{"results":[{"id":"doaj_10.15392/2319-0612.2025.2633","title":"A neoteric technique to validate radon-222 transport modelling from a gold mine tailings dam","authors":[{"name":"Frank S. Komati"},{"name":"O. M. Ntwaeaborwa"},{"name":"R.  Strydom"}],"abstract":"\nThe Gaussian Industrial Source Complex Short Term 3 (ISCST3) model as applied to radon-222 emitted from tailings dams has not been properly validated for radon-222 dispersion modelling. In an attempt to validate the model, the concentrations of radon-222 and its progenies/daughters were measured at various points around a tailings dam. To verify that the measured radon-222 is from the tailings dam, a technique combining both gas and daughters ages with source apportionment method was developed. Model was validated by isolating radon-222 from different sources using the “age” of the gas approach and applying back trajectory calculations to identify the origin of the radon gas measured at points downwind. As predicted by the model, the origin of the radon emission was traced back to the tailings. The model was further validated by comparing measured data to model outputs and applying standard model validation statistics to validate and quantify the agreement between predicted and measured data. Model validation from statistical analysis showed a constant trend with minimum variability in the Index of Agreement (IOA), Normalized Mean Square Error (NMSE), and Fraction of Predictions method within a factor of two (FAC2) values. The analyses were based on the model prediction results over five days of measurements covering both morning and afternoon. There was an under prediction in the Fractional Bias (FB) and Geometric Mean bias (MG) in the afternoon of day 1. In addition, the model performed poorly in the afternoon of day 3.\n","source":"DOAJ","year":2025,"language":"","subjects":["Medical physics. Medical radiology. Nuclear medicine","Radioactivity and radioactive substances"],"doi":"10.15392/2319-0612.2025.2633","url":"https://bjrs.org.br/revista/index.php/REVISTA/article/view/2633","is_open_access":true,"published_at":"","score":69},{"id":"doaj_10.21514/1998-426X-2024-17-4-35-42","title":"Results of individual dosimetric monitoring of the hands skin for personnel engaged in working with radiopharmaceuticals","authors":[{"name":"E. N. Shleenkova"},{"name":"S. Yu. Bazhin"},{"name":"V. Yu. Bogatyreva"}],"abstract":"With the active development and wide use of positron emission tomography, ensuring radiation safety in matters of irradiation of the skin of the hands of personnel, has become very important. Work with radiopharmaceuticals labeled with various radionuclides is characterized by fairly close contact with a source of ionizing radiation, during which the skin of the hands can be irradiated in significant doses. Thus, the effect of ionizing radiation on the skin of the hands is one of the main problems of radiation protection of personnel at nuclear medicine centers. The work of personnel at nuclear medicine centers, depending on the nature of the actions performed, can be divided into two types: predominantly manual processes (nurses – packaging and administration of drugs, analytical chemists – quality control) and predominantly automated processes (radiochemical engineers – synthesis, packaging into vials). The individual equivalent doses to the skin of the hands of nurses, analytical chemists and radiochemical engineers working with 18F-based radiopharmaceuticals were estimated using thermoluminescence dosimetry with individual dosimeters calibrated in terms of Hp(0.07). The maximum annual value obtained fo radiochemical engineers was 7.8 mSv, which is 1.56% of the dose limit, and for analytical chemists it was 171 mSv, which is 34% of the dose limit (mean value was 28 mSv, median was 8.8 mSv, minimum value was 4.6 mSv). At the same time, nurses, who are mainly engaged in the packaging and administration of radiopharmaceuticals, have higher values of annual doses in the skin of the hands (mean value – 114 mSv, median – 56 mSv, minimum value – 1.3 mSv). The maximum value of the annual dose in the skin of the hands, recorded during the work, for a nurse was 573 mSv, i.e. the dose limit of 500 mSv was exceeded. The results of the work indicate that specialists involved in manual processes when manipulating radiopharmaceuticals require special attention from the standpoint of individual dosimetric control of the irradiation dose to the skin of the hands and compliance with radiation safety requirements.","source":"DOAJ","year":2025,"language":"","subjects":["Medical physics. Medical radiology. Nuclear medicine","Radioactivity and radioactive