Radiation Safety Problems Research Articles

EVALUATION OF TECHNOLOGICAL PLASTICITY OF HIGH BORON CORROSION-RESISTANT STEEL DURING HOT DEFORMATION OF PIPES USED FOR SPENT NUCLEAR FUEL STORAGE

Statement of the problem. The sustainable development of the global nuclear power industry in the future depends on how effectively the problems of radiation safety and nuclear proliferation are addressed. Such problems occur, among other things, at the final stage of the nuclear fuel cycle – spent fuel management. This task is currently on the agenda of both the international community and national governments of countries that develop or intend to develop nuclear energy [1−3]. Today, in connection with ensuring the safety of nuclear energy, boron-containing steels are widely used in the world practice as a material for biological protection and for the manufacture of special equipment parts. This is due to the fact that the B10 isotope in steels provides neutron capture [4]. Hexagonal pipes made of high-boron steel were needed to shield the support cover of the compacted spent fuel storage facility at nuclear power plants. Corrosion-resistant steels alloyed with boron are widely used in the nuclear power industry due to their special nuclear properties. During the operation of nuclear power plants, fuel assemblies that have served their useful life must be stored in special storage facilities using containers – hexagonal tubes made of 04Сr14Ti3B2V steel. To reduce costs during in the construction and operation of NPPs, part of the spent nuclear fuel management should be performed at Ukrainian enterprises. This will provide a significant import substitution effect. To manufacture hexagonal tubes from 04Сr14Ti3B2V steel according to the ingot-hot deformation-profiling-heat treatment scheme, it is necessary to develop the parameters of hot deformation and subsequent technological operations. The use of these pipes in compacted spent fuel storage facilities of NPPs will allow to increase the storage capacity by 2 times, which will give a significant national economic effect Material and methods of research. Material used for the study was steel 04Сr14Ti3B2V (CS-82), smelted using two variants (vacuum-induction – “VI” and vacuum-induction followed by vacuum-arc remelting – (“VD”). Steel grade 04Сr14Ti3B2V belongs to high-alloy, corrosion-resistant ferritic steels with a high boron content of up to 2 %. The method of differential thermal analysis was used to study the phase transformation temperatures in the steel. X-ray diffraction and micro-X-ray spectral analysis were used to assess the phase state. The steel samples were tested for weldability After cooling, the welded samples were subjected to X-ray transmission [5]. Hot twisting tests and mechanical tests at high temperatures were also performed. The macro- and microstructure of the metal was studied. Results. The macro- and microstructure of steel was evaluated depending on the smelting method. The phase composition of the steel was studied. The study of the plastic properties of steel ChS-82 by means of penetration and hot twisting tests showed that the temperature range of maximum plasticity is in a wide range (from 1 025 to 1 150 0C) with a rather low resistance to deformation. During hot deformation in the temperature range of 1 175 0C and above, metal fracture was observed along the grain boundaries at the melting points of the Cr−Fe−B boride phase. The optimal temperature range for hot deformation of steel ChS-82 is 1 000−1 050 ⁰С. Scientific novelty. For corrosion-resistant high boron steel used for spent nuclear fuel storage, the temperature range of hot deformation was selected and the structural and phase composition was estimated, which will allow deforming the metal on the piercing mill and manufacturing pipes.

Radiation safety problems during the patient traveling by public transport after radiopharmaceutical therapy with 131I

Radiopharmaceutical therapy with 131I has been one of the most common types of radiopharmaceutical therapy for many years. Radiation safety of the public is ensured by limiting the patient contacts until the radiological parameters are reduced to the established criteria. To increase the availability of the radiopharmaceutical therapy with 131I, softer patient release criteria for 131I have been proposed. However, early patient release may increase exposure to the public, e.g. in transport. The aim of the work is to evaluate the radiation exposure from patients with 131I -MIBG and Na131I on the public in transport considering the generation of biological waste. In this work, 131I excretion from the body of patients in transport was evaluated for different scenarios of patient travel to the place of residence. As a result, it was found that mitigation of patient release criteria leads to an increase in the effective dose to the public in transport and an increase in the 131I activity excreted with patient waste. The specific activity in the tanks of biotoilets in transport, generated after the pas -sage of a patient with injected 131I -labeled radiopharmaceuticals, exceeds the limit value of classifying liquid waste as radioactive. To optimize radiation protection of the public, it is advisable to apply a differentiated approach to release patients after therapy with 131I: to group non-resident patients into a separate category retaining for them the established release criterion (without mitigation) to minimize the radiation impact on the public.

