Radionuclide activity in soil samples at a site from Atomic Lake to the neighbor winter camps of Sarapan and Zhanan at the boundary of the southeast part of Semipalatinsk test site

In this investigation we studied the content of some extremely dangerous radionuclides ( ¹³⁷ Cs, ⁹⁰ Sr, ²⁴¹ Am, ^239+240 Pu) in soil samples taken around "Atomic lake" moving from the explosion crater by 4 terrains. Selected sampling terrains pass through the wintering grounds of Sarapan and Zhanan located at the south-east part of the former Semipalatinsk test site (STS). The research results have shown that soil samples near "Atomic lake" have a wide range of radionuclide activity values: ¹³⁷ Cs from 6.8 to 4500 Bq/kg, ⁹⁰ Sr from < 8 to 4300 Bq/kg, ²⁴¹ Am from 1 to 350 Bq/kg, ^239+240 Pu from 7 to 1800 Bq/kg. The highest radioactivity levels are found in soil samples near "Atomic lake". The content of ²⁴¹ Am is within the admissible limit values, whereas the content of ¹³⁷ Cs and ^239+240 Pu exceeds the regulated values at some sampling places. The coefficient of variation of radionuclides content in studied soils has high values: ¹³⁷ Cs (240%), ⁹⁰ Sr (193%), ²⁴¹ Am (225%), and ^{239 + 240} Pu (225%). This fact shows a high degree of the results scatter, which is most likely associated with a high activity of soils near "Atomic Lake".