substances"],"doi":"10.21514/1998-426X-2024-17-4-35-42","url":"https://www.radhyg.ru/jour/article/view/1101","is_open_access":true,"published_at":"","score":69},{"id":"doaj_10.21514/1998-426X-2025-18-2-77-86","title":"Preconception exposure of mothers: The review of epidemiological research","authors":[{"name":"S. F. Sosnina"}],"abstract":"A review of epidemiological research of the effects of preconception (prior to conception) radiation exposure to a mother’s body was presented. The anatomical and physiological characteristics that affect radiosensitivity and radioresistance of female reproductive system were reported. Biological prerequisites accounting for different effects of radiation exposure to animals and humans were indicated. The results that were published in open access on epidemiological assessments of the effects of preconception exposure of mothers to the health of their offspring were described based on various cohorts as examples. Analysis of the research work was performed for the cohort of the offspring of atomic bomb survivors in Japan, among the offspring of the individuals affected by radiation accidents and nuclear weapon tests, among the population of the sites with high natural level of radiation. The results of research work among the offspring of female patients exposed to diagnostic and therapeutical radiation and of the offspring of the mothers who were in contact with ionizing radiation sources at workplaces were presented. A special attention was paid to specifics of standardization of occupational exposure of female personnel according to national and international approaches. Generally, it was demonstrated that despite a wide range of epidemiological research works there is still no clear understanding of the effects of preconception exposure of mothers to their offspring. The total results of the analysis of the effects of maternal exposure in preconception period are quite controversial and usually involve a range of uncertainties. In the course of such sort of epidemiological research the following difficulties are indicated: poor verification of medical outcomes, primary data based on questionnaire surveys, lack of detailed information on individual exposure parameters, low statistical power of research works and too short period of follow up of the cohort under research. For this reason, the necessity of further analysis of the effects of exposure of female body was indicated involving detailed risk coefficients of unfavorable reproductive outcomes. Prospective trends for epidemiological analysis of preconception exposure of mothers were indicated. Feasibility of assessment of long-term preconception radiation exposure was described based on the cohort of female workers of Mayak Production Association that is the leading atomic enterprise in the national history.","source":"DOAJ","year":2025,"language":"","subjects":["Medical physics. Medical radiology. Nuclear medicine","Radioactivity and radioactive substances"],"doi":"10.21514/1998-426X-2025-18-2-77-86","url":"https://www.radhyg.ru/jour/article/view/1154","is_open_access":true,"published_at":"","score":69},{"id":"doaj_10.15392/2319-0612.2024.2708","title":"Modeling nuclear fuel assemblies through porous zones in a Small Modular Reactor: fluid dinamic considerations","authors":[{"name":"Rebeca Cabral Gonçalves"},{"name":"Geovana Carvalho Silva"},{"name":"Fernando Lage Araújo Schweizer"},{"name":"Pedro Andrade Maia Vinhas"},{"name":"Keferson de Almeida Carvalho"},{"name":"Tiago Augusto Santiago Vieira"},{"name":"Vitor Vasconcelos Araújo Silva"},{"name":"Graiciany de Paula Barros"},{"name":"Andre Augusto Campagnole dos Santos"}],"abstract":"\nThis work aims to qualify the use of porous zones for representing fuel assemblies of a proposed SMR reactor in numerical models in other to reduce the computational demand required to study these structures. It employs computational fluid dynamics (CFD) methods to calculate the conservation equations of mass, momentum, and energy within a control volume. Initially, a detailed geometry of the fuel assembly was created and used for isothermal simulations. Based on the results of pressure drop and velocity, equations were used to calculate the coefficients of porosity and pressure drop of the system. These were then utilized to configure a second geometry, consisting of hexahedros divided into thirteen sub-regions according to their cross-sectional area, each having different porosities and pressure drop coefficents. Finally, the results of the two simulations were compared to verify their convergence to allow the use of the porous geometry. The outcomes suggests that, for models with a control volume significantly larger than a single fuel assembly, such