The concentrations of artificial and natural radionuclides in the bottom sediments of south-west Altai territory water bodies

The purpose of the research is to study and analyze the environmental condition of small streams and reservoirs in the southwestern part of the Altai Territory (Russia), which were previously exposed to radiation as a result of nuclear tests at the Semipalatinsk test site. Conducting the research, the authors obtained the results of studying the content of artificial and natural radionuclides in the bottom sediments of the water bodies under investigation. Sampling of bottom sediments and their analytical studies were carried out in 2020–2022. The sampling involved measurements of the dose rate of bottom sediment gamma radiation. Having dried and ground the samples, the authors measured the flux density of alpha and beta particles from the surface. Laboratory studies of the samples were carried out using highly sensitive analytical equipment including an ORTEC GEM25P4-70 gamma spectrometer, an Alpha Analyst A1200-32AM CANBERRA alpha spectrometer, and a TRI-CARB 3110TR PerkinElmer beta spectrometer. The activities of natural radionuclides (potassium-40, thorium-232, radium-226) and artificial radionuclides (americium-241, plutonium-239+240, cesium-137 and strontium-90) were identified in the bottom sediments. It was determined that the radiation parameters of bottom sediments of water bodies in the southwestern part of the Altai Territory do not exceed the standard level, and the remains of traces of nuclear tests that took place at the test site are not found in the studied water bodies today.