The paper (in two parts) presents an overview of the new guidelines MR 2.6.1.0333-23 (approved on 01 December 2023) that supersede guidelines MU 2.6.1.2838-11, which were used for organizing radiation surveys of residential, public and industrial buildings and facilities and their sanitary assessment in terms of radiation safety indicators over the past 12 years. Due to a large number of critical comments on the document received during this period, a need for significant revision emerged. The scope of the revised document was expanded, and now it covers all stages of the life cycle of buildings and facilities: commissioning; operation period; overhaul and reconstruction; demolition. In the second part of the paper, numerous innovations are considered in terms of estimating the indoor average annual equilibrium equivalent concentration of radon isotopes. The reasons for the introduction of certain changes are outlined. Based on the results of previous studies and the review of foreign recommendations, the procedures for measuring indoor radon concentrations have been improved in such a way as to balance the increase in the reliability of estimating the average annual equilibrium equivalent concentration of radon isotopes and the increase in time and labor costs for testing laboratories to conduct the survey. The revised document introduces separate procedures for measuring indoor radon concentrations in new buildings and existing buildings with round-the-clock and non-round-the-clock occupancy. Estimating a weighted average based on the results of two-season measurements will represent a significant step forward in assessing the actual average annual radon concentrations in operated buildings in Russia. At the same time, the case of radiation survey of the buildings within the framework of events with legally limited duration is considered separately in the revised document. Taken together, the changes should have a positive impact on the quality of measurement information obtained by testing laboratories and underlying decisions made by executive authorities.

The paper (in two parts) presents an overview of the new guidelines MR 2.6.1.0333-23 (approved on 01 December 2023) that supersede guidelines MU 2.6.1.2838-11, which were used for organizing radiation surveys of residential, public and industrial buildings and facilities and their sanitary assessment in terms of radiation safety indicators over the past 12 years. Due to a large number of critical comments on the document received during this period, a need for significant revision emerged. The scope of the revised document was expanded and now covers all stages of the life cycle of buildings and facilities: commissioning; operation period; overhaul and reconstruction; demolition. In the first part of the paper, the structure and legal status of the new guidelines are considered, as well as the main innovations in terms of measuring the ambient dose equivalent rate of gamma radiation, searching and identifying local radiation anomalies and sites of radioactive contamination, measuring surface contamination levels, and determining the minimum number of premises to be surveyed. The reasons for the introduction of certain changes are outlined. The issues of evaluation of measurement uncertainty, reporting of measurement results and registration of test reports are covered in detail. In the second part of the paper, numerous innovations will be considered in terms of estimating the indoor average annual equilibrium equivalent concentration of radon isotopes.

A comprehensive radiation survey of settlements in six districts of the eastern part of the Orenburg region in terms of exposure to natural sources of ionizing radiation, carried out in 2019, revealed numerous exceedances of the hygienic norm (action level) for indoor radon concentration in residential and public buildings. It was found that among other studied factors, exhalation of radon from the ground under the buildings is the main source of high levels of public exposure. Due to the lack of funding for the continuation of the survey in 2020, specialists of St. Petersburg Research Institute of Radiation Hygiene after Professor P.V. Ramzaev, Directorate of Rospotrebnadzor in the Orenburg region and the Center of Hygiene and Epidemiology in the Orenburg region needed to develop new approaches to survey planning. These new approaches should provide maximum amount of measurement information necessary to ensure radiation safety of the region’s population, with minimal financial investments and labor costs. Indoor radon concentration in residential and public buildings was undoubtedly chosen as the studied factor, and the integrated measurement method using SSNTDs was chosen as the most suitable method for the objectives of the survey due to its scalability and ease of detectors deployment. Since exposure to radon and its progeny is the second leading cause of lung cancer after smoking, the selection of priority districts of the region for the radon survey was based on average standardized trachea, bronchi, and lung cancer morbidity rates in the districts of the Orenburg region for 2009-2018. The survey conducted in 2020-2023 revealed exceedances of the hygienic norm (action level) for indoor radon concentration in five of seven surveyed districts. By 2025 it is planned to conduct radon surveys in three more districts of the Orenburg region with increased respiratory systems cancer morbidity rates.