as a complete nuclear reactor vessel, the use of porous zones is advantageous, as the variations in average velocity and pressure drop along the length of the structure are small, with the maximum axial velocity variation of -10.99%. However, if the objective is to conduct a more detailed analysis of the entire assembly, this strategy is not recommended, since some specific aspects of fluid behavior are not well capturated, such as radial velocity differences. \n","source":"DOAJ","year":2025,"language":"","subjects":["Medical physics. Medical radiology. Nuclear medicine","Radioactivity and radioactive substances"],"doi":"10.15392/2319-0612.2024.2708","url":"https://bjrs.org.br/revista/index.php/REVISTA/article/view/2708","is_open_access":true,"published_at":"","score":69},{"id":"ss_90dc2a47c2d0bacf721153a99b8d1a9599abdc41","title":"Mushrooms as an indicator of radioactive contamination","authors":[{"name":"M. Vićentijević"},{"name":"Dubravka Vuković"},{"name":"Đorđe Guzijan"},{"name":"Jelena Vićentijević"},{"name":"Marija Pavlović"},{"name":"Slobodan Stanojević"}],"abstract":"Plant species, and through them humans, can be threatened by radioactive substances even in cases of low radioactivity in certain parts of the ecological chain. All this is a consequence of the bioaccumulation of certain radionuclides in some plant species, which become \"bioindicators\", and sometimes they can have significantly large accumulations of radioactive substances and therefore be dangerous for human consumption. Their determination facilitates the monitoring of the level of radioactive contamination of an ecosystem from the place of origin to man. Mushrooms can represent a bioindicator of radioactive contamination, and this high radioactivity is associated with the possibility of binding radionuclides from the forest floor for several years. The Department for Radiation Hygiene, at the Scientific Institute of Veterinary Medicine of Serbia in Belgrade, deals with veterinary-sanitary and phyto-sanitary control in border and internal traffic in the Republic of Serbia. During 2020-2024. 133 samples of mushrooms that are used for human consumption in several forms: fresh, canned and dried or in powder were carried out using the gamma spectrometric method. Based on the obtained results of radioactivity measurements, we can conclude that the activities of anthropogenic radionuclides, in our case 137Cs, were within the permitted limits for the given forms of the product. Fresh mushrooms from internal traffic, forest mushrooms, had the highest activity, where the measured activity of 137Cs was in the ratio of 0.34-37.25 Bq/kg, the value of which was slightly higher but still below the permitted limits prescribed by our regulations. The radioactivity of the environment is constantly decreasing after the nuclear accidents in Chernobyl and Fukushima, but plant species, such as mushrooms, can be good sources of pollution in certain parts of the ecosystem due to their ability to accumulate and bind radioactive substances. This is why constant radiation-hygiene control of samples from the environment is necessary, because this is the only way we can ensure correct and radiation-free products for human consumption.","source":"Semantic Scholar","year":2025,"language":"en","subjects":null,"doi":"10.5937/svs25247v","url":"https://www.semanticscholar.org/paper/90dc2a47c2d0bacf721153a99b8d1a9599abdc41","is_open_access":true,"published_at":"","score":69},{"id":"ss_4378bd51e911817baa9d97f8665b6b4eebe4b790","title":"Exploring the alteration of environmental radioactivity in terms of compositional elements of heavy minerals in an anthropogenically affected urban river: Radiological and ecological risks assessment.","authors":[{"name":"Sayma Zahan Akhi"},{"name":"R. Khan"},{"name":"Md. Samium Basir"},{"name":"Md. Ahosan Habib"},{"name":"Mohammad Amirul Islam"},{"name":"K. Naher"},{"name":"A. M. Idris"},{"name":"M. H. Khan"},{"name":"Saad Aldawood"},{"name":"Dhiman Kumer Roy"}],"abstract":"This study explored the alteration of naturally occurring radioactive materials (NORMs: 226Ra (≈238U), 232Th, 40K) in an anthropogenically disrupted urban river-basin (Turag, Bangladesh) in terms of constitutional substances (Sc, Ti, V, Fe, La, Ce, Sm, Eu, Tb, Dy, Ho, Yb, Lu, Hf, Ta, W, Th, U) of heavy-minerals. Average activity concentrations of 226Ra (≈238U), 232Th, and 40K were 41.5 ± 12.9, 72.1 ± 27.1, and 639 ± 100 Bqkg-1, respectively which were relatively higher compared to crustal origin. ∑REEs, Ta, W, Th, and U were ~2 times higher compared to crustal values with Ce and Eu-anomalies. APCS-MLR and PMF receptor models were used to determine the various anthropogenic and/or geogenic sources