Hasil untuk "Radioactivity and radioactive substances"

Santiago Gregorio Acuña, Marcelo Oscár Gim´enez, Mariela Grinberg et al.

This study presents a quantitative system dynamics model developed to understand and enhance nuclear safety culture and operational performance in nuclear power plants. The model employs causal loop diagrams and stock-and-flow diagrams, created using Vensim PLE+ software, to capture and simulate the complex interactions that define safety culture dynamics. Recognizing the fundamental role of organizational culture in maintaining nuclear safety, the model incorporates key elements such as leadership, risk perception, continuous improvement, internal communication, and the commitment of management and personnel. Through an extensive literature review and expert consultations, the research integrates critical variables into the model, grounded in frameworks from the International Atomic Energy Agency (IAEA) and the World Association of Nuclear Operators (WANO). Simulating a decade of safety culture management dynamics, the model reveals the impact of management strategies, demonstrating the effectiveness of continuous improvement initiatives and proactive leadership in enhancing safety outcomes. Stress tests conducted under extreme scenarios validated the model's robustness, reaffirming its applicability in safeguarding safety culture under intensified production pressures. The findings provide actionable insights for nuclear safety professionals and decision-makers, promoting environments that support safety-focused practices. This model serves as a comprehensive tool to advance safety culture in nuclear operations, offering valuable perspectives for both theoretical discourse and practical nuclear safety management.

I. K. Romanovich, A. B. Bazyukin, A. N. Barkovsk et al.

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.

L. V. Repin, R. R. Akhmatdinov, A. M. Biblin et al.

This paper describes the preconditions of creation and the process of development of the Automated System for Radiation Risk Analysis. Three main objectives for the development of an automated system for radiation risk analysis were identified: creation of a tool for the development and scientific justification of hygienic standards and other protective quantities in the field of ionizing radiation application; practical implementation of the principles of justification and optimization in radiation protection on the basis of monetary assessment of radiation health risks; and comparative analysis of risks of different nature on the basis of comparable indicators of population health. The Russian software platform 1C: Enterprise was chosen as the development platform for the Automatized System for Radiation Risk Analysis. The choice of this platform was related to simplification of integration with other computer systems being developed at the Research Institute of Radiation Hygiene after Prof. P.V. Ramzaev, such as the Automated System for Radiation Exposure Control of Rospotrebnadzor. Before the practical development of the system in accordance with the terms of reference, the main parameters in view of its interaction with the user were determined: arrangement of the user interface elements, main input parameters, primary calculated indicators and output calculation results, etc. The estimation of annual increase in the probability of radiation-induced malignant neoplasms depending on the organ dose, sex and age of the exposed person and other parameters according to the models of the UN Scientific Committee on the Effects of Atomic Radiation, the U.S. Environmental Protection Agency and Publications 103 and 152 of the International Commission on Radiological Protection was implemented in the system. The capabilities of the system include calculation of a number of modern lifetime radiation risk indicators used for risk characterization in various scientific publications over the last 35 years, including calculation of population risks based on national medical and demographic data of several dozen states published over the last 50 years.

L. A. Ferrari, J. M. S. Ayoub, R. L. A. Tavares et al.

This paper aims to discuss the convenience and feasibility of increasing the nuclear energy participation on the Brazilian energy mix, amid a national context of climate change, scarcity of natural resources necessary to baseload energy generation, particularly hydropower, discussions on a possible restart and expansion of Brazilian nuclear program, whilst the population still suffers socioeconomic impacts resulting from COVID-19 pandemic as well as the pre-pandemic economic crisis. The work proposes four analysis axes: environmental factors, economic, safety/legislation and technological aspects, and through bibliographic research in scientific articles published in journals, theses, dissertations, laws, regulations and international recommendations, it was possible, as a result of the research, to draw an optimistic overview of a possible future expansion of the Brazilian nuclear program, considering the advantages and challenges of using the nuclear alternative when compared to other energy sources.