According to Rosstat statistics, in recent years there has been a tendency in the Russian Federation to increase the intensity of construction, while both the number of buildings put into operation and their total area are increasing. The assessment of the potential radon hazard of land plots for construction provides the possibility of timely inclusion of the necessary protective (preventive) measures against radon in the design of buildings. This is a legal requirement in cases where the density of radon flux from the ground surface within the building area exceeds the established hygienic standards (action levels). The paper presents a review of Russian and foreign approaches to assessing the potential radon hazard of land plots conducted within the framework of engineering and environmental surveys. The current regulatory requirements to radiation safety indicators of land plots for construction of residential, public and industrial buildings and facilities in the Russian Federation are analyzed. The main drawbacks of the algorithm for determining the potential radon hazard of land plots, used in the current guidelines MU 2.6.1.2398-08 approved at the federal level more than 15 years ago, are described. Critical remarks (the unsuitability of the value of density of radon flux from the ground surface for designing radon protective and mitigation (remedial) measures, lack of consideration of seasonal variations of radon flux density, etc.) accumulated over the years as a result of practical application of these guidelines are presented. Benefits and drawbacks of foreign approaches to assessing the potential radon hazard of the territory based on the results of measurements of radon concentration in soil gas, as well as the very possibility of a transition in Russian regulations from the density of radon flux from the ground surface to the radon concentration in soil gas, are analyzed. Some rational proposals of various Russian research teams on improving the algorithm for determining the potential radon hazard of land plots are considered.

The aim of this study was to evaluate the activity of 225 Ac in urine of patients undergoing radionuclide therapy with 225 Ac-DOTA-TATE. Activity concentration was determined in the urine samples collected within 72 hours after injection of 225 Ac-DOTA-TATE, using the ORTEC semiconductor gamma spectrometer, model TSP-DX-100T-PAC-PKG-1. Calculation of excreted activities was additionally performed based on scintig- raphy scans of patients receiving 225 Ac-DOTA-TATE. Scans were conducted 5 times for each patient: immedi- ately after injection, at 4 hours, and on the 1st, 2nd, and 3rd days after injection of the radiopharmaceutical. Absolute activity values and fractions of the injected activity were calculated based on the specific activity values. The results of the calculated activity concentration values demonstrate that maximum excretion was observed within the four hours after 225 Ac-DOTA-TATE injection. Significant differences between the two methods of determining 225 Ac activity were observed only on the third day after radiopharmaceutical injection, which allows for the simplification of future experimental work by using indirect radioactivity measurement methods for activity calculations. There were no significant differences between patient groups with different number of 225 Ac-DOTA-TATE injection, which allows for the exclusion of this parameter in the evaluation of experimental results. The results of this study represent the first published experimental data on the determi- nation of actinium excretion in patients.

INTRODUCTION: Peptide receptor therapy based on the 225 Ac radionuclide, due to the targeted effect on tumor cells, is the most promising method of treatment for patients with generalized forms of neuroendocrine tumors and castration-resistant prostate cancer. OBJECTIVE: The aim of the work was to evaluate the effectiveness of radioligand therapy of medicinal radiopharmaceuticals with 225 Ac. MATERIALS AND METHODS: Radioligand therapy based on 225 Ac radionuclide was performed in 7 patients with generalized prostate cancer and 3 patients with neuroendocrine tumors. RESULTS: Systemic radiation therapy with 225 Ac-PSMA 617 and 225 Ac-DOTATE showed its effectiveness in clinical practice — patients have a decrease in the level of accumulation of the radiopharmaceutical (RP) in pathological foci on PET-CT with 68 Ga-PSMA and 68 Ga-DOTATE; a decrease in the level of prostate-specific antigen (PSA) in the blood (for prostate cancer); reduction of manifestations of asthenic, pain and carcinoid (for neuroendocrine tumors) syndromes. Dosimetric studies make it possible to assess the biodistribution of a radiopharmaceutical drug in the body, accumulation in target organs and lesions. CONCLUSION: The appointment of this type of treatment requires an integrated approach based on a thorough study of medical records, assessment of the receptor status of the tumor tissue, timely detection and prediction of adverse reactions.