A new deep eutectic solvent based on diphenylguanidine for the effective extraction of pertechnetate anion

In this work, for the first time, a new class of deep eutectic solvents has been synthesized and applied for the efficient extraction of pertechnetate anion from imitators of real media from which pertechnetate removal is needed: high-level waste imitator and sea water imitator. Diphenyl guanidine was studied as a hydrogen bond acceptor, which exhibits a high extraction ability for pertechnetate anion separation. Natural fatty acid and natural terpene were studied as hydrogen bond donors. The structure, properties, viscosity and stability of the obtained eutectic solvents were studied. Also, the radiation resistance of the obtained solvents was studied from the point of view of distribution ratio saving. It was shown that the new class of solvents has a high radiation resistance and efficiently extracts pertechnetate anion even from acidic media in high-temperature extraction process and can be the first step platform for solving technological and radiation safety problems.

Метод оценки радиационных рисков смертности ликвидаторов чернобыльской аварии, учитывающий возможные ошибки в постановке и регистрации диагнозов причин смерти

In the past decade the lawful use of radiation risks of non-cancer diseases estimates to solve ra-diation safety problems has become more significant. The highest statistical power of low dose (less than 0.2 Gy) radiation risks research is possible in the cohort of the Chernobyl clean-up workers (liquidators) registered and been under medical monitoring in the system of the National Radiation Epidemiological Register (NRER) since 1986. The liquidators total number exceeds 130 thousand people. Because of the large-scale annual collection of health data, carried out in the NRER system, verification of the diseases diagnoses and medically certified causes of death, a natural question of radiation risk estimates compatibility with consideration to probable errors in a disease diagnosis and cause-of-death reporting on death certificates arises. The work is aimed at estimating the radiation risk of mortality from diseases of the circulatory system and diseases of the digestive organs in the Russian cohort of liquidators, with account of possible errors in the disease diagnosis and certified causes of death. The size of the cohort considered for mortality analysis was 91,013 people, the average age at the Chernobyl zone entry was 33.6 years, average radiation dose was 0.133 Gy. In this study, the method of maximizing the partial likelihood function was used to assess radiation risks, with consideration of individual radiation doses to liquidators and the assessment of background mortality using the Breslow method. The specificity of the diagnosis of the primary causes of death in the NRER system significantly exceeds the level of 0.99. Considering the specificity index of 0.99, the estimates of radiation risk coefficients ERR/Gy for mortality from diseases of the circulatory system and diseases of the digestive system in the cohort of Russian liquidators do not differ from the estimates obtained in the assumption that there are no first kind errors (false positive diagnosis) in the diagnoses of the primary causes of death in the NRER database. The results obtained confirm the high stability and validity of the assessments of radiation risks of mortality from diseases of the circulatory system and diseases of the digestive system, obtained earlier from the data on liquidators registered in the NRER.

Can activated carbon filtration of groundwater cause radiation safety problems?

Abstract Activated carbon filtration is commonly used to remove groundwater contaminants in water utilities. During its use, also groundwater radon is adsorbed on activated carbon where it radioactively decays to Pb-210 within a few days. The intermediate stages of radioactive decay produce gamma radiation outside the filter, which can be harmful to health. In addition, EU legislation sets a clearance level of 1 kBq/kg for the Pb-210 concentration of waste, above which disposal of carbon waste can be complicated, depending on national legislation. This study focused on activated carbon filters from two groundwater plants. Measurements were made over the service lifetime of the activated carbon and included measurements of adsorption of radon from water to carbon, radiation dose rates outside the filters and Pb-210 concentrations in the carbon. The study observed a rapid decrease in the radon adsorption rate of activated carbon during the first year of use. This phenomenon has a significant effect on the concentration of Pb-210 in the activated carbon waste at the end of service life. The calculated forecast model clearly showed that the risk of exceeding the clearance level of Pb-210 increases if the radon concentration in the raw water exceeds 100 Bq/L.

