Radiation-Hygienic Monitoring in Potentially Radon-Hazardous Territories [РАДИАЦИОННО-ГИГИЕНИЧЕСКИЙ МОНИТОРИНГ НА ПОТЕНЦИАЛЬНО РАДОНООПАСНЫХ ТЕРРИТОРИЯХ]

Modern radioecological studies to assess the effect of natural radiation on the human body have shown that at the moment of development of society, the main contribution to the exposure of the population is made by natural sources of ionizing radiation, while from 50 to 90 % of the dose load are caused by the gas radon-222 (222Rn) and daughter products of its decay. This paper presents the results of radiation-hygienic monitoring of the potentially radon-hazardous territory of the city of Baley, Trans-Baikal Territory. The measurement of the volumetric activity of radon (ОАRn) was carried out in the premises of residential and public buildings by the integral method using track exposure meters REI-4. According to the indicator of the equivalent equilibrium volumetric activity of radon (EROARn), a radiation-hygienic assessment of the premises and the calculation of potential dose loads on the population living in this territory were carried out. Studies have shown that ОАRn in residential and public buildings depends on the geological characteristics of the territory, on the design and design of buildings and structures, and on the building materials used. It was found that the main criterion for assessing the potential radon hazard of territories is the value of ОАRn in rooms on the 1st floors of buildings. According to the degree of potential radon hazard, the territory of the city of Baley can be conditionally divided into 3 types: 1 type - the territory located on a geological fault; Type 2 - the southern part of the city, represented by sedimentary rocks; Type 3 - the northern part of the city, represented by rocks of the basic gabbroid group with a low content of natural radionuclides. The types of buildings and structures and the type of building materials affect the dose load, but do not determine it. © 2021 State Research Center, Burnasyan Federal Medical Biophysical Center of Federal Medical Biological Agency. All rights reserved

РАДИОЭКОЛОГИЧЕСКОЙ МОНИТОРИНГ ПОТЕНЦИАЛЬНО РАДОНООПАСНЫХ ТЕРРИТОРИЙ

In the work the problems of radio-ecological monitoring of territories with potential radon hazard are considered.В работе рассмотрены проблемы проведения радиоэкологического мониторинга территорий с потенциальной радоноопасностью

Estimation of the efficiency of the dry method of decontamination of surface contamination of alpha-emitting-radionuclides

The article describes the evaluation of the efficiency of using the technology of dry method of decontamination of α-radionuclides from working surfaces of premises for different materials, equipment and building structures. Materials and methods. Instruments for measuring of ambient dose equivalent rate (ADER) with a lower limit of 0.03 μSv/h. Specific activity of α-radionuclides in the samples was determined by radiometric, radiochemical and spectrometric methods using standard methods in the accredited laboratory. The measurements in situ were also carried out using the ISOCS «CANBERRA» mobile gamma-ray spectrometry system with high purity germanium detector and a collimator. Technological equipment included industrial vacuum cleaner with nozzles; high-pressure device; packing sets for RAW collection; HEPA filters; personal protective equipment. Results. Maps of spatial distribution of surface α-contamination in the building was constructed. We performed cluster analysis of data for zoning of contaminated surfaces. The decontamination factor for porous (brick, concrete), smooth (wood, brown tiles, laminate) and sticky (bitumen, mastic) surfaces was determined. Conclusion. The cluster analysis made it possible to identify 4 levels of surface α- and β- contamination, particles/cm2 · min: zone I - for α- above 50, for β- above 10,000; zone II - for α- 5-50, for β- 2,000-10,000; zone III - for α- no more than 5, for β- 2000; zone IV - corresponds to the background values of the workspace surfaces. The dry decontamination method revealed a high content of fine dust aerosol fraction deposited in the lungs. To increase the efficiency of dust suppression, water aerosol with droplet size of 100 - 400 microns and quartz sand with particle size of 100-200 microns were sprayed at the rate of 200-400 g per 1 m2. The decontamination coefficient depends on the coating material and the level of surface contamination: concrete - 91 to 97.8%; brick - 85-86%, wood - 38.8-53%; brownstone tiles - up to 29%; mastic - 22-28%; bitumen - 15.9-20%. To protect the personnel, radiation-hygienic rationing of PM10 and PM2,5 content is necessary. © 2019 Izdatel'stvo Meditsina. All rights reserved