of NORMs and elements. Layer-wise variations of NORMs and elements were observed to trace the response of sedimentary processes towards the incoming pollution load. Presence of REEs indicates moderate degree of ecological risk to aquatic biota. However, carcinogenic risk (3.84 × 10-4 Sv-1) were significantly higher than threshold limit.","source":"Semantic Scholar","year":2024,"language":"en","subjects":["Medicine"],"doi":"10.1016/j.marpolbul.2024.116694","url":"https://www.semanticscholar.org/paper/4378bd51e911817baa9d97f8665b6b4eebe4b790","is_open_access":true,"citations":7,"published_at":"","score":68.21000000000001},{"id":"ss_4080b6eb822ce0e3a35a255bb9df785748aa2536","title":"Study on the actual particle size, activity concentration, and migration process adsorption behavior of radioactive substances in liquid effluents from nuclear power plants","authors":[{"name":"Zhenyu Jiang"},{"name":"Jun Xiong"},{"name":"Yuelong Pan"},{"name":"Jie Hu"},{"name":"Yujia Chen"},{"name":"Shuhua Yin"},{"name":"Yihong Yan"}],"abstract":"Radionuclides emitted by nuclear power plants may have effects on the environment and public health. At present, research on radioactive material effluent in the industry mainly focuses on the treatment of radioactive effluent and the particle size distribution of the primary circuit. There is little research on the particle size of radioactive material during the migration process outside the primary circuit system, as well as the flocculation precipitation and other enrichment phenomena during the collection process of effluent. Therefore, this study relies on the sampling of effluent from an in-service nuclear power plant to measure its radioactivity level by particle size range. At the same time, the mixing process of effluent is simulated in the laboratory to simulate the adsorption behavior of effluent during the migration process. It was found that in the activity concentration of detectable radioactive nuclides in the effluent samples, more than 95% of radioactive nuclides exist in the liquid with particle sizes less than 0.1μm, while particle sizes greater than 0.45 μm account for less than 5%. After the sample was filtered by the demineralizer, the radioactive activity decreased. The flocculation precipitation in the waste liquid of the waste water recovery system has a certain contribution to the enrichment of nuclides. With the extension of time, the enrichment of transition elements such as cobalt and manganese is particularly obvious, so that it is distributed in the liquid again with a large particle size. In addition, large particle size substances such as colloids in seawater have a certain adsorption effect on radionuclides, which will lead to its aggregation effect again.","source":"Semantic Scholar","year":2024,"language":"en","subjects":null,"doi":"10.3389/fenrg.2024.1352706","url":"https://www.semanticscholar.org/paper/4080b6eb822ce0e3a35a255bb9df785748aa2536","pdf_url":"https://www.frontiersin.org/articles/10.3389/fenrg.2024.1352706/pdf?isPublishedV2=False","is_open_access":true,"citations":1,"published_at":"","score":68.03},{"id":"doaj_10.15392/2319-0612.2024.2435","title":"Analysis of exposure indices from digital radiography exams","authors":[{"name":"Isadora Veiga da Rosa"},{"name":"Janine Hastenteufel Dias"},{"name":"Rochelle Lykawka"},{"name":"Mauricio Anes"},{"name":"Luany Nobre Furlan"},{"name":"Alexandre Bacelar"}],"abstract":"Radiography is a crucial diagnostic imaging modality in clinical practice, with persistent challenges in digital radiography regarding the level of exposure. The International Electrotechnical Commission standardized the Exposure Index (EI) and Deviation Index (DI) in digital systems, aiming to improve the assessment of radiation exposure. Each exam has an associated Target Exposure Index (EIT), representing the balance between radiation dose and image quality. This study analyzed the EI and DI of digital radiographs at a university hospital, using a database of 71,760 radiographs. The analysis considered the action limits as suggested by the American Association of Physicists in Medicine (AAPM). The group of exposures carried out in radiography rooms presented a DI of 1.2, while that of exposures carried out on mobile equipment, 2.4. In contrast, the first group presented standard deviation values between 1.5 and 3.9, while the second, between 1.8 and 2.6. These results suggest that exposures performed using Automatic Exposure Control (CAE) differ less from EIT, however, radiographic techniques were more standardized among exams with mobile equipment, performed with manual selection of exposure parameters, as these exams presented a smaller DI dispersion range. The