Modern technical and software-analytical tools for solving problems of radiation and technogenic-ecological safety of Ukraine

Nuclear energy in Ukraine is provided by the operation of four operating nuclear power plants (15 reactors). For the next decades it is planned only to increase the capacity of this according to the “Energy Strategy of Ukraine until 2035” industry. Nuclear power plants are objects of increased danger. So, conditions should be provided to maintain environmental balance in Ukraine, innovative developments for radioactive waste management should be implemented, methods of wastewater treatment must be developed/improved, prevention and elimination of natural and emergency emergencies should be provided. It is important to create variety of scientific, technical and innovative developments to solve these problems. Their development is carried out by institutions and organizations, including the National Academy of Sciences of Ukraine. The study analyzes and summarizes activities of the State Institution “The Institute of Environmental Geochemistry of National Academy of Sciences of Ukraine” on innovative developments to improve nuclear, radiation and technogenic environmental safety. The developments of the Institute are defined, described and systematized. The performed research was aimed to solve problems of sustainable development of nuclear energy, environmental problems of nuclear fuel cycle, handling of radioactive materials at all stages of their life cycle.

Государственный научный центр Российской Федерации – Федеральный медицинский биофизический центр имени А.И.Бурназяна ФМБА России: 75 лет на страже здоровья людей

The article presents the history of creation, formation and development of the State Scientific Center of the Russian Federation — Federal Medical Biophysical Center named after A.I. Burnazyan of the Federal Medical and Biological Agency of Russia (A.I. Burnazyan Federal Biophysical Center, the Center). The Institute of Biophysics of USSR Ministry of Health and Clinical Hospital № 6, predecessors of the Center, were engaged in the elimination of medical and sanitary consequences of Chernobyl Radiation Accident (1986). The main directions of activities of the A.I. Burnazian Federal Medical Biophysical Center — the flagship institution of Russian health care in the field of biophysics, radiation and nuclear medicine are considered. The perspectives of scientific activity of the Center related to solving actual problems of modern radiobiology, radiation safety and biomedical technologies are outlined. It is concluded that it is expedient to create the Disaster Medicine Service of the Federal Medical and Biomedical Agency of Russia.

The visualization of 3D nuclear radiation dose field

The nuclear energy is widely used as a new energy source due to the increasing depletion of fossil fuels. In the development of nuclear energy and technology, people are paying more and more attention to the issue of nuclear radiation protection. As a result, advanced computer technology has become a new way to solve nuclear radiation safety issues. This paper proposes to utilize CUDA-based ray-casting volume rendering to build an interactive nuclear radiation visualization system to solve the nuclear radiation safety problems, such as the judgment of radiation dose leakage and the planning of construction path. The system includes three modules, which are the overall dose rate distribution display of multiple power plants, the dose view of a specific equipment in power plants, and the dynamic evolution of nuclear radiation leakage. The analysis and user feedbacks of the experimental results show that this interactive visualization system can present the nuclear dose distribution of power plant in real time and from different granularities. This system utilizes the color mapping schema that as the dose density increases, the color changes from green to red, which is in line with human visual perception. Meanwhile, the dynamic radiation leakage scenario view is assistant to the design of nuclear radiation protection.

Ways to optimize the risk communication between specialists on radiation safety and population: recommendations on communication language

The article discusses the features inherent in the language of communication of specialists in radiation safety among themselves and with the public. Despite the confidence expressed by the population to specialists, their communication is difficult not only for organizational reasons, but also for their languages of communication. The population best understands the language not of the source of information on radiation safety issues (specialists), but of the transmitter of this information – journalists. It is necessary to take into account the difference in the tasks of specialists and journalists in conveying information to the population on the urgent problems of radiation safety, in particular, projects of the nuclear industry. It is shown that taking into account the peculiarities of the language characteristic of the population (or any of its groups) helps in a large degree to optimize information support for risk communication of the population on radiation safety issues. This is necessary for the development of an adequate attitude to the work of the nuclear industry. The article also considers the stages of risk- communication and the factors contributing to its optimization.