The paper presents the estimated doses to the population of six eastern districts of the Orenburg region, Russia, based on the results of a comprehensive radiation survey conducted in 2019 in 34 settlements with previously found elevated levels of activity concentration of natural radionuclides in tap water from ground water sources of drinking water supply. It is shown that the average individual annual effective dose due to all natural sources of ionizing radiation in 18 of 34 settlements corresponds to ‘elevated level’ of exposure due to natural sources according to established classification (from 5 to 10 mSv/year), and in another 7 settlements to ‘high level’ (over 10 mSv/year) with radon being the main contributor to the dose. Four settlements of Kvarkensky and Adamovsky districts, where the highest indoor radon concentrations had been found, were selected for a detailed survey, which included measurements of density of radon flux from the soil, radon concentration in soil gas, activity concentration of natural radionuclides in samples of building materials and in soil samples, and activity concentration of radon in tap water from groundwater sources of drinking water supply. Results of the detailed survey proved that the main source of radon in the buildings was the soil gas infiltration; compared to it, the contribution of waterborne radon release was insignificant.

This study presents results of radiation-hygienic surveys of the Bryansk Oblast settlements bordering the Republic of Belarus. The data were obtained in the course of implementation of measures of the “Program of joint activities of Russia and Belarus within the framework of the Union State for the protection of the population and rehabilitation of the territories affected by the Chernobyl NPP accident” in 2019–2022. The first part of the study presents a general characteristic of the current state of the problem of returning the residents of radioactively contaminated territories to normal living conditions and provides information on the settlements of the surveyed region. The modern demographic composition of the population is considered; the structure of private subsidiary plots is investigated. The results described in this part of the study indicate the main ways, which are relevant for the formation of the internal exposure dose of the public at the current stage of the radiation accident.

The paper presents results of a comprehensive radiation survey conducted in 2019 in six districts of the eastern part of the Orenburg region in 37 settlements with previously found elevated levels of activity concentration of natural radionuclides in tap water from groundwater sources of drinking water supply. The survey included measurements of indoor radon concentrations and EEC in residential and public buildings, as well as measurements of ambient dose equivalent rate of gamma radiation indoors and outdoors. The survey revealed that annual average indoor radon EEC in many residential buildings in 23 settlements and public buildings in 25 settlements exceeded the hygienic norm (action level) of 200 Bq/m3 adopted in Russia for existing buildings. The highest values of annual average indoor radon EEC were obtained in residential buildings in Novovinnitskoe (1242 Bq/m3), Bratslavka (987 Bq/m3) and Anikhovka (942 Bq/m3) in Adamovsky district, and in public buildings in Kvarkeno (2291 Bq/m3) in Kvarkensky district, Karabutak (1114 Bq/m3) and Novovinnitskoe (923 Bq/m3) in Adamovsky district. The established hygienic norms in terms of ambient dose equivalent rate indoors and outdoors were not exceeded in the surveyed settlements. Results of the survey showed that the main reason for high indoor radon concentrations in residential and public buildings in the settlements of the eastern part of the Orenburg region is not related to the usage of tap water from groundwater sources of drinking water supply with elevated levels of activity concentration of natural radionuclides.

The article deals with the issues of normative and methodological support of radiation survey of buildings and structures to be demolished. It is noted that with the intensive growth of construction of dwellings and public buildings in large cities, former industrial territories with a significant number of facilities to be demolished are being included into the development zone. The radiation monitoring and sorting of industrial waste generated after the demolition of buildings is not feasible in practice. The expediency of radiation survey of buildings and structures to be demolished at the stage preceding their dismantling, as well as the need to develop and approve at the federal level the methodology of its implementation is substantiated. Recommendations for the assessment of radiation safety indicators of buildings and structures to be demolished are given. It is shown that if the value of ambient equivalent gamma dose rate in the buildings and structures to be demolished does not exceed 0.6 μSv/h, industrial waste generated after demolition of buildings and structures and containing only natural radionuclides are not a subject to any restrictions related to the radiation factor, since the value of effective activity concentration of natural radionuclides is guaranteed not to exceed 1500 Bq/kg and therefore the waste is classified as Category I in accordance with the Basic sanitary rules for the provision of radiation safety (OSPORB 99/2010).

