The article examines issues of rehabilitation of facilities and territories contaminated by the man-made and natural radionuclides as a result of past activities of enterprises of nuclear and non-nuclear industries. Rehabilitated facilities and territories contaminated with radionuclides as a result of past activities of enterprises must meet criteria based on the analysis of requirements of existing normative legislative documents in the field of radiation protection of the population taking into account the recommendations of international organizations that are justified dose quantities and derivative indicators used in criteria setting. It is shown that the criteria for rehabilitation of facilities and territories contaminated by man-made radionuclides as a result of past activities, should be the same regardless of whether the contamination occurred as a result of planned activities of the enterprise or due to unauthorized activities. For these situations, the criteria for rehabilitation should be based on dose quantities and derived indicators of the residual contamination of the environment after rehabilitation. Only indicators of radiation safety of the environment can be used in almost all cases for justification of the criteria for rehabilitation of facilities and territories contaminated by natural radionuclides. The article shows that such approaches are applicable not only to environmental media contaminated as result of past activities of enterprises of traditional non-nuclear industries but the mining of uranium and thorium ores. From the standpoint of modern classification of industrial waste with a high concentration of natural radionuclides, the characteristics of these wastes according to their potential radiation hazard to people and the environment are identical.

Tritium is one of the factors of internal exposure of the humans both in occupational and public environments. It enters the body mainly as tritiated water through inhalation, with food, drinks and through the skin; part of tritium gradually transforms into the metabolised organically bound tritium as a result of biochemical reactions. The purpose of this study was to evaluate organically bound tritium contribution to the effective dose of an adult using the biokinetic model and real dosimetric data. The data of long term monitoring from 6 studies with 17 workers or volunteers following single intake of tritiated water in the body were selected from 9 publications (1968-1997). Three two-compartment models of tritium biokinetics were used in this study: recurrent model with gradual transformation of tritium from tritiated water into organically bound tritium and tritiated water excretion; model with instant transformation of tritium into organically bound tritium and tritiated water excretion; model with instant transformation of tritium into organically bound tritium and both tritiated water and organically bound tritium excretion (according to ICRP). The ICRP model doesn’t properly reflect the real tritiated water metabolism in the human body: second exponent of the tritiated water content in the body water and accumulation of the organically bound tritium fraction are absent. The organically bound tritium fraction composes 3% of tritiated water in ICRP model. It is significantly higher compared to two other models (0,4% and 0,8%). According to the first model the contribution of OBT fraction to the mean dose varied from 1,8 to 4,6% for individuals; mean value was 3,0 ± 0,9%. According to the second model the contribution of organically bound tritium fraction was slightly higher: 3,6 ± 1,1%, according to the ICRP model – 9%. The dynamic of excretion of tritium with urine can be described with double-exponential curves and provides the basis for two-compartment modeling. The recurrent model with tritiated water excretion was more adjusted to human physiology. Contribution of organically bound tritium to effective dose can be somewhat higher than that to absorbed dose defined in this work. The presented dose assessment system can be used when specified individual absorbed dose reconstruction in tissues is necessary following accidental intake of large tritium activities.

The aim of this work was to determine the validity of the direct transfer of the recommendations of the ICRP on the nominal risk coefficients and tissue weighting factors in a future revision of the national Radiation Safety Standards (NRB). The article compares the background age and sex distribution, and morbidity and mortality rates of the nominal population, the ICRP used to develop the latest fundamental recommendations, with appropriate indicators for the populations of Russia and Japan as the main source of data for assessment of radiogenic risk in the second half of the last decade. It is revealed that the functions of survival and age-related morbidity and mortality of the Russian population, especially for males, is significantly different from the composite population, while for the Japanese population, the differences are relatively small. The estimates of radiogenic risk coefficients for cancers of various localization using calculation schemes and risk models of the ICRP Publication 103, but based on background data on incidence and mortality of the Russian population were obtained. Baseline incidence and mortality for the Russian population are worse compared to the composite population. Hence, risk coefficients for the Russian population can be taken lower than the recommended ICRP by approximately 20% for the total population and 30% for the persons of working ages. The results clearly demonstrate the inconsistency of the modern criteria of radiation protection, based almost exclusively on the account of carcinogenic effects of ionizing radiation, since it implies that radiation is more harmful for a healthier population. The results also show timeliness of issue of the choice of the calendar period for which the age-dependence of the intensity of cancer incidence and mortality from all causes are taken into account. The article justified the continuation of the discussion of the raised issues, as well as the issues of development the mathematical models used in the estimation of radiogenic risks.