Development of the Photonuclear Method for Detection of Hidden (N; C) Concentrations with Registration of Induced (12N; 12B) Activities

An overview of the studies devoted to the development of the photonuclear method of external detection of hidden explosives and narcotic drugs using the registration of induced activities of the short-lived radioisotopes 12N and 12B is presented. The main aspects of this method are considered: the involved nuclear reactions; emission of γ-quanta, electrons, and positrons from irradiated objects upon (12N; 12B) decays; radiation safety problems; detectors for registration of (12N; 12B) activities at pulsed electron accelerators; and model descriptions of the attempts to implement the method.

Solution of neutron-transport multigroup equations system in subcritical systems

An iteration method has been implemented to solve a neutron transport equation in a multigroup diffusion approximation. A thermoelectric generator containing plutonium dioxide, used as a source of thermal and electric power in spacecraft, was studied. Neutron yield and multigroup diffusion approximation data was used to obtain a continuous and group distribution of neutron flux density spectra in a subcritical multiplying system. Numerical multigroup approaches were employed using BNAB-78, a system of group constants, and other available evaluated nuclear data libraries (ROSFOND, BROND, BNAB, EXFOR and ENDSF). The functions of neutron distribution in the zero iteration for the system of multigroup equations were obtained by approximating an extensive list of calculated and experimental data offered by the EXFOR and ENDSF nuclear data libraries. The required neutronic functionals were obtained by solving a neutron transport equation in a 28-group diffusion approximation. The calculated data was verified. The approach used is more efficient in terms of computational efforts (the values of the neutron flux density fractions converge in the third iteration). The implemented technique can be used in nuclear and radiation safety problems.

Представление архивной информации о ликвидации последствий радиационных аварий на интернет-портале

Purpose: To describe the historical experience of overcoming the consequences of radiation accidents for the environment, and also to enable the remote user independently obtain data on the radiation contamination of areas through the Internet-portal implemented within the Interdepartmental Information System on the issues of radiation safety and radiation problems.
 Material and methods: Specialists have collected a large volume of information obtained during expedition inspections of contaminated areas, starting in 1986 – the moment of the radiation accident at the Chernobyl NPP – and ending with 2015 (the year of the 30th anniversary of the accident), an array of paper official documents of different levels of hierarchy (departmental, interdepartmental, governmental). The Catalog of documents is composed in such a way that at each level one can get acquainted with the list of documents, with the meta-description of documents, with the original scanned source document (by reference given in the meta description).The scientific task of creating an information system, containing archival information, included the development of two groups of criteria for selecting information. All information was firstly analyzed by experts on two criteria: openness (a status that does not currently have restrictions on publication) and historical affiliation. The documents of this group include information from 1986 up to 2012. Then the criteria for assigning information to a particular group were developed. 
 Results: This work, for the first time, enables the remote user to obtain reliable data on radiation contamination independently. The user can know the years of the first and last inspection of the selected settlement, average density of cesium-137 contamination in the year of interest, as well as information on the number of samples taken in the year of interest. All data on the content of 137Cs obtained at different times are recalculated to the indicated single date (as of January 1 of each year), taking into account the correction for the radioactive decay of this radionuclide. In addition, the user can find out in the zone of which pollution category, approved by the Government List, is the locality indicated by the user. 
 Conclusion: Thus, the approach of presenting information on a specialized Internet-portal allows us to consider it as a tool for analyzing decisions taken. This approach allowed us to see the overall picture of efforts to overcome the consequences of a radiation accident. In the case of large scale radiation accidents and the adoption of many unconventional solutions at all levels of the hierarchy, this experience available to the remote user is crucial importance. The approach to the presentation of archival information on the overcome of the consequences of radiation accidents through Internet-portal showed the urgency of presenting the efforts of management, specialists and various services to overcome the consequences of such accidents with the help of a systematic array of historical documents. The users’ appeals to the Internet-portal through page of Rosgydromet are recorded in the Journal of events. It tells about the expediency of this work. Address of electronic archive is following: http://rb.mchs.gov.ru/rosgidromet/Archive. The link of reference services is following: http://rb.mchs.gov.ru/rosgidromet/rg_spravochnie_uslugi.