creation of an automated tool in Google Looker Studio facilitated interactive data analysis, presenting information by anatomical region and view, with the potential to continuously monitor radiological practices. For certain incidences, the average DI values obtained differed substantially from the ideal value, which requires optimization actions, investigation into the definition of adequate EIT and calibration of the CAE. The study provided a detailed overview of local radiographic practices, highlighting priorities for optimization and standardization actions.","source":"DOAJ","year":2024,"language":"","subjects":["Medical physics. Medical radiology. Nuclear medicine","Radioactivity and radioactive substances"],"doi":"10.15392/2319-0612.2024.2435","url":"https://bjrs.org.br/revista/index.php/REVISTA/article/view/2435","is_open_access":true,"published_at":"","score":68},{"id":"doaj_10.21514/1998-426X-2024-17-3-16-28","title":"Dynamics of \u003csup\u003e137\u003c/sup\u003eCs concentrations in cow milk in the districts of Bryansk region","authors":[{"name":"S. V. Fesenko"},{"name":"N. N. Isamov"},{"name":"E. S. Emlyutina"},{"name":"E. I. Karpenko"},{"name":"V. A. Goryainov"}],"abstract":"The publication continues the series of research addressed to the dynamics of 137Cs concentrations in agricultural products after the Chernobyl accident. The purpose of the present paper was to analyze the data describing the changes of 137Cs concentrations in cow milk. The information on countermeasures in animal breeding is presented, the system of radiological monitoring of milk contamination is described. It is shown that the dynamics of 137Cs concentrations in milk was seriously affected by the implementation of agrotechnical and veterinary measures. Effective half-lives of 137Cs concentrations in milk in the first period after the accident (1987-1992) ranged from 1 to 2.0 years. In the subsequent period (1991-2015), the reduction of milk contamination slowed down and the half-lives ranged from 5 to 25 years depending on the scope of remediation works and 137Cs aging in the soil.","source":"DOAJ","year":2024,"language":"","subjects":["Medical physics. Medical radiology. Nuclear medicine","Radioactivity and radioactive substances"],"doi":"10.21514/1998-426X-2024-17-3-16-28","url":"https://www.radhyg.ru/jour/article/view/1055","is_open_access":true,"published_at":"","score":68},{"id":"doaj_10.15392/2319-0612.2024.2341","title":"The radioactive contamination of ground and surface water near a uranium mine in Malawi","authors":[{"name":"L. J. Majawa"},{"name":"O. A. Jegede"},{"name":"V. M. Tshivhase"},{"name":"B. T. Chobeka"},{"name":"T. D. Mokgele"}],"abstract":"Ground and surface water in the uranium mining area of Kayelekera in Malawi was assessed for concentration levels of radioactive metals. Potential health risks associated with the intake of these metals in drinking water from various sources were also estimated. Surface, groundwater and mine discharge water samples were collected and analysed for radio elemental concentration using inductively coupled plasma mass spectrometry analytical technique. The results indicated a high concentration of 238U in water samples from lower Sere river. The activity concentrations of 238U, 232Th and 40K were however below WHO recommended limit. Health risk assessment using average committed effective dose were below the global average. Excess lifetime cancer risk values with an average of  for borehole water was calculated and found to be below the global average. Radiologically, the water quality of Kayelekera area post uranium mining activities has not been compromised, however close monitoring and treating of drinking water is recommended","source":"DOAJ","year":2024,"language":"","subjects":["Medical physics. Medical radiology. Nuclear medicine","Radioactivity and radioactive substances"],"doi":"10.15392/2319-0612.2024.2341","url":"https://bjrs.org.br/revista/index.php/REVISTA/article/view/2341","is_open_access":true,"published_at":"","score":68},{"id":"ss_7488b0938a26e1e1cd7e7ef4e80a0171c64fc8dd","title":"Requirements for Ensuring the Safety of Firefighters of FRS CR When Responding to a Fire in Buildings with the Potential Presence of Radioactive Substances","authors":null,"abstract":"The Fire and Rescue Service of the Czech Republic occasionally intervenes in buildings and objects where radioactive or nuclear materials are stored or used. In such cases, special care must be taken to ensure adequate protection of all persons from possible exposure to ionizing radiation. This is especially important for rescuers in the vicinity of the fire and radioactively contaminated environments. To minimize their