A. N. Barkovsky

The current system of regulatory requirements in the Russian Federation for the handling of products containing or being man-made sources of ionizing radiation does not sufficiently take into account differences in the radiation hazard of various types of radiation equipment. For radiation objects of different categories of potential radiation hazard, it is largely the same. In all cases, it is required to issue a sanitary and epidemiological conclusion on the compliance of working conditions with ionizing radiation sources with sanitary rules and licenses, which in this case practically duplicate each other. As one of the possible ways to ensure greater differentiation of regulatory requirements taking into account the real danger of various sources, the formation of a three-level system of sanitary and epidemiological regulation of the use of technogenic sources of ionizing radiation is proposed. The first level is radiation equipment products, the radiation doses of people due to the use of which cannot exceed the established hygienic standards for the population under any conditions of the use for which these products are designed. Their handling is exempt from regulatory control and should be carried out as with products that do not pose a radiation hazard. The second level is radiation technology products that do not pose a serious potential radiation hazard to people, but require certain regulation of their handling to ensure a socially acceptable level of radiation safety. Handling of them is allowed in the presence of sanitary and epidemiological conclusion, and a simplified radiation monitoring system may be allowed. The third level is the products of radiation technology that pose a significant potential radiation hazard to humans. A serious harm to human health is possible in case of violations of the rules for handling such products and in the event of a radiation accident. Handling them is allowed if there is a sanitary and epi- demiological conclusion and a license. Such an approach, while maintaining the achieved level of radiation safety, will significantly simplify the regulatory system and eliminate unreasonable obstacles to the expanded use of radiation technology. It is also necessary to consider the possibility of developing special standards to ensure sanitary and epidemiological requirements of the use of mobile and mobile medical diagnostics using sources of ionizing radiation. The absence of such standards hinders the implementation of modern methods of X-ray diagnostics.

D. A. Zaredinov, M. V. Li

The scientific article is devoted to the actual problem of modern medicine – the exposure of the public during multislice spiral computed tomography in the Republic of Uzbekistan. For the period 2017-2020 the number of computed tomography procedures increased from 175000 to 375000 (by a factor of 2), there was an increase in the collective dose from computed tomography from 987,5 to 2482,6 man-Sv (2.5 times). During the study the patient effective doses were calculated and the risks were assessed. The research work was carried out in medical institutions on CT units from different vendors. The examination protocols of 1126 adult patients were analyzed. The patient effective doses during MSCT of various anatomical regions were calculated from the DLP value and their comparative assessment was carried out. The radiation risk assessment was carried out on the basis of the effective dose using the nominal ICRP risk coefficients adjusted for age-related radiosensitivity. According to the results of the studies, it was found that when examining the head area, the effective doses of patients ranged from 1.3 ± 0.3 to 1.9 ± 0.2 mSv, the neck area – from 1.3 ± 0.3 to 2.4 ±0.3 mSv, the chest area – from 5.3 ± 0.7 to 6.6 ± 1,9 mSv, abdomen – from 7.0 ± 1.0 to 8.8 ± 1.6 mSv, small pelvis – from 7.8 ± 1.0 to 10.8 ± 2.5 mSv. The lifetime risk of long-term stochastic effects for the health of a patient from 18 to 65 years old was in the range of 10-4 – 10-3. The results of the study showed that the effective doses differ significantly from each other depending on the anatomical area of study of the patients. A person receives the highest doses of radiation when examining the pelvic and abdominal area, and smaller ones when examining the head area. The difference in the values of effective doses in the study of the same anatomical parts of the human body mainly depended on the weight of the patients, the length of the studied anatomical area, the model of the computer tomograph.