Photoneutrons for Radiation Therapy and Radionuclide Production

The possibility of organizing neutron therapy with a photoneutron beam produced by the electron accelerator target, and ensuring the required dose at the tumor at a reasonable exposure time and with minimal impact on patients investigated. Generation of neutrons from the target of electron accelerator takes place in two stages: e- ® γ ® n, and in the selected electron energy range of 20-100 MeV, the bremsstrahlung gamma radiation in many times (~ 3 orders of magnitude) offers more than “useful” neutron yield. This raises the problem of the selective control of the “harmful” for radiotherapy secondary gamma radiation while providing the minimum attenuation of the neutron flux in the output beam. In order to solve the general problem of the formation of a neutron beam with necessary spectral characteristics having sufficient intensity, there has been resolved a number of computational tasks of the selection of the optimal configuration of the output beam unit and its composition. The matter of high importance is to minimize additional irradiation of the patient from the bremsstrahlung (generated by electrons) and secondary gamma radiation (generated by neutrons) from the accelerator target as well as from output unit’s materials. On the other hand, at a generation stage e- ® γ the bremsstrahlung beam could be applied for effective radionuclide production by reactions (γ,n) and (γ,p) due to high leak intensity ~ 1.3·1017 photon/s. By the Mo100(γ,n)99Mo reaction the main diagnostic nuclide 99Tc could be produced sufficiently for the clinical needs. The resulting configuration of the output unit provides the required beam quality for the neutron capture therapy (NCT), which commonly assumed to be the only competitive technology of neutron therapy on the background of the massive invasion of proton therapy and other highly selective techniques that ultimately damage the target sparing the surrounding tissues and organs. For the accessible accelerator (average current 4 mA and electron energy 35 MeV) the flux density of epithermal photoneutrons (they required for NCT) in the beam at the output is of the order of magnitude or more higher than the typical yield from existing and planned reactors' beams. The proposed scheme of generation and extraction of photoneutrons for NCT has a number of strong advantages over traditional techniques: a) the applying of electron accelerators for neutron production is much safer and cheaper than conventional reactor beams in use; b) accelerator with the target, the beam output unit with the necessary equipment can be placed on the territory of the clinic without any problems of radiation safety; c) the proposed target – liquid gallium, which also serves as a cooler, is an “environmentally friendly” material due to low activation which rapidly (in ~ 4 days) falls to the background level.

ПСИХОЛОГІЧНІ ОСОБЛИВОСТІ СПРИЙНЯТТЯ РАДІАЦІЙНОГО РИЗИКУ

В статті проведено аналітичний огляд психологічних властивостей радіаційного впливу, перераховані фактори посилюючі неадекватне сприйняття радіаційної загрози. Визначенні суб’єктивні особливості сприйняття радіаційного ризику та вивчено місце ризику радіаційної загрози серед інших вітальних небезпек у віддалений період після аварії на ЧАЕС. Виявлено високий відсоток осіб з гіпертрофованим сприйняттям радіаційної загрози серед УЛНА та евакуйованих із зони відчуження, що свідчить про актуальність для них таких стресових подій в їхньому житті, як катастрофа на ЧАЕС та евакуація навіть через 31 рік після радіаційного інциденту. Вперше проведено оцінку сприйняття радіаційної загрози учасниками АТО.  &nbsp

Modernization of radiation detectors thickness gauge

Currently, there is a tendency in the industry by refusing isotopic radiation sources in favor of the X-ray machines. This is due to several factors, main among them radiation safety and maintenance problems, movement and disposal of gamma-ray sources. Compared to the gamma ray-source these devices have a number of disadvantages. The spectral energy distribution and therefore change in the spectrum as the radiation passes through the controlled material. Instability of radiation compared with gamma sources. All this complicates the use of X-ray sources for the materials thickness measurement with different chemical compositions.

Risk-communication issues in radiation safety: Mass consciousness about radiation and nuclear industry based on the results of a sociological research in St. Petersburg, the Leningrad region and the Murmansk region

The study is devoted to a mass reflection of the problems of radiation safety and the functioning of the nuclear industry in the modern Russia. The analysis of the population’s awareness, peculiarities of the perception of radiation risks and the tendencies in the formation of a public assessment of large nuclear projects have been carried out. Materials and Methods: The data were collected during mass surveys of representative samples of the population of two regions located in the Northwest of the Russian Federation: 1) St. Petersburg and the Leningrad region. (2369 respondents, November 2016) and 2) the Murmansk region. (802 respondents May 2017). The results show that radiation is perceived by society as one of the most significant threats to life and health. However, the public concern does not give rise to a mass interest in the thematic information. The real level of knowledge of the population is clearly insufficient for literate actions in an extreme situation, or for the safe behavior in the everyday life. Public opinion is formed mainly on the basis of mass media reports. At the same time, it has been established that groups of the population well informed in the radiation field are much more likely, than others, to support the nuclear industry, including the least popular projects. Conclusion: Therefore, active informing of the population on the issues of the operation of nuclear facilities, the presence of radioactive contamination sites and other sources of danger, etc. objectively contribute to the growth of the industry’s reputation. It is advisable to use social technologies to overcome the cognitive and practical passivity of the Russian citizens and to form the population’s radiation culture.

Activation and shutdown dose-rate analyses for the EAST NBI test facility

An analysis of the neutron activation and shutdown dose rates was performed for the EAST high-power deuterium neutral beam injector test facility (EAST NBITF) by using the multiparticle transport code FLUKA 2011.2. Also, the neutron and neutron-induced gamma spectra of the facility’s vacuum vessel were evaluated. The results identified the major radionuclides 99Mo, 65Ni, 58Co, 56Mn, and 51Cr for the vacuum vessel and the primary nuclide 64Cu for both the ion dump and the calorimeter. The simulated results indicated that, when the EAST NBITF operates within the design parameters of deuterium energy 80 keV, current 50 A, and pulse 100 s, the neutron intensity will achieve 1011 n/s with no radiation safety problems after the EAST NBITF shuts down.

The use of fly ash the thermal power plants in the construction

The problems of ecological and radiation safety of the construction of man-made waste like fly ash thermal power plants were researched. The chemical composition of TPPs ashes of Primorsky Territory was studied, defined their specific effective activity of natural radionuclides. The most modern research methods were used - differential thermal analysis, thermogravimetry, X-ray analysis. It was revealed that the ash of the Primorskaya TPP and Partizanskaya TPP has exceed the permissible parameters of radioactivity, so not suitable for use in construction. Ashes of Vladivostok TPP-2 and Artem TPP of Primorsky Region on parameters radioactivity and chemical composition have suitable for use as a filler in the concrete.

Проблеми хімічної та радіаційної безпеки України (за матеріалами наукової доповіді на засіданні Президії НАН України 29 квітня 2015 р.)

Проблеми хімічної та радіаційної безпеки України (за матеріалами наукової доповіді на засіданні Президії НАН України 29 квітня 2015 р.)

Characteristics of radiation safety for synchrotron radiation and X-ray free electron laser facilities

Radiation safety problems are discussed for typical electron accelerators, synchrotron radiation (SR) facilities and X-ray free electron laser (XFEL) facilities. The radiation sources at the beamline of the facilities are SR, including XFEL, gas bremsstrahlung and high-energy gamma ray and photo-neutrons due to electron beam loss. The radiation safety problems for each source are compared by using 8 GeV class SR and XFEL facilities as an example.