Hasil untuk "Radioactivity and radioactive substances"

Jeremy Whitlock

This paper presents basic principles of Safeguards by Design (SBD), whereby the International Atomic Energy Agency (IAEA) provides guidance to State and regional safeguards authorities, designers, equipment providers and prospective purchasers on the importance of taking international safeguards into account when designing or modifying a nuclear facility or process.

A. V. Gromov, A. M. Biblin, K. A. Sednev et al.

The study presents summary, analysis, and hygienic assessment of data on the radiation accidents related to violations of the rules of gathering and recycling of ferrous and non-ferrous metal scrap within the Russian, based on data from the Radiation Accidents and Incidents Database of the Information and Analytical Center of Rospotrebnadzor on Radiation Safety. The aim of the study was to analyze information on radiation accidents associated with violations in the collection and handling of scrap metal occurring in the Russian Federation over period from 2010 to 2023. A total of 971 radiation accidents related to improper handling of scrap metal were recorded across 41 regions in Russia during the study period. The largest number of the accidents occurred in Vologda (206), Sverdlovsk (178), Khabarovsk (150), Saint Petersburg (116), and Orenburg (52) regions. A negative trend in the accident frequency was observed, with an average annual decline rate of 12%, indicating a steady decrease in occurrences over the last 14 years. The primary sources of radioactive contamination in scrap metal included fragments of various radiation-related equipment, pipes, and technological equipment from the oil and gas industry contaminated with natural radionuclides during use (primarily 226Ra and its salts), as well as devices containing permanent luminescent substances based on 226Ra salts. The identified sources were most commonly associated with the radionuclides 226Ra (63%), 137Cs (12%), 60Co (9%), 238U (9%), with occasional cases involving 241Am, 232Th, and 90Sr. In 66% of cases, the ambient gamma dose equivalent rate on the source surface exceeded 1 μSv/h; in 27% it exceeded 10 μSv/h, in 7% it exceeded 100 μSv/h, and in five cases were in range from 1 to 8.8 mSv/h. It was found that sources of ionizing radiation posing potential health risks to the public have been detected throughout the study period. In 14 cases, radioactive contamination was identified in scrap, indicating accidents of melting down radiation sources without investigation into the circumstances or assessment of potential adverse effects. In most (64%) of the registered radiation accidents, the batches of scrap metal were accompanied by radiation control certificates from accredited laboratories, confirming compliance with sanitary standards and regulations. The analysis of radiation accidents related to violations in the collection and handling of scrap metal revealed that the current domestic system for ensuring radiation safety during the procurement and sale of scrap metal remains effective and relevant. Recommendations for improving emergency response during investigations of such radiation accidents have been provided to the Rospotrebnadzor organizations.

Claudia Morales, Lourdes Torres, Fabricio Brollo

Guided tours of the RA-6 nuclear research reactor provide a unique opportunity to bring students, teachers, researchers, and the general public closer to the reality of this technology. They aim to promote a deeper understanding of its operation, facilities, applications, and safety protocols, with the goal of dispelling misconceptions, overcoming myths, and alleviating associated fears. Year after year, from 2018, excluding the pandemic period, the number of visitors has increased, reaching over 3000 individuals in 2023 from Argentina and various regions of Latin America and the world. This increase has had a positive impact on both the community and public perception regarding nuclear technology.

Josemary A. C. Gonçalves, Elisabeth S. R. Somessari, Samir L. Somessari et al.

The growing interest in low-dose (< 100 Gy) radiation processing applications has raised concerns about accurately measuring the absorbed dose in irradiated materials. Depending on the irradiator design, the transit time due to the radioactive source movement (or the product itself) until the stable irradiation position might affect the predicted absorbed dose. This work aims to evaluate the transit dose in a 60Co Gammacell 220-Nordion irradiator, which has radioactive sources settled at the bottom of a lead shielding. When the facility is on, the product and the dosimeter are mechanically guided down to the irradiation position, and hereafter the selected exposure time starts to be counted. At the end of irradiation, both product and dosimeter rise to the initial position enabling them to be gathered by the operator. The product is continuously irradiated at different dose rates during its fall and rise movement, preventing the transit dose from being obtained straightforward. The experimental approach adopted is to assess the transit time, and thus the transit dose, using an online diode-based dosimetry system previously calibrated against reference standard alanine dosimeters. The agreement between the transit doses attained with the diode (0.41 ± 0.02) Gy and alanine ((0.38 ± 0.01) Gy validates the method herein proposed.

Elaine Aparecida Rodrigues, Afonso Rodrigues Aquino, Amanda Rodrigues de Carvalho

If in the 19th century scientific knowledge moved from a generalist perspective to a growing specialization, in recent decades, problems that transcend disciplinary and political boundaries have required solutions based on interdisciplinary research and global actions, which led to the establishment of the Sustainable Development Goals (SDGs). Viewing from the latter perspective, the study of ecosystem services has converged on a fast-growing, transdisciplinary area of knowledge, at the same time that the advances in the nuclear field have enabled applications in industry, health, agriculture and the environment. Considering the development of these two areas of knowledge, the objective of this study is to evaluate the correlation between Ecosystem Services (ES) and Nuclear Science and Technology (NST), by means of category building and content analysis applied to articles compiled from Web of Science. From 1980 to June 2020, 27,301 records (articles and reviews) were listed for the term “Ecosystem Service*”. When refining the result with the application of descriptors related to the nuclear field, correspondences were found for “Uranium”=14; “Nuclear Power”=6; “Nuclear Energy”=3; “Nuclear Technology*”=1; “Nuclear Fuel*”=1; “Nuclear Material*”=1; “Radiation”=7; “Isotope*”=188, totalizing 221 correspondences. On the other hand, 9,949 records were obtained for the same time interval, when using the descriptors for the nuclear field, plus the terms “Nature” or “Ecosystem*” or “Environment”. Despite attesting that NST truly converges on ES, this correlation needs to be made more explicit in ES studies, in order to expand the perspectives for the conservation, preservation and recovery of the ecosystem services and their contribution to human well-being.

A. M. Biblin, A. A. Davydov, N. M. Vishnyakova et al.

In the event of radiation accidents and incidents related to a possible threat to public health, one of the tools for forming health-saving behavior of the population, ensuring the social acceptability of protective measures and reducing social tension is crisis communication. Nuclear and radiation emergencies associated with the potential for radioactive contamination of large areas or the impact on the population can become the basis for the emergence of resonant information events. Properly organized crisis communication with the population in such situations is one of the necessary conditions for the effectiveness of emergency response. The article analyzes the impact on crisis risk communication of some features of nuclear and radiation events that have occurred in recent years. These events have had a significant impact on the possibility or impossibility of following the general principles of crisis communication, and provides examples of recommendations for adjusting information work if it is impossible to strictly follow the general principles of crisis communication in real circumstances. The study made it possible to identify the following features of the development of specific crisis situations that influenced the course of crisis communication and created a number of difficulties: 1) the latent nature of the early phase of the accident; 2) absence or deliberate concealment of information about a radiation accident; 3) the transboundary nature of the accident; 4) hidden (secret) nature of information about the accident; 5) an increase in the level of radiation anxiety among the population of the territories not affected by the accident; 6) the rapid formation and spread of myths; 7) projecting artistic images on a real accident. The analysis of the influence of the features of radiation accidents and incidents on the crisis communication allowed us to come to the following conclusions: 1) crisis communication is an important component of emergency response, affecting both the psychoemotional state of the population and the effectiveness of emergency measures related to the actions or inaction of the population; 2) the development of means of information interaction and methods of dissemination and consumption of information requires a revision of traditional methods of information work with the population; 3) the information should be timely, objective, consistent and understandable both for the public and for non-specialists in the field of radiation hygiene responsible for making management decisions; 4) information should not be presented in the form of short messages without explanations; 5) contradictory aggressive information received by the population from different sources may cause distrust of official sources of information; 6) if you do not provide up-to-date and objective information about the accident, the public’s trust is very easy to lose and very difficult to restore.

Claudio Henrique dos Santos Grecco, Silas Cordeiro Augusto, Jaqueline Tavares Viana de Souza et al.

The explicit and tacit knowledge of workers constitute as valuable resources, as they enable organizations to perform their functions successfully. Such knowledge is derived from the qualification and experience of workers. On the other side, there are factors that favor the loss of this knowledge in organizations, as for example, the natural aging of workers and consequently the retirement and staff turnover. Because of these reasons, it becomes important for any organization to seek the preservation of its explicit and tacit knowledge. The Knowledge Management seeks to assist in the tasks of identification, organization, preservation and transmission of such knowledge. At the Nuclear Engineering Institute, three systems were developed and implemented to help in the Knowledge Management area: CarpeDIEN, a repository of research data based on the DSpace software; the “Nuclear Energy in Magazines”, a peer-reviewed academic journals management system based on the Open Journal Systems software; and WikiIEN, a wiki based on the MediaWiki software. Each of these systems presents a different proposal and workflow. The objective of this paper is to present the characteristics of each system, a method to compare them based on criteria presented in the literature and to point their weaknesses. The results showed that the method is a proactive tool to provide a basis for choosing the most appropriate system for a given need in an organization.

João Domingos Talon, Alberto Teixeira Neto, Thomaz Jacintho Lopes et al.

Neste trabalho, o núcleo de um reator modular de pequeno porte (SMR) hipotético do tipo PWR, com um enriquecimento do combustível de 20% e potência de 50 MWe (150MWt)[1], foi simulado na condição de criticalidade. A 300cm do vaso de pressão do SMR foi medida a dose efetiva de 1,33E+9mSv, que mostrou a necessidade de calcular e instalar uma blindagem multilaminada no contexto do plano de proteção radiológica da instalação nuclear para fins de licenciamento e cumprimento das diretrizes pertinentes. Os dados disponíveis foram utilizados no dimensionamento do projeto básico do serviço de proteção radiológica da instalação, além da possibilidade de serem aplicados na elaboração do respectivo PSAR[2]. [1] MWe: megawatt elétrico e MWt: megawatt térmico. [2] PSAR: Preliminary Safety Analysis Report.

Ezequiel da Silva, Lucas Rodrigues Santos, Ladyjane Pereira Fontes Assemany et al.

Introduction: The discovery of ionizing radiation and its application in medicine was an important advance for society due to the various possibilities of use for treatment and diagnosis of diseases. On the other hand, the knowledge about the damages caused by the biological effects of the ionizing radiation, requires a continuous improvement of the quality control in diagnostic radiology. Radiation detectors are equipment used to measure the levels of radiation emitted by sources, be they natural or artificial. Among the most commonly used detectors are ionization chambers (IC). During transport for clinical routine use, sudden changes in temperature and humidity may affect the behavior of these detectors at the time of measurement. For the equipment to recompose its stability, it is necessary a time that is often incompatible with the free time available for the tests. The objective of this work was to evaluate the performance of an ionization chamber used in radioprotection measurements in diagnostic radiology, considering the climatic variations in the different regions of Brazil[1]. For that, a system of air conditioning was developed to simulate the environmental situations found for the parameters of temperature and humidity at the moment of the clinical measurements, making possible to estimate the influence of these factors in the obtained values. Methods: Before submitting the IC to the proposed climatic tests, the dosimetric system composed of an ionization chamber for radioprotection (Radcal®, 10x15 - 1800) and electrometer (Radcal® 9015) was calibrated in the instrument calibration laboratory of the Instituto de Pesquisas Energéticas e Nucleares (LCI-IPEN), in the ISO N series radiation qualities[2,3]. In order to evaluate the behavior of the detector in different environmental conditions, a system of air conditioning was constructed, which allows the control of humidity and temperature in an acrylic box with dimensions appropriate to the test, and a control source of 90Sr + 90Y [PTW® , model 8921, 33MBq (1994)] for the irradiation of IC. The IC was then positioned within the acclimatization chamber for 15 minutes for stabilization according to the manufacturer's manual. A series of measurements was made with the source of the check to analyze the behavior of the CI with the typical environmental conditions of the city of Manaus, capital of Amazonas state that is located in the north of Brazil. Conclusions: Preliminary results indicate an increase in the accumulated dose values obtained with the ionization chamber due to increase in temperature. The humidity parameter interfered in the background value measured by the ionization chamber and after the test, the ionization chamber showed a significant current leakage. Determining the influence of environmental factors is not an easy task, but it is fundamental to the reliability of measurement and optimization of quality control. The methodology proposed in this work pointed to a repeatable character, allowing the simulation of environmental tests for the parameters of humidity and temperature of several models of ionization chambers.

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Shirley da Conceição Magalhães, Suede Martins da Silva, João Carlos Leocadio et al.

Uma análise de características e propriedades das rochas, após a perfuração de um poço de petróleo, pode ser executada utilizando-se perfilagem elétrica, de indução, sônica e radioativa. A perfilagem radioativa pode ser do tipo gama-natural, gama-gama e neutrônica, sendo que nesta utiliza-se fontes radioativas de 241Am-Be até 851 GBq e 252Cf até 4,1 GBq. Os IOEs da área de perfilagem de poços de petróleo são monitorados duplamente, tanto para radiação de fótons como para nêutrons. No Brasil, apesar de existir 10 instalações de perfilagem de poços de petróleo com 40 SPRs e 3 laboratórios de dosimetria de nêutrons, os dados sobre a monitoração individual de nêutrons de IOE não são devidamente apresentados sistematicamente. Este trabalho apresenta um panorama da área de perfilagem de poços de petróleo, enfocando os tipos de dosímetros, o número de IOEs e resultados de monitoração individual. Na pesquisa bibliográfica foram utilizados dados publicados independente do período e os publicados no UNSCEAR. Os resultados apresentam detalhes dos tipos de dosímetros de nêutrons mais utilizados, bem como, dados relativos à evolução do número de IOEs com monitoração gama e de nêutrons. Os dados analisados mostram que a perfilagem de poços de petróleo tem tido um aumento no número de IOEs com monitoração individual para nêutrons ao longo dos anos, e a dose efetiva média anual vem diminuindo progressivamente. Conclui-se que para se obter uma visão mais detalhada sobre monitoração individual para nêutron, em perfilagem de poços de petróleo, os dados devem ser publicados de maneira adequada e constante.

Pedro Argôlo Piedade

In Stereotactic radiosurgery (SRS), indexes are used to compare plans, comparing treatment techniques and evaluate clinical complications. However, they have some limitations and dependencies that need to be well known. Therefore, the analysis using indices is better suited for comparison of plans for the same patient (lesion). The evaluation of stereotactic plans must be undertaken with great care and criteria because there is a huge amount of information between different dose distributions of treatment plans. The objectives are to show some tools for planning analysis in SRS their limitations, some indexes descriptive review in the literature that seek to quantify the three properties mentioned and discuss the concepts involved in SRS dose prescription.

Wagner Souza Pereira, Alphonse Kelecom, Rodney Santos et al.

During its operation, the Nuclear Fuel Factory of the Nuclear Industries of Brazil (FCN/INB) may generate and disseminate particulate material. Therefor, aiming occupational control, a system of air exhaustion is installed equipped with a system of automatic detection of release of radionuclides into the environment. The present work aims to evaluate the radionuclides released by FCN, in terms of total release and activity concentration (AC). Along 2016, the amount of 4.14∙106 Bq was released, which means a mean of 3.45∙105 Bq.month-1. The largest mean for AC was 4.03 mBq∙m-3. The release data was almost an order of magnitude lower than the annual release limit established by the regulatory agency, fixed at 1.2∙107 Bq.y-1, proving the adequacy of the atmospheric effluents to the licensing requirements. The largest magnitudes of the two variables (AC and release) were observed in August while the smallest ones, in January.

S. S. Aleksanin, V. Yu. Rybnikov, K. K. Rogalev et al.

This paper presents the experience and features of the organization and provision of specialized and hightech medical care to victims of the Chernobyl accident in the framework of the activities of the Union State in the Nikiforov Russian Center of Emergency and Radiation Medicine EMERCOM of Russia. It reveals the features of the morbidity, disability and mortality of the injured in the accident at the Chernobyl nuclear power plant. The paper presents the data on the types and amount of medical assistance provided to victims of the Chernobyl accident for the period from 2007 to 2018 as well as the features of the organization of rendering specialized, including hi-tech, medical assistance and medical rehabilitation to participants of liquidation of consequences of the Chernobyl accident and inhabitants of the radioactively contaminated territories.

I. G. Shatsky

The use of the effective dose (the concept of which was developed for radiation protection of workers and public) and the nominal risk coefficients, averaged by sex and age, to assess the radiation risks of medical exposure has some significant limitations. Age and sex distribution of the staff and the entire population may be quite different from the sex and age distribution of patients undergoing medical exposure. Moreover, the structure of the age and sex of patients may be different for various medical examinations. There are simplified methods for evaluating individual risk for patients undergoing medical exposure. The methods are based on the effective dose evaluation and those take in to account age and gender. A more accurate assessment of lifetime risk of delayed stochastic effects for health of the patient is achieved by using the organ doses and the age and gender risk factors. The aim of this work was evaluation of the lifetime risk of long-term stochastic health effects for different gender and age groups of children undergoing various radiographic investigations by using organ doses and the age and gender risk factors, and subsequent classification in accordance with generally accepted international risk scale. Data from surveys of33 X-ray units in 29 specialized pediatric health care organizations in Russia were used in the work. Organ doses and patient’s effective doses were calculated on the basis of the defined for each x-ray machine typical modes for the 12 radiographic procedures (X-ray exam of the skull, chest, cervical spine, thoracic spine, lumbar spine–all in two projections – of the abdomen and pelvis – both in one projection)using a computer program PCXMC., Radiation risks for selected studies were estimated using the obtained organ doses and the age and gender risk factors calculated for the Russian population. The radiation risks were classified according to the international scale of the risks. It was found that the risk dependence on the sex and age is significant. For a number of examinations ,the gender dependence prevail; higher risks are intrinsic to female. For others examinations, a strong dependence on the age was revealed, such as an increase of the risk for the middle age group of children (10-14 years) compared to the younger and older groups.

I. K. Romanovich, I. P. Stamat, N. I. Sanzharova et al.

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.

A. N. Barkovskiy

An article contains substantiation of advisability of rejection of subtraction of background dosimeters indication values from the measured values of individual doses of occupational exposure of A-group personnel in the process of carrying out of individual dosimetry control of medical organizations stuff which was implemented in the Methodical Guideline 2.6.1.3015-12. It is shown that mentioned procedure is firstly incorrect when we deal with low doses, when the impact of natural exposure could be really considerable and secondary senseless when we deal with dose values close to the dose limit value for A-group personnel when the impact of natural exposure is much lower then the error of measurements. It is suggested to carry out the account of the impact of natural exposure into personnel average doses basing on the analysis of statistical distributions of personnel individual doses and on indications of background dosimeters. It is suggested to add the information about indications of background dosimeters into the Base of Federal Statistical Supervision № 1-DOS as it is prescribed in the Methodical Guideline 2.6.1.3015-12. This article is the respond to the article of A.I. Grigoriev published in the present issue of Journal, in which the author contests the reasonableness of this provision.

Claudia Lucia de Pinho Mauricio, Herica Luiza Ramos da Silva, Claudio Ribeiro da Silva

Brazil, a continental country, with actually more than 150,000 workers under individual monitoring for ionizing radiation, has implemented in 1987 a centralized system for storage of external occupational dose. This database has been improved over the years and is now a web-based information system called Brazilian External Occupational Dose Management Database System - GDOSE. This paper presents an overview of the Brazilian external occupational dose over the years. The estimated annual average effective dose shows a decrease from 2.4 mSv in 1987 to about 0.6 mSv, with a remarkable reduction from 1987 to 1990. Analyzing by type of controlled practice, one sees that the medical radiology is the area with the largest number of users of individual monitors (60%); followed by educational practices (9%) and industrial radiography (8%). Additionally to photon whole body monitoring; neutron monitors are used in maintenance (36%), reactor (29%) and education (27%). Extremity monitors are mainly used in education (27%), nuclear medicine (22%) and medical radiology (19%). In terms of collective dose, the highest value is also found in medical radiology, but the highest average dose value is received by interventional radiology IOE. Nuclear medicine, radiotherapy and research practices present average annual effective dose higher than 1 mSv. However, some dose values higher than 500 mSv registered in the data base give false information. They are not realistic. This should be better analyzed in the future to improve the analysis of the trends of external occupational dose in Brazil.

A. T. Gubin, V. A. Sakovich

A mathematical model for radiogenic increasing of mortality was proposed, taking into account spontaneous background damages of the genetic material, that always occur in cells due to the influence of non-radiation internal and environmental factors. The model is based on the representation of indistinguishability between radiogenic andspontaneous cancers and on the postulates of the Kellerer-Rossi dual action theory. It was proposed that duringformation of premalignant damages dual interactions occur both between primary radiation damages, and betweenradiation and spontaneous primary damages (hybrid interactions). The role of the latter is particularly important at low levels exposure that corresponds to a linear dependence of cancer incidence on dose. Their significance is indicated by the following factor: at the adopted value of the nominal (radiation) risk factor (0,05 Sv-1) and cancer mortality share among the population (0,15–0,2), the contribution of non-radiative carcinogenic factors for the total life is equivalent to radiation dose of 3–4 Sv or radiation at a constant dose rate of 40–50 mSv / year.The model assumes formation in DNA of both spaced apart (single) damages with high probability of recovery, and nearby (double) damages, which are more likely to interact, entering into the permanent state. Permanent damages being formed in certain portions of DNA can be inherited to daughter cells as premalignant defects. The relative role of spontaneous primary damages is greater the more single damages are formed as compared to double ones within the area of potential interaction.It was shown within this model that the presence of background cancer mortality for initial and finite population in the used by ICRP expression for interpopulation risk transfer has logical and biophysical justifications. Accounting of spontaneous primary damages and hybrid interactions enhances the capabilities for development of radiation risk models.

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