Sandra Regina Damatto

The water parks located in the cities of Cambuquira, Caxambu, Conceição do Rio Verde, Lambari and Marimbeiro are part of the Water Circuit of Minas Gerais and have their mineral waters regularly consumed by the local population and tourists motivated by the medicinal use of these waters, characterized as mineral waters. Therefore, the objective of this work was to determine the inorganic chemical composition of the mineral water from these parks, analysing the elements Ag, As, Ba, Ca, Cd, Co, Cr, Cu, Fe, K. Mn, Ni, Pb, Se, Ti, V and Zn using the energy dispersive X-ray fluorescence – EDXRF. Despite the proximity to one another, each park has different chemical elements and concentrations. The elements presenting the highest concentrations were the major elements Ca, Fe, K and Mn. However, among the five water parks studied, the Water Park of Caxambu presented the highest concentrations for all the determined elements.

Maysa Costa Castro, Natália Fiorini da Silva, Linda Viola Ehlin Caldas

Computed tomography (CT) diagnostic exams are responsible for the highest dose values to the patients. Therefore, the radiation doses in this procedure must be accurate. For the dosimetry of CT beams, the radiation detector is usually a pencil-type ionization chamber. This type of dosimeter presents a uniform response to the incident radiation beam from all angles, which makes it suitable for such equipment since the X-ray tube executes a circular movement around the table during irradiation. However, there is no primary standard system for this kind of radiation beam yet. In order to search for a CT primary standard, an extrapolation chamber built at the Calibration Laboratory (LCI) of the Instituto de Pesquisas Energéticas e Nucleares (IPEN) was tested. An extrapolation chamber is a parallel-plate ionization chamber that allows the variation of its sensitive air volume. This chamber was used previously for low-energy radiation beams and showed results within the international recommended limits. The aim of this work is to perform some characterization tests (saturation curve, polarity effect, ion collection efficiency and linearity of response) considering the chamber depth of 1.25 mm in the radiation qualities for computed tomography beams at the LCI. The results showed to be within the international recommended limits.

Vlado Valković

L. Yu. Krestinina, S. S. Silkin, M. O. Degteva et al.

The paper describes for the first time the results of the radiation effect study using the example of the analysis of circulatory system disease mortality in newly established cohort combining the population exposed in 1950–1960 due to 2 radiation incidents in the Southern Urals (the Techa River and East-Urals radioactive Trace). The cohort consists of 60,205 people. Over a 65-year follow up period 14,830 deaths from all diseases of the circulatory system were registered. Out of this number 6,163 deaths were from ischemic heart disease, and 4,388 deaths were from cerebrovascular diseases. Analysis was performed on the basis of individualized estimates of dose accumulated in muscle tissue (both internal and external components of the dose), calculated with new Techa River Dosimetry System 2016. As per the latest calculations, mean dose to muscle tissue in members of the combined cohort was 34 mGy, maximum dose was 995 mGy. Simple parametric model of excess relative risk (ERR) was used in the analysis. The number of person-years at risk was 1836,203. The findings of the analysis show linear increase of mortality risk per unit dose from all the disease of circulatory system (ERR/100 mGy was 3%; 95% CI: 0,8%; 5,2%) and from ischemic heart disease (ERR/100 mGy was 9,2%; 95% CI: 5,4%; 13,5%). with 15-year latent period. No statistically significant increase in mortality from the cerebrovascular diseases in the combined cohort of the population exposed in the Southern Urals over a 65-year period received evidence. The obtained results are in good agreement with those received in the analysis of the effect in the Techa River Cohort in 2013. The latter covered a 53-year period (with minimum latent period of 15 years) and revealed statistically significant linear dose response for all diseases of the circulatory system (ERR/100 mGy – 0.036) and ischemic heart disease (ERR/100 mGy – 0.056).

