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

Comprehensive radiation survey and public health assessment in the vicinity of NPP

Aim. For many years, SRC-FMBC carried out comprehensive monitoring of radiation-hygienic situation in order to assess the dynamics of the measurement of the environmental media, public health and to develop health and epidemiological measures to assure the public welfare. Matherial and methods. The radiation-hygienic conditions of the environment are assessed by comparing the obtained results with the regional background values. Result. The radionuclide concentrations in the environmental media within the NPP supervision area do not exceed typical regional background values. We studied the radionuclide concentrations in some foodstuffs of plant and animal origin, drinking water and other environmental media. The concentrations of 137Cs and 90Sr in foodstuffs are the same as in the similar foodstuffs from other regions and the whole Russia. This is due to global precipitation of 137Cs and 90Sr following the nuclear weapons tests and accident at the Chernobyl NPP of 1986. Conclusion. According to analysis of the main health indicators of the public living around the NPP, general state of the adult and children public is healthy. There is no impact of the NPP on negative trends in some changing indicators of the adult and children public health

Monitoring of radiation hygienic situation in the area of the Argun production mining and chemical association

The Argun Production Mining and Chemical Association is a multi-activity mining company which perfprms mining of uranium ore, carries out refining of such ores in hydrometallurgical process to produce natural uranium oxide. In order to establish the strategy and develop criteria for the site remediation, independent radiation hygienic monitoring is being carried out over some years. The researches performed showed that there is a significant excess of 226Ra and 232Th content compared to areas outside the zone of influence of uranium mining