Abstract
Mining companies are potential sources of contamination of the environment by various pollutants, including technogenic radionuclides. Stepnogorsk Mining‐Chemical Combine (SMCC) functions over 50 years and is one of the largest complexes for production of uranium oxide and other rare metals. Radioactive waste of SMCC is accumulated in the tailing dumps with an area of 7.82 km2, located in 4 km to the North from Aksu village and Zavodskoy, where concentrated waste is with a mass of 44.17 million tons, and activity of 146.4 thousand Ku. The aim of this work was to evaluate the radiological situation of territories for sanitary protection zone of the tailings dumps (SZZH), including those in close vicinity to workers of the villages Aksu and Zavodskoy. As a result of the pedestrian gamma survey there were identified local, contaminated sites in the North‐East of SZZH SMCC with a length of 5 km. The most contaminated with radionuclides is the top layer of the soil 0‐5 cm. in the North‐East and South‐East direction from SZZH specific activity is 238U, 226Ra in the soil exceed the reference value in 16 times, 210Pb exceeds up to 7 times. In the samples of plants selected from the vicinity of villages in the South‐East and North‐East directions from SZZH it is noted high concentrations of natural radionuclides. In reservoirs of Sulukamys and Manybay thalwegs, located at a distance of 1.5 to 2 km in the Eastern and North‐Eastern part of the tailings dumps, the specific activity of technogenic radionuclides in the tens times higher than control values. On the territory of the village Aksu there were identified local, contaminated sites with a capacity of an equivalent dose of gamma radiation up to 0.86 mSv / h Possible additional radiation dose from external exposure for separate groups of the population of Aksu is from 0,86 mSv to 1,53 mSv per year.