exposure, it is necessary to monitor the radiation levels and the concentration of radioactivity in the air using suitable detectors and other special monitoring devices. The results of these measurements should be expressed in recognized quantities and units, the level of which continuously reflects the radiation risk in a given location. This needs to be constantly monitored and maintained within certain limits or benchmarks in accordance with relevant standards and regulatory requirements. The paper discusses the approach of firefighters to ensure sufficient radiation protection in line with national regulations.","source":"Semantic Scholar","year":2023,"language":"en","subjects":null,"doi":"10.36682/sss_2022_11","url":"https://www.semanticscholar.org/paper/7488b0938a26e1e1cd7e7ef4e80a0171c64fc8dd","pdf_url":"https://doi.org/10.36682/sss_2022_11","is_open_access":true,"published_at":"","score":67},{"id":"ss_329012d8017a179bfe03a7b079f4d4619da48753","title":"Real-Time Monitoring Method for Radioactive Substances Using Monolithic Active Pixel Sensors (MAPS)","authors":[{"name":"Yongchao Han"},{"name":"Shoulong Xu"},{"name":"Youjun Huang"}],"abstract":"This study presents a real-time monitoring technique for radioactive substances that meets safety management needs. We studied the accumulation characteristics of radiation response signals of monolithic active pixel sensors (MAPSs) based on their response and discrimination ability to gamma (γ) photon or neutron radiation. The radiation status of the radioactive substances was determined by monitoring the accumulation data of radiation responses. As per the results, Am-Be and 252Cf radiation response signals are primarily concentrated in the range of 0–70 pixels. Response signals of 60Co and 137Cs γ-ray were concentrated in two regions; there was a peak in the region with a pixel value of less than 50, and a plateau in the region with a pixel value of more than 75. Therefore, the results are able to discriminate between spectra. Furthermore, we designed a radioactivity monitoring system that is able to examine multiple radioactive materials. Its working principle is that a change in the accumulation of radioactivity monitoring data indicates a radiation change during the last accumulation cycle. This study provides vital technical support for the long-term supervision of radioactive substances.","source":"Semantic Scholar","year":2022,"language":"en","subjects":["Computer Science","Medicine"],"doi":"10.3390/s22103919","url":"https://www.semanticscholar.org/paper/329012d8017a179bfe03a7b079f4d4619da48753","pdf_url":"https://www.mdpi.com/1424-8220/22/10/3919/pdf?version=1653206649","is_open_access":true,"citations":6,"published_at":"","score":66.18},{"id":"ss_3695ad579e507ba2219416cd533be532557ce220","title":"Estimation of radioactivity and dose equivalent rate by combining Compton imaging and Monte Carlo radiation transport code.","authors":[{"name":"Yuki Sato"}],"abstract":"In a radiation environment, such as the decommissioning site of a nuclear power station, visualization of the distribution of radioactive substances and estimation of the dose equivalent rate around the site can help reduce the exposure dose of workers and plan their work. The author has developed a method of visualizing the existence of a radiation source using a gamma-ray imager, estimating its radioactivity, and estimating the dose equivalent rate around the source. A Compton camera, which is a gamma-ray imager, is used to visualize the existence of a137Cs radiation source and estimate its radioactivity, and a three-dimensional (3D) model of the region around the source is generated using a simultaneous localization and mapping device based on 3D light detection and ranging. Next, the dose equivalent rate around the source is calculated by importing the 3D model data and radioactivity information into a particle and heavy ion transport code system. The validity of the calculated dose equivalent rates is also confirmed by comparing them with values measured using a survey meter. This method can be used not only to simply visualize a source and calculate the dose equivalent rate around it but also to evaluate how addition of shielding or removal of contaminated objects can contribute to reducing the dose equivalent rate.","source":"Semantic Scholar","year":2022,"language":"en","subjects":["Medicine"],"doi":"10.1016/j.apradiso.2022.110254","url":"https://www.semanticscholar.org/paper/3695ad579e507ba2219416cd533be532557ce220","is_open_access":true,"citations":1,"published_at":"","score":66.03},{"id":"doaj_10.15392/bjrs.v10i2A.1760","title":"Ethylene-vinyl acetate detector exposed to gamma radiation and evaluated via principal