At the 2018 FIFA World Cup held in our country, great attention was paid to ensuring radiation safety. When holding mass events, there are risks of terrorist attacks that need to be taken into account. Therefore, the use of radiation monitoring systems during this period is primarily aimed at countering radiation terrorism. This article reviews the equipment and personnel of the Rospotrebnadzor radiation control laboratories in the regions of the Russian Federation that participated in the 2018 FIFA World Cup for readiness to perform the task of responding to cases of activation of radiation control systems. In addition, a comparative description of the radiation monitoring systems used during the 2018 FIFA World Cup and the experience of their operation at pedestrian inspection points located on the border of the security perimeter of stadiums are provided.

According to the analysis of requests for methodological assistance to the Saint-Petersburg Research In ­stitute of Radiation Hygiene after Professor P. V. Ramzaev, measurements of radon concentration (or radon EEC) in existing operated public buildings (primarily children institutions) in the framework of surveillance actions in the regions of the Russian Federation, as a rule, are taken according to Guidelines MU 2.6.1.2838-11, intended for radiation control of public buildings only when they are put into operation after construction, major repairs or reconstruction, due to the absence of special guidelines. Compliance with the requirements of paragraph 6.5 of MU 2.6.1.2838-11 means that the building and premises are in a state that is not equal to their normal operation mode. Registration of high values of indoor radon concentration in this case leads to management decisions, including administrative suspension o f activities for up to ninety days, i.e. the closure of individual premises or even the entire building of a children institution. The consequences of making such decisions may include an increase in social tension in society and provoking radiophobia among the population. The paper presents specific recommendations for the radon survey for existing operated public buildings with non-round-the-clock stay of people, which are based on the results of the analysis of the experience of practical application of various methods of measuring indoor radon concentrations in such buildings in order to assess average radon concentration during working hours in the normal operation mode. The proposed approach can be further used as the basis for developing special guidelines for radiation control of existing operated public buildings with non-round-the-clock stay of people.

According to the analysis of requests for methodological assistance to the Saint-Petersburg Research In ­stitute of Radiation Hygiene after Professor P. V. Ramzaev, measurements of radon concentration (or radon EEC) in existing operated public buildings (primarily children institutions) in the framework of surveillance actions in the regions of the Russian Federation, as a rule, are taken according to Guidelines MU 2.6.1.2838-11, intended for radiation control of public buildings only when they are put into operation after construction, major repairs or reconstruction, due to the absence of special guidelines. Compliance with the requirements of paragraph 6.5 of MU 2.6.1.2838-11 means that the building and premises are in a state that is not equal to their normal operation mode. Registration of high values of indoor radon concentration in this case leads to management decisions, including administrative suspension o f activities for up to ninety days, i.e. the closure of individual premises or even the entire building of a children institution. The consequences of making such decisions may include an increase in social tension in society and provoking radiophobia among the population. The paper presents specific recommendations for the radon survey for existing operated public buildings with non-round-the-clock stay of people, which are based on the results of the analysis of the experience of practical application of various methods of measuring indoor radon concentrations in such buildings in order to assess average radon concentration during working hours in the normal operation mode. The proposed approach can be further used as the basis for developing special guidelines for radiation control of existing operated public buildings with non-round-the-clock stay of people.

Starting from 2014, several cases of exceedance of the specific total alpha-activity of the natural radionuclides and specific activity of 222Rn were identified in the water of the underground wells in the eastern districts of the Orenburg region. Based on the results of the surveys, a number of settlements were equipped with the systems of aeration of water from underground wells prior to the distribution, but significant expenditures on the technical maintenance of the aeration units lead to their frequent malfunctions. Based on the results of the surveys of the drinking water in settlements of the Adamovskiy, Kvarkenskiy, Novoorkskiy, Dombarovsky, Svetlinsky districts and Yasnenskiy urban district, it was estimated that in some settlements specific activity of 222Rn in drinking water exceeded the intervention levels up to a factor of 10. No exceedances of intervention levels for 226Ra, 224Ra, 228Ra, 210Pb, 210Po and 238U were identified. Based on the results of experiments and analyses the authors performed the hygienic assessment of the indicators of the radiation safety of the drinking water from the underground water supply sources in several settlements in the eastern districts of the Orenburg region, performed the analysis of the effectiveness of the aeration systems, developed recommendations on the provision of the radiation safety of the public of the eastern parts of the Orenburg region for the use of the drinking water from the underground water supply sources and developed proposals on the improvement of the limitation of concentration of 222Ra in drinking water.

To justify the decision on the necessity of the execution of the remediation actions or public safety measures as well as the correspondence of the remediated territories to the established criteria or reference levels it is necessary to correctly perform the assessment of the doses of the public residing in the zone of influence of the facilities of the nuclear and radiation legacy. Currently, there is no legislative document, regulating the doses of that category of the public. Based on the result of the regulatory documents and scientific publications on the radiation surveys of the contaminated territories and assessment of the doses to the public residing in the surveillance zone of the radiation facilities, on the radioactively contaminated territories and exposed by natural radionuclides, it was estimated that approaches, models and equations for the estimation of the doses from man-made and natural radionuclides can be applied for the public residing in the zone of influence of the facilities of the nuclear and radiation legacy. The number of control measurement points and samples for the radiation survey of the territories of the limited scale should be sufficient for the representative assessment of the doses to the public.

To justify the decision on the necessity of the execution of the remediation actions or public safety measures as well as the correspondence of the remediated territories to the established criteria or reference levels it is necessary to correctly perform the assessment of the doses of the public residing in the zone of influence of the facilities of the nuclear and radiation legacy. Currently, there is no legislative document, regulating the doses of that category of the public. Based on the result of the regulatory documents and scientific publications on the radiation surveys of the contaminated territories and assessment of the doses to the public residing in the surveillance zone of the radiation facilities, on the radioactively contaminated territories and exposed by natural radionuclides, it was estimated that approaches, models and equations for the estimation of the doses from man-made and natural radionuclides can be applied for the public residing in the zone of influence of the facilities of the nuclear and radiation legacy. The number of control measurement points and samples for the radiation survey of the territories of the limited scale should be sufficient for the representative assessment of the doses to the public.

The paper presents the activities of Rospotrebnadzor to ensure radiation safety in the framework of nuclear and radiation terrorism counteractions during the FIFA World Cup 2018 in Russia. One of the main activities of Rospotrebnadzor was to ensure radiation safety of food and drinking water. This task was solved by placing stationary radiation monitoring systems and organizing of continuous radiation monitoring of all foodstuffs and drinking water incoming to all sports facilities. In addition, selective radiation monitoring of samples of cooked food and drinking water at the catering facilities of the stadiums was organized. The second important activity was to ensure the radiation safety at the sites of mass people crowding with the use of portable equipment and/or car-borne radiological laboratories. The third activity was the identification and examination of the identified sources of ionizing radiation in case of alarm of radiation monitoring systems. The last but not the least activity was the interdepartmental cooperation, the effectiveness of which directly affects the response and resolution of issues related to emergency situations or situations that threaten radiation safety. The paper also briefly described the activities of the Saint-Petersburg Research Institute of Radiation Hygiene after Professor P.V. Ramzaev in the framework of ensuring radiation safety at the FIFA World Cup 2018.

This study is focused on the main activities on provision of the radiation safety as a part of sanitary surveillance and radiation terrorism counteraction during the 2018 World Football Championship. The main activities at the preparatory stage are collection and analysis of information on the potentially dangerous sources of ionizing radiation in the regions of the Russian Federation hosting the 2018 World Football Championship; control of compliance to the sanitary rules of the projects of the allocation of X-ray screening units and their commissioning; radiation control as a part of the commissioning of the sport facilities after construction/reconstruction; sanitary control of the allocation of X-ray screening units on the sport and infrastructure facilities; organization-methodical activities. During the World Football Championship it is planned to carry out the radiation control in monitoring points and the control of the concentration of radionuclides in water and food stuff samples. In the framework of the radiation terrorism countermeasures, the main activities of the provision of the radiation safety are the radiation control on the infrastructure facilities, remote points of inspection and entry points to the sport facilities; full-time emergency preparedness. A brief evaluation of the equipment of the Rospotrebnadzor radiation control laboratories in the regions of the Russian Federation hosting the 2018 World Football Championship and their preparedness for the provision of the radiation safety is also presented in the paper.

According to the Federal target program “Provision of the nuclear and radiation safety in 2016-2020 and up to 2030”, activities on the liquidation of the nuclear legacy are performed in the Russian Federation. The nuclear legacy includes mines, pits, industrial facilities, burrows and tailings of the uranium processing facilities (objects of uranium legacy), objects of extraction and processing of precious and rare elements and mineral ore, producing the wastes with the increased concentration of natural radionuclides. Due to the damage or lack of the barriers, preventing the distribution of radionuclides, natural radionuclides contaminate the environment and expose the population residing in closely located communities. Radionuclides of radium ( 226Ra and 228Ra), radon (222Rn) and their daughter have the main contribution to the doses and corresponding radiation risks to the public residing in a vicinity of such facilities. According to the Russian legislative documents, exposure of the public residing in the area of location of the objects of the uranium legacy and objects and territories, contaminated by the natural radionuclides due to the past activities of the non-nuclear facilities is attributed to the natural exposure with the subsequent compliance to the requirements of NRB 99/2009 and OSPORB 99/2010 on limitations of natural exposure. The main direction of the use of the objects and territories contaminated by the natural radionuclides due to the past activities of nuclear and non-nuclear facilities is their unlimited use for the industrial purposes. The main criteria for the unlimited use of remediated areas and territories of buildings and constructions are the requirements of NRB-99/2009 and OSPORB-99/2010 for the construction of the residential and public buildings. The criteria of NRB-99/2009 and OSPORB 99/2010 for the industrial buildings would be applied for the use of the remediated areas and territories of buildings and constructions with the residual contamination by the natural radionuclides.

The Chernobyl accident in 1986 is one of the most large-scale radiation accidents in the world. It led to radioactive contamination of large areas in the European part of the Russian Federation and at the neighboring countries. Now, there are more than 4000 settlements with the total population of 1.5 million in the radioactively contaminated areas of the Russian Federation. The Bryansk region is the most intensely contaminated region. For example, the Krasnogorskiy district still has settlements with the level of soil contamination by cesium-137 exceeding 40 Ci/km 2 . The regions of Tula, Kaluga and Orel are also significantly affected. In addition to these four regions, there are ten more regions with the radioactively contaminated settlements. After the Chernobyl accident, the affected areas were divided into zones of radioactive contamination. The attribution of the settlements to a particular zone is determined by the level of soil contamination with 137 Cs and by a value of the average annual effective dose that could be formed in the absence of: 1) active measures for radiation protection, and 2) self-limitation in consumption of the local food products. The main regulatory document on this issue is the Federal law № 1244-1 (dated May, 15 1991) "On the social protection of the citizens who have been exposed to radiation as a result of the accident at the Chernobyl nuclear power plant". The law extends to the territories, where, since 1991: 1) the average annual effective dose for the population exceeds 1 mSv (the value of effective dose that could be formed in the absence of active radiation protection measures and self-limitation in consumption of the local food products); 2) soil surface contamination with cesium-137 exceeds 1 Ci/km 2 . The paper presents results of calculations of the average effective doses in 2017. The purpose was to use the dose values (SGED 90 ) in zonation of contaminated territories. Therefore, the calculations have been done under the assumption that the doses were formed in the absence of active radiation protection measures and self-limitation in consumption of the local food products. The dose to population, rather than the density of radioactive contamination of soil by 137 Cs, is the most objective characteristic of the actual radiation exposure to the residents of the contaminated areas.