Cyro Teiti Enokihara

The availability of gamma ray irradiators in Brazil increased the possibilities of treatments of gemstones for color   enhancements. One of the minerals with a very high potential of these treatments is quartz, a very widespread mineral with many colored commercial varieties.  A specific variety of quartz showing a green color in nature or induced artificially by radiation gamma (60Co) is quite rare. In Brazil the widely scattered geode occurrences from Quaraí at Brazil southernmost tip to Uberlandia in Minas Gerais is one of these. Quartz from these occurrences have been formed by strong hydrothermal activities. That way much quartz crystals showed a very fast growth history facilitating the  formation of growth defects and the uptake of water in form of micro inclusions, molecular water, silanol (Si-OH) and OH. In the present work the material analyzed is from hydrothermal regimes  located near the towns Entre Rios and Quaraí. To characterize these materials  analyses have been made by ICP, NAA, electron microscopy, water loss  techniques and UV-VIS and NIR-FTIR spectroscopic measurements. Silanol complexes are found, which by radiation due to gamma rays form the color center NBOHC (Non-Bonding Oxygen Hole Center), showing absorption between 590 to 620 nm and leaving a transmission window at about 550nm, responsible for the green color. The spectroscopic water determination showed less molecular water (up to 2300 ppm by weight), probably due to remaining silanol complexes.The water content with up to 3200 ppm by weight exceeds the amount of charge balancing cations (Fe, Al, Li).

Reginaldo Gonçalves Leão Jr, Rômulo Verdolin Sousa, Arno Heeren Oliveira et al.

Neste trabalho foi empregado o Método de Monte Carlo para a simulação de campos clínicos de radioterapia que serão posteriormente utilizados para a calibração de pequenos campos de radiocirurgia. O código de transporte de radiação utilizado foi o EGSnrc e seus derivados, BEAMnrc e DOSXYZnrc, empregados para a construção e simulação do acelerador e objeto simulador de água, respectivamente. Foram simulados três campos de fótons quadrados com dimensões de 4x4 cm², 10x10 cm² e 20x20 cm², todos com energias nominais de 6 MeV. Os resultados foram comparados com valores experimentais obtidos na rotina de calibração e dosimetria do acelerador real que foi modelado. Para simulações foram utilizandas 109 histories, PCUT=0,01 MeV e ECUT = 0,7 MeV. A máxima incerteza relativa encontrada nas regiões de interesse foi de 4%.  A concordância do dimensionamento lateral dos campos manteve-se em níveis superiores a 98% enquanto as doses em profundidade, no pior dos casos, apresentaram concordância superior a 90%  chegando a valores de concordância superiores a 97% em pequenas profundidades.. Apesar das imprecisões detectadas no processo de simulação, o modelo foi considerado válido devido à qualidade dos dados em posições e profundidades importantes para a futura calibração das doses em pequenos campos. Dados ilustrativos do comportamento do modelo para a simulação destes pequenos campos também são apresentados no final do texto.

V. Yu. Golikov, I. K. Romanovich

The article presents a methodology for assessing the radiological criteria for the use of the territory (a land plot with buildings) with residual radioactive contamination from the so-called “green area”, i.e., complete release from radiation control until a number of restrictions are imposed on the use of the territory. In accordance with the further use of the territory, a range of scenarios and pathways for the exposure of the population was considered. A set of models and their parameters, corresponding to the number of the considered pathways of exposure, was defined. Assuming a uniform distribution of a radionuclide with a unit concentration in the source zone, the distribution of effective doses for the population living in the territory with the residual radioactive contamination for different irradiation scenarios was calculated by stochastic modeling, 95% of the quantile of which was attributed to the dose in the representatives of the critical population group. Next, the value of radiological criteria, depending on the implemented scenario, was determined as the ratio of the dose constraint EL = 0,3 mSv/yr and 95% quantile in the distribution of the effective dose from a unit contamination. The numerical values of radiological criteria for the presence of radionuclides in the soil are presented, both for the radiation scenarios that correspond to the permanent residence of the population in the contaminated territory and for recreational use. A further consideration is given to the so-called worker scenario, which corresponds to the limited time spent on the contaminated territory and the simultaneous effects of radionuclides contained both in the soil and in the construction of the buildings. A comparison of the results of the own calculations with the data of other authors was carried out.