The paper shows, that radionuclides from the stony rocks of uranium mines can be leached by atmospheric precipitations. In acid conditions, a degree of leaching is greater.

Goal. The aim of this investigation was to study the distribution of radionuclides in uranium minings and their impact on the environmental contamination.

Materials and methods. The study was carried out in two stages. In the first stage, a blade of rock was mixed with distilled water in proportions of 0,3 kg of gravel and 1 liter of water. After thirty days of soaking, water was sent to the gamma-spectrometric analysis to Canberra’s spectrometer (USA) with a high-purity germanium detector. In the second stage, we carried out the similar experiment with water, wich was acidified to pH = 3. Contamination levels of areas near the in-situ leaching mine were determined. Intervention levels were used to estimate risk and possible water consumption by the population. Estimations were carried out taking into account the combined presence of several radionuclides in the water.

Results. The results of these studies have shown that the distribution of radionuclides from the source of the contamination is about 360 meters during the 30 y period. The stream, along which samples of soil were collected and studied, was formed by the miner waters that flow along small ruts towards a village, thereby increasing the likelihood of water use by the public.

Conclusions. The uranium mines are the source of radioactive contamination. Radionuclides are distributed due to the erosion of rocks and leached out of the stony rock by precipitations. The extent of leaching is significantly increased in an acidic environment, which takes place near the in-situ leaching mines.

Radon is the major contributor to the background exposure of the population. In the world practice, the radon risk or radon potential mapping are used for the radon dose assessment.

The aim of this work was a radon danger mapping of the Republic of Belarus to assess the radiation situation and determine the radon hazard critical areas.

Materials and methods: The mapping is based on measured values of radon volume activity in the living rooms of different buildings on the territory of the six regions of the Republic of Belarus. We have performed more than 4000 measurements. Integral track radon radiometers based on the polymer Kodak LR-115 film were used to evaluate radon volume activity. Exposure time ranged from 90 to 120 days. The cartogram was built with using the MAPINFO software package.

Results: The low levels of radon concentrations were determined in the Brest and Gomel regions, as well as in the southern districts of Minsk and south-western districts of the Mogilev region. The high levels radon concentrations were determined in some districts of the Vitebsk and Grodno regions, as well as in the north-eastern districts of the Mogilev region. About 2–5 times nonuniformity of radon distribution in settlements of the Republic was observed. The radon hazard critical areas with radon concentrations in the range of 200–400 Bq/m3 were found in some districts of the Vitebsk, Grodno and Mogilev regions.

Conclusions: The radon risk map of the Republic of Belarus gives the possibility to estimate the existing radiation risk. Taking into account the low efficiency of countermeasures long after the Chernobyl accident, it is necessary to increase the level of radiation protection through the radon mitigation activities or to change the radon normative documents.

The article presents the outcomes of the generalized analysis of personnel, patients, and population radiation doses information obtained from the Unified System of Individual Dose Control (USIDC) for 2015. The analysis is conducted on the basis of the annual information from the forms of Federal State Statistical. Observation No.1-DOZ (personnel individual doses), No.2-DOZ (emergency doses), No.3-DOZ (patients’ exposure doses) and No.4-DOZ (population exposure doses from natural and technogenically impacted background). The information is submitted by the organizations and territories accountable to the Rospotrebnadzor. The article presents a comparison with data obtained within the framework of Radiation-Hygiene passportization. In 2015, 16769 organizations providing management with artificial radiation sources submitted the form No.1-DOZ.The form No.1-DOZ contains data on 134 812 personnel individual doses, 123 404 of the personnel group A and 11 408 the personnel group B with personnel monitoring.Iin 2015,the average individual dose for the personnel group A was 1,14 mSv, the personnel group B – 0,79 mSv. In 2015, 11 720 healthcare organizations submitted the form No.3-DOZ. According to the No.3-DOZ data, more than 272 mln X-ray diagnostics were conducted in theRussian Federation in 2015. An average medical radiation dose per capita was 0,48 mSv/year and a mean medical radiation dose per an X-ray examination was 0,26 mSv. In 2015, the form No.4-DOZ contains results of 8 681 measurements of gamma dose rate in wooden houses, 12 642 measurements in one-storey stone houses, 160 174 measurements in multi-storey stone houses and 217 746 measurements on the open ground. Results of 4 441 measurements of radon concentration levels in wooden houses, 5 565 measurements in one-storey stone houses, 61 541 measurements in multi-storey stone houses are given. The population’s average effective dose from natural ionizing radiation sources amounted to 3.44 mSv/year, the average values for the subjects of the Russian Federation fall in the range from 1,6 mSv/year (Sakhalin Oblast) to 11,4 mSv/year (Jewish Autonomous Oblast). The article includes the Annexes with the final generalized forms of the Unified System of Individual Dose Control in 2015 based on the forms of statistical observations No. 1-, 3- and 4-DOZ

The first 5–7 years of the period under review in the history of the Natural Sources Dosimetry Laboratory happened to be in very hard period, which had a time the entire country. A severe funding reduction of the Institute in the 90-s created a threat of loss of the most active and highly professional middle-aged specialists. In these conditions, the only and the most efficient way to maintain Institute as a scientific establishment was to organize the Federal Radiological Center under the guidance of Dr. A.N. Barkovskiy. The Federal Radiological Center consisted of the all physical laboratories, including the Natural Sources Dosimetry Laboratory, without government funding. Nevertheless, as it is shown below, this period was the most fruitful for theoretical and experimental researches, and for development of legal documents and instructional guidance documents. Over these years, more than 10 sanitary regulations and hygienic standards, and more than 20 guidance documents were developed and implemented. Doses of the population due to the natural exposure data-collecting system on the base of federal statistical observation №4-DOZ form were designed. At this period, the first Federal Target Program «Radon» and the System of radiation and hygienic passportization of organizations and territories were developed and authorized. Dr. E.M. Krisiuk was fully engaged in these activities. In these years a great number of non-nuclear companies were examined. Large-scale studies of levels of exposure of the population on specific territories were conducted. The paper examines a summary of the main results, which were obtained in the most important areas of research and practical studies in the period under review.

The goal of the research is to determine relationship between tritium concentration in the body fluid (urine) of people living in the area of influence of the Beloyarskaya NPP and tritium concentration in drinking water.

Materials and methods. Studed population (men and women). Urine samples were collected in the clinical laboratory of a medical unit in Zarechny town. There were 50 individuals in the studied group. Patients were different on age and weight. Water samples were collected in an arbitrary way, through the all study period, from October to November in 2015 year. Tritium concentrations were determined with the ultra-low level liquid scintillation spectrometer Quantulus-1220 (USA). The facility developed by L.G. Bondareva was used for tritium extraction. The method allowes to separate the template, which significantly effects determination of tritium.

Results. The urine samples from people living in the area of influence of the Beloyarskaya NPP in Zarechny town were analyzed in the study. There was positive relationship between tritium concentration in drinking water and tritium concentration in urine. Statistically significant correlation between analyzed parameters was found (correlation coefficient 0.98; significance level 0,007). Individual doses were estimated according to Harrison, Khursheed, Lambert. The Doses vary from 0,32 to 1,12 with an allowance for consumption of drinking water 100 l y–1 (according to the consumption standard for the analyzed region), which amounts 0,032–0,12 % from dose limit for population (1 mSv y–1). It was determined what drinking water is the main source of the radionuclide in human body in this region. The determined values of tritium concentration in drinking water are significantly lower than the intervention level for tritium of 7600 Bq l–1 ( Radiation Safety Standards-99/2009, Appendix 2a).