component regression","authors":[{"name":"Lucas N Oliveira"},{"name":"Eriberto Nascimento"},{"name":"Patricia  de Lara Antonio"},{"name":"Linda V.E. Caldas"}],"abstract":"Ethylene-vinyl acetate (EVA) is the flexible plastic material commonly used in industries. The EVA samples, in green, white and black colors were irradiated with absorbed doses of 0.01 kGy up to 10.0 kGy using a 60Co Gamma Cell-220 system, and the Fourier Transform Infrared (FTIR) spectrophotometry technique was used for evaluating the samples. This work aimed to investigate EVA samples in measurements with gamma radiation, analyzing the linearity through the Principal Component Regression (PCR) method and its sensitivity. For sensitivity and linearity, the green samples showed the best results, followed by white and black EVA samples. The PCR method inflated gradually the number of principal components, then reducing the residuals between the measured and calculated values, consequently obtaining maximum linearity of 1.000 for all EVA samples. In conclusion, the FTIR was adequate for the acquisition of absorbance spectra, the linearity via PCR and sensitivity showed good results indicating that the EVA detectors can be useful in radiation measurements.","source":"DOAJ","year":2022,"language":"","subjects":["Medical physics. Medical radiology. Nuclear medicine","Radioactivity and radioactive substances"],"doi":"10.15392/bjrs.v10i2A.1760","url":"https://bjrs.org.br/revista/index.php/REVISTA/article/view/1760","is_open_access":true,"published_at":"","score":66},{"id":"doaj_10.15392/bjrs.v8i3B.451","title":"Assessing the management system to demonstrate the safe of transport of radioactive material","authors":[{"name":"Natanael de Carvalho Bruno"},{"name":"Patricia Morais Mattar"},{"name":"André Teixeira Pontes"}],"abstract":"Radioactive materials are used for medical purposes, to avoid greenhouse gas effect in energy production plants, food and other products sterilization, research and sophisticated measurement technologies. Transport of radioactive material involves a range of actors each one having specific responsibilities for safety. Through Management System, consignors and carriers fulfil objective evidences that safety requirements are met in practice, while compliance assurance programs allow regulatory bodies and/or competent authorities to demonstrate to society that public, workers and environment are protected. According to IAEA, safety has to be achieved and maintained through an effective management system. This system should integrate all elements of management so that requirements for safety are established and applied consistently with other requirements, including those related to human performance, quality and security, and so that safety is not committed by other requirements or demands. CNEN, the Brazilian Regulatory Body for the safe transport of radioactive materials, adopt international standards to establish safety requirements deemed relevant for protection of health and minimization of danger to life and property, and to provide for the application of these standards. Seeking for continuous improvement, the adherence of the practices adopted by Transport Safety Unit (TSU) against the recommendations from the IAEA was assessed. This assessment led to the elaboration of proposals for improvement as well as the identification of good practices. The methodology used to perform this assessment was the SARIS methodology, developed by the IAEA. This paper will describe the most relevant findings of this study.","source":"DOAJ","year":2021,"language":"","subjects":["Medical physics. Medical radiology. Nuclear medicine","Radioactivity and radioactive substances"],"doi":"10.15392/bjrs.v8i3B.451","url":"https://bjrs.org.br/revista/index.php/REVISTA/article/view/451","is_open_access":true,"published_at":"","score":65},{"id":"doaj_10.15392/bjrs.v9i1A.1573","title":"Oxide layer characterization by XRD and Rietveld refinements in maraging steel 300 aged in steam atmosphere","authors":[{"name":"Vanessa Sanches Pereira da Silva"},{"name":"José Roberto Ferreira Neto"},{"name":"Silvia Lucas Ferreira da Silva"},{"name":"Diogo Costa de Oliveira"},{"name":"Fábio de Camargo"}],"abstract":"Maraging steels are martensitic steels hardened by precipitation of intermetallic compounds in thermal aging, with good machining properties and high strength, fracture toughness and corrosion resistance, being used in aircraft parts and rocket motor-case, tooling applications and nuclear plants. During thermal aging in steam atmosphere a protective and corrosion resistant oxide layer is formed over the bulk. In this work, conventional Bragg-Brentano geometry was used to identify the