The results of research on the application of the method of measurement of gross alpha-, beta-activity in water using the liquid scintillation counter (LSC) Quantulus 1220 are presented. Basic procedures of preparation and spectrometric measurement of aqueous samples were studied and performed. The detection efficiency of alpha-, beta-particles depending on quenching and the optimum alpha-, beta-radiation separation parameter for the method used were determined. Testing and validation of the technique was carried out on model solutions with different concentrations and composition of alpha- and beta-emitters, as well as by participating in interlaboratory comparisons. The results demonstrated that the use of LSS allows for a sufficiently fast and accurate estimation of the gross alpha- and beta-activity in water below the regulated limits without the use of labor-intensive sample preparation.

“Atomic Lake” is one of the objects visited by tourists at Semipalatinsk test site. In this regard, the calculation of the radiation dose received by a person on “Atomic Lake” in conditions of high radiation is relevant. Behavioral scenarios typical when visiting the territory of “Atomic Lake” are highlighted: “Tourist”, “Staff”, “Farmer”.In the method used, the effective dose is represented as the sum of partial doses from external gamma radiation from the soil, inhalation intake of radionuclides, oral intake of radionuclides with food. The calculations used data obtained by the branch of RSE National Research Center of the Republic of Kazakhstan “Institute of Radiation Safety and Ecology”.   In behavioral scenarios, the annual effective dose is represented as the sum of partial doses from external gamma radiation from the soil, inhalation intake of radionuclides, oral intake of radionuclides from food.The results of the calculation of radiation doses showed that permanent residence of the population in this territory is excluded, since it leads to exceeding the annual effective radiation dose of the population established by the hygienic standard (GN SETORB). No excess of the annual effective dose is expected when Group A personnel and tourists visit the “Atomic Lake”, and the main source of exposure is external radiation from radionuclide 137Cs. At the same time, when living in the study area, the annual effective dose with oral intake of radionuclides with water leads to an excess of the established annual effective radiation dose of the population.