L. V. Repin, A. M. Biblin, N. M. Vishnyakova

The implementation of the State program of the Russian Federation “Development of nuclear power industry”, Federal target program «Ensuring Nuclear and Radiation Safety from 2016 to 2020 and up to 2030», introduction of new imaging modalities in medicine that are associated with high patient and staff doses, poor public awareness of the presence and level of hazard of natural sources of ionizing radiation determine the relevance of the current study. The aim of the study was to develop the effective methods of risk communication for the improvement of the radiation protection and safety of the population, to introduce these methods in the daily practice of Rospotrebnadzor and, eventually, to assist in the formation of a risk-oriented society in the Russian Federation. Currently, Russian-language terminology in the field of risk communication is not developed; Russian terms are frequently just poor adapted/translated versions of English terms. This manuscript is focused on the definition of the basic concepts of risk communication and the formation of uniform terminology in the field of the radiation safety of the population. A glossary of basic terms in the field of riskcommunication is attached to the manuscript. The authors, considering the analysis of scientific data, suggest the following definition of risk communication: a process of interaction with other participants that is intentionally initiated by one of the participants in the information field of risk and is aimed at the evaluation of the attitudes on risk, their formation or change in other participants; formation or change of own attitudes on risk.

I. P. Stamat, E. P. Lisachenko

In the Sanitary Rules SR 2.6.1.1292-03 and SR 2.6.6.1169-02 classification of the industrial waste containing naturally occurring radioactive materials is adopted in accordance to the values of their effective specific activity Aeff. In a case of the disturbed equilibrium in 238U and 232Th series it is necessary to take into consideration actual contribution of the separate natural radionuclides of the mentioned series into the value of gamma dose rate of the waste. This will permit to avoid unjustified overestimating or understating of the waste category which prevents as unjustified expenditures on their treating so undertaking of the necessary measures providing radiation safety.

Lucas Rodrigues Santos, Vitor Vivolo, Marcus Vinícius Teixeira Navarro et al.

This work shows the peak voltage measurements for several beam filtrations used in diagnostic radiology, using two types of non-invasive detectors; a voltage meter and a high-resolution spectrometer. The technique chosen for the voltage peak measurements with the spectrometer was the endpoint. The results were compared to the measured ones and showed good similarity to the nominal values. However the voltage meter detector used in this work presented errors for heavier filtrations.

J. Vives i Batlle, L. Sweeck, J. Wannijn et al.

mansour zabihzadeh

Gonad shielding has been advocated to reduce radiation exposure in patients undergoing pelvic radiography. The aim of this study is to evaluate the frequency and accuracy of gonad shield placement in patients undergoing pelvic radiography. A retrospective study was performed on 1230 anteroposterior (AP) pelvic radiographs of 939 children under 16 years old. All the radiographs were reviewed to determine the frequency of gonad shielding and to evaluate whether gonad shields were correctly positioned when they are used. The gonad shield was present in 82 radiographs (30 girls and 52 boys) and was completely disregarded in 1148 radiographs. From 82 images which shield was present, the gonad shields adequately positioned in 28 radiographs (3 girls and 25 boys) and in the remaining 54 radiographs, the shield did not adequately protected the gonads due to incorrect placement of the shield. The inaccuracy placement and absence of gonad shields were more common in girls than boys (P-value < 0.05). More care should be taken to correctly positioning of the gonad shields in boys and its usage should be encouraged. However, the practice of ovarian shielding is not an effective way to reduce radiation exposure in girls undergoing pelvis radiography.

A. V. Vodovatov, S. A. Kalnitsky, M. I. Balonov et al.

We introduce a system of Diagnostic Reference Levels (DRLs) for patients medical exposure for national health care practice implementation. DRLs are an effective way of the patient radiation protection through the optimization of the medical exposure. The paper discusses and compares different methods of determining the DRLs based on measured and/or calculated quantities of patient’s dose: dose area product (DAP), entrance surface dose (ESD) and an effective dose. Distributions of different dose quantities in different Saint-Petersburg clinics are shown on the example of chest PA examinations. The results are compared with the data from other sources. Regional DRLs for Saint-Petersburg are proposed.

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