phases formed in four specimens of maraging steel grade 300 with different surface finishes that were previously solution annealed twice at (950 ± 5) °C for 1 h, air-cooled, and submitted to oxidation process under positive pressure about 1.5 kPa of steam at (480 ± 5) °C for 6 h, followed by forced air-cooling. Diffraction patterns were measured employing CuKα radiation, ranging 20º \u003c 2θ \u003c 85º and the Rietveld method was used to better characterize the structures identified. Through Rietveld refinements it was possible to conclude that the layer formed during heat treatment process is constituted by a transition metallic phase with a quasi-cubic face centered unit cell, and an oxide layer that includes hematite, magnetite and a spinel structure type MFe2O4, where M could be an alloying element, for all analyzed samples.","source":"DOAJ","year":2021,"language":"","subjects":["Medical physics. Medical radiology. Nuclear medicine","Radioactivity and radioactive substances"],"doi":"10.15392/bjrs.v9i1A.1573","url":"https://bjrs.org.br/revista/index.php/REVISTA/article/view/1573","is_open_access":true,"published_at":"","score":65},{"id":"doaj_10.15392/bjrs.v8i3B.685","title":"CFD Analysis of the VHTR Prismatic Core with Variation of Geometry Parameters","authors":[{"name":"Carlos Alberto Brayner Oliveira Lira"},{"name":"Pedro Paulo Dantas Souza Paiva"}],"abstract":"The Very High Temperature Reactor is a thermal, graphite moderated and helium cooled nuclear reactor. The purpose of this work is to study the behavior of the VHTR by means of parametric analysis, altering the energy generation profile in the fuel blocks and the influence of modifications in the geometry itself. The coolant flow through the coolant channels and by-pass channels were analyzed in a 1/12th section of a fuel block column. Geometry was used with by-pass channels of different dimensions, besides one that had only the cooling channels, without by-pass channel. It has been found that the existence of a by-pass flow induces an increase in the temperature gradient in the fuel block. Comparative studies were performed between the results obtained in simulations carried out with different profiles of thermal energy generation (uniform and sinusoidal) in the fuel channels. It was verified that when there is the same total thermal energy generation in the fuel block, the maximum temperature observed in each of the materials is smaller for the generation with sinusoidal profile. Computer simulations were performed using a geometry with a central channel with the same diameter as the others to verify the hypothesis that the existence of a temperature gradient in the fuel block, with the highest temperature at the center and the lowest temperature being at the periphery of this block, is due to the smaller dimension of the coolant channel located in the center of this block. The results obtained confirm the hypothesis","source":"DOAJ","year":2021,"language":"","subjects":["Medical physics. Medical radiology. Nuclear medicine","Radioactivity and radioactive substances"],"doi":"10.15392/bjrs.v8i3B.685","url":"https://bjrs.org.br/revista/index.php/REVISTA/article/view/685","is_open_access":true,"published_at":"","score":65},{"id":"ss_f9282042f0cd73a965dd4095b0ffd313e5daf4a6","title":"Modelling of hydrodynamic and solute transport with consideration of the release of low-level radioactive substances","authors":[{"name":"Roman Winter"},{"name":"B. Flemisch"},{"name":"H. Class"},{"name":"R. Merk"}],"abstract":"Abstract. When nuclear power plants are dismantled, only a small portion is heavily contaminated with radioactivity and must be stored in a repository. The remaining material, mainly concrete rubble (construction waste), is decontaminated if necessary and can be stored in conventional surface landfills after clearance. The focus of this work is on the modelling of such landfills and the radioactive substances during raining events. The influence of the heterogeneous nature of the construction rubble should also be investigated. The simulation environment DuMux, mainly developed by our institute, is used to compare different modelling approaches. It follows a previous work by Merk (2012). The research work is supported and accompanied by the Federal Office for Radiation Protection (BfS). Parts of the research initiatives of the BfS in the area of clearance of materials with negligible radioactivity are also presented.","source":"Semantic Scholar","year":2021,"language":"en","subjects":null,"doi":"10.5194/sand-1-31-2021","url":"https://www.semanticscholar.org/paper/f9282042f0cd73a965dd4095b0ffd313e5daf4a6","pdf_url":"https://sand.copernicus.org/articles/1/31/2021/sand-1-31-2021.pdