According to the Decree of the President of the Russian Federation №585, 13.10.2018, the main approaches to the provision of the radiation safety of the public of the Russian Federation from the use of the sources of ionizing radiation in medicine are the harmonization of the national legislative documents with the international recommendations and the development of the new and improvement of the existing methods of the assessment of the individual patient doses and corresponding radiation risks. The current study was aimed at the justification of the complex of actions to prevent the unnecessary medical exposure of the Russian population. That required to analyze the existing national and international approaches to the assessment of the radiation risks from medical exposure and the results of the existing epidemiological studies, as well as to assess the risks from the most common and/or high dose X-ray examination (computed tomography, interventional examinations, nuclear medicine) for pediatric and adult patients. It was indicated, that these examinations correspond to the “Low” and “Moderate” radiation risk categories. The level of the lifetime radiation risk of cancer morbidity in the Russian Federation for the computed tomography was estimated as 1 case per 3-30 thousand examinations. The performed analysis of the existing international regulatory and methodical documents indicated the significant differences in the practice of the radiation protection in medicine. International practice is mainly based on the practical application of the principle of justification by using the X-ray examination referral guidelines and various methods of risk communication with patients. Main actions to reduce the patient doses and to improve the diagnostic image quality are performed on the hospital level by medical physicists in collaboration with medical staff and representatives of the vendor. It should be noted that dose limits are not applied to the exposure of healthy individuals from screening X-ray examinations. Based on the results of the comparison of the national and international practices of the radiation protection in medicine, both general and specific (for different X-ray modalities) recommendations for the improvement of the system of the radiation protection of the patients and staff were developed. These recommendations should be implemented on practice in the form of the complex program of the optimization of the radiation protection of the public of the Russian Federation from medical exposure. This program can be developed and implemented through the collaboration of the Federal Service of Surveillance on Consumer Rights Protection and Human Well-being and the Ministry of Healthcare of the Russian Federation.

The aim of the current study is to provide a critical analysis of the current hygienic requirements to the design of the PET, PET/CT and PET/MRI centers and departments. The study included the evaluation of the Russian legislative documents containing the requirements for the design of the PET centers and departments, engineering, technological, licensing and other documentation of the working PET centers in St-Petersburg. It was determined, that, despite the existence of the actual direct action document (SanPiN2.6.1.3288-15 “Hygienic requirements on the provision of the radiation safety for the preparation and performance of the positron emission tomography”, it is necessary to consider the hygienic requirements from other legislative documents, hence complicating the process of design and project approval. Some of the actual issues related to the design and allocation of these objects have not been considered in detail: requirements for the transfer platforms for the dispatch and reception of the radiopharmaceuticals, management of the activities and allocation of the mobile PET complexes, etc. Considering the planned increase of the number of PET centers in Russia, it is necessary to further increase and optimize the existing legislation.

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.

In radiological diagnostics and therapy, it is important that practitioners, referrers, (i.e. radiologists, radiation oncologists and others in health-care) are aware of how much radiation a patient may receive from the various procedures used and associated health risk. The profession has a duty to inform patients or their representatives of the advantages and disadvantages of specific investigations or treatment plans. The need to estimate and communicate risks in connection with medical use of ionizing radiation is highlighted e.g. in the Russian Federation State Law No 3, §17.2,1996 and in the EU directive (2013/59/EURATOM 2014). The most commonly used way to express harm in relation to low doses of ionizing radiation is use of the quantity effective dose (E). Effective dose, a radiation protection quantity, however is not intended to provide risk estimates for medical exposures. Its purpose is to optimize conditions for radiation workers (18-65 years) or the general public; all groups with age distributions that differ from patients. In this paper the lifetime attributable risk was used to estimate the excess risk of receiving and dying of radiogenic cancer. The lifetime attributable risk estimations are generated from three different variables, gender, attained age and age at exposure giving the possibility to create age and gender specific cancer risk estimations. Initially, the US Environmental Protection Agency lifetime attributable risk coefficients which are intended to predict the cancer risk from ionizing radiation to a normal US population were applied. In this work, the lifetime attributable risk predictions were modified to the normal Swedish population and to cohorts of Swedish patients undergoing radiological and nuclear medicine examinations or treatments with survival times that differfrom the normal population. For Swedish males, all organs were given the same absorbed dose, exposed at 20, 40 and 70 years, the lifetime attributable risk coefficients (Gy^-1) were 0.11, 0.068, and 0.038, respectively, which is lower than the corresponding figures for US males, 0.13, 0.077, and 0.040. For Swedish females, all organs were given the same absorbed dose, exposed at 40 years of age with a diagnosis of breast, colon or liver cancer, the lifetime attributable risk coefficients are 0.064, 0.034, and 0.0038, respectively, which is much lower than if a 40 years female without known cancer is exposed, 0.073.

The current study is focused on the development of the method of the calculation of the dose quantities required for the assessment or limitation of the ionizing exposure (mean organ doses, effective dose, distribution of the absorbed dose in the critical organ) based on the measured characteristics of the fields of the photon computational (kerma free-in-air, readings of the individual dosimeters) with the energy of 0,02-10 mEv. The dedicated software was developed based on the results of the study, allowing estimating the values of more than 20 mean organ doses, effective dose and the distribution of the absorbed dose in the red bone marrow in 8 computational children and adult models. Additionally, it is possible to calculate the ratios of the effective dose to the readings of the “individual dosimeters”, placed in 48fixed points on the phantom surface. The developed method and software can be used for: (1) calculation of the doses from external exposure and estimation of the level of the radiation injuries in case of the acute radiation exposure of the staff and public; (2) development of the models of the exposure of the staff working in the radiation fields with non-uniform distribution of their characteristics; (3)planning of the countermeasures for the remediation of the consequences of the radioactive contamination (calculation of the routes and working time in contaminated zones); (4) education and training of the staff participating in the investigation and remediation of the consequences of the radioactive contamination.

Objective of the study: to develop a skeleton model for assessing red bone marrow dose from osteotropic beta-emitting radionuclides. This article describes the modeling methodology which takes into account the individual variability of the macro- and microstructure of bone tissue.

Materials and methods: it is proposed to model bone sites with active hematopoiesis by dividing them into small segments described by simple geometric shapes. Spongiosa, which fills the segments, is modeled as an isotropic three-dimensional grid (carcass) of rod-like trabeculae that “run through” the bone marrow. In the process of randomization, multiple carcass deformations are simulated by changing the positions of the grid nodes and the thickness of the rods. Model grid parameters are selected in accordance with the parameters of spongiosa microstructures taken from the published papers. Stochastic modeling of radiation transport in heterogeneous environments simulating distribution of bone tissue and marrow in each of the segments is performed by Monte Carlo method. The model output for the lumbar vertebra is given as an example. The generated vertebral model allowed us to obtain the dosimetric characteristics of bone marrow irradiation, which are comparable to the results obtained with ICRP model developed based on the data of micro-images of bone structures. For the first time ever confidence intervals of dosimetric characteristics associated with individual variability of bone structure were evaluated. The developed methodology for the calculation of doses absorbed in the bone marrow from osteotropic radionuclides does not require additional studies of autopsy material. The obtained results will be used to calculate individual doses in a cohort of Techa riverside residents who were exposed due to Techa River contamination as a result of liquid radioactive waste discharges by the Mayak Production Association.

At the current time radiation therapy units based on the linear accelerators with the energy range of 1823 MeV are common in the Russian Federation. They generate pulsed bremsstrahlung radiation with the maximum energy of approximately 20 MeV. The State Register of measuring devices contains no dosimetry equipment for the measurement of the pulsed bremsstrahlung radiation for such energies. The most common dosimeter of X-ray and gamma radiation, DKS-1123AT, allows measuring the pulsed bremsstrahlung radiation up to 10 MeV, with the main uncertainty of measurement in the range of 3-10 MeV of 50%. No alternative solutions exist at the current time. Although the contribution of this part of the bremsstrahlung radiation spectra is not high, the situation requires actions. However, the State Register of measuring devices includes the DKG-RM1621 dosimeter for the measurement of X-ray and gamma radiation in the energy range of 15 KeV — 20 MeV, but it is now designedfor the measurement of the pulse emissions. The current study is focused on the evaluation of the use of the DKG-RM1621 dosimeterfor the measurement of the pulsed bremsstrahlung radiation and on the estimation of the dose rate range, where the results of the measurements would be valid. The study was performed using the inspection-security complex ST-2630M (JSC “Scantronix systems”) as the source of the pulsed bremsstrahlung radiation with the maximum energy of 3,5 and 6 MeV. This energy range is valid for the DKS-1123AT dosimeter, allowing using it for the comparison. The results indicate that, for the current source,the DKG-RM1621dosimter allows performing the measurements with the additional uncertainty up to 15%, with the mean dose rate of pulsed bremsstrahlung radiation up to 25 µ Sv/h. That is acceptable for the radiation control of the rooms adjacent to the location of a linear accelerator. The use of the additional coefficients to consider the impact of the idle time of the detector on the results of the measurements allows measuring dose rates up to 100 µ Sv/h.

The article provides data on the radiation situation on research results 2008and 2014 in the area adjacent to the site of the peaceful nuclear explosion “Globus-1” before the rehabilitation works (2014—2015), made with a view to removing accidental contamination. The results of the analysis of the dynamics of changes of the radiation situation during the period from 2008 to 2014 year and assess the radiological situation on basic indicators: the values of the dose of technogenic radionuclides content in soil, water and other objects in the environment. On the basis of the research shows that the radiation situation on the territory of the “Globuc-1” has not undergone significant changes from 2008 onwards. An additional dose of man-made exposure of individuals from the population is formed mainly due to external irradiation provided temporary residence on the territory with elevated levels of gamma radiation. As a result of work performed by sealing research wells decreased stem onto the surface of the water with high concentrations of cesium-137, strontium-90 and tritium. Radioactive contamination of the soil to a depth of 1 m, studied in the year 2014, is estimated at 2200 m3 and can be classified as very active and low-level radioactive wastes for which allowed a near-surface burial. Because of the inaccessibility of the area for the removal of soil and remoteness from populated areas considered advisable to arrange the near-surface burial of contaminated soil () directly on the premises of the site.

Despite considerable efforts and significant developments in radiation safety, the risks of radiation incidents in peacetime and wartime remain. Aspects of the ionizing radiation impact on the human body and the clinic of radiation pathology determine the specifics of medical care organization. The most important component of ensuring the readiness of medical institutions and establishments of various ministries and departments to respond to radiation emergencies is the training of medical personnel (health care organizers and doctors of diagnostic and treatment specialty) on radiobiology, clinical radiology, radiation hygiene during the additional professional education (advanced training). The needfor financial and time savings proves the relevance of the use of distance (online) learning technologies. The Institute of Additional Professional Education of the Federal State Budgetary Institution “The Nikiforov Russian Center of Emergency and Radiation Medicine” Ministry of the Russian Federation for Civil Defence, Emergencies and Elimination of Consequences of Natural Disasters has developed the educational program of professional development “Training of medical personnel of EMERCOM of Russia to assist victims of radiation accidents”. The program is included in the System of distance learning of the medical personnel. The program consists of educational and methodical facilities and electronic educational resource, which contain all teaching material and other content to ensure the effective work of students. The main part of the program is implemented remotely with mandatory entrance and intermediate control, and the final on-site part includes seminars, workshops and final certification.

Currently in the Russian Federation the procedure for revision of the national regulatory documents (Radiation Safety Standards (NRB-99/2009) and Basic Sanitary Rules for Ensuring Radiation Safety (OS-PORB 99/2010) has been initiated. In this regard, the authors consider to discuss with the scientific community the necessity to provide amendments in the current Radiation Safety Standards concerning public radiation protection against natural radiation sources, in particular, radon. The main objective is to provide consistence existing national regulatory requirements with the modern international approaches set out in the ICRP and IAEA documents. In this regard, specific proposals on improvement of the regulatory and legislative framework in this field are presented. This will be the basis for the implementation of national radon mitigation strategy in view of the ICRP, WHO and IAEA recommendations and the requirements of the State policy of the Russian Federation in the field of Nuclear and Radiation Safety.