SPECIFIC FEATURES OF THE FORMATION OF THE TECHA RIVER RADIOACTIVE CONTAMINATION
Author: Glagolenko Yu.G., Drozhko E.G., Mokrov Yu.G.
Reference: Gazette “ВОПРОСЫ РАДИАЦИОННОЙ БЕЗОПАСНОСТИ“ (Issues on radiation safety), 2007
ISSN: 1816-9643
DOI: 546.42 : 551.48
Keywords: Techa river, beta-emitting radionuclides, alpha-emitting radionuclides, long-lived 90sr and 137cs, Mayak production
Abstract: During 1949-1956 while implementing the State defense program by the Mayak Production Association routine (specified in the detail design) and accidental discharges of the liquid radioactive waste (LRW) into the open hydrographic system of the Techa river were performed. The discharged LRW consisted mainly of beta-emitting radionuclides of fission-fragment origin with half-life from several days to dozens of years and insignificant amounts (traces) of alpha-emitting nuclides (U, Pu, Am). By the middle of the 1960-s practically all the radionuclides contained in the discharged LRW had been subjected to the natural radioactive decay, and the river system radioactive contamination was determined only by the long-lived 90Sr and 137Cs and to a considerably lesser degree by the plutonium (238, 239, 240Pu) and 99Тс. The major part of the activity of the mentioned above radionuclides was deposited upon the swampy flood-plain area (Asanovsky swamps) in the upper Techa river. The following sources of the Techa river water radioactive contamination have been studied in this wok: – sorption-desorption of the activity from the Asanovsky swamps (90Sr); – bottom sediment stirring and activity transfer with suspensions (137Cs, Pu); – overland radioactive run-off from the catchment territory of the Techa river contaminated as a result of accidents occurred in 1957 and 1967 (90Sr, 137Cs); – filtration transfer of the activity from the Techa reservoir cascade (tritium, 90Sr). The data on activity margin of 90Sr, 137Cs, Pu and 99Тс deposited upon different river sections are provided. The analysis of the experimental and calculated data on volumetric activity and radioactive run-off of tritium, 90Sr, 137Cs, 99Tc and plutonium with the Techa river water depending on the water flow in the river is presented.