is stabilized with preserved self-cleaning capacity.
Smagin
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D000818:Animals; D003400:Astacoidea / Q000254:growth & development / Q000528:radiation effects; D055669:Ecological and Environmental Phenomena; D017753:Ecosystem; D005399:Fishes / Q000254:growth & development; D005618:Fresh Water / Q000032:analysis* / Q000737:chemistry; D009688:Nuclear Reactors; D010839:Phytoplankton / Q000528:radiation effects; D011834:Radiation Monitoring / Q000379:methods*; D011850:Radioactive Waste; D012800:Siberia; D013997:Time Factors; D014875:Water Pollutants, Radioactive / Q000032:analysis*
D011850:Radioactive Waste; D014875:Water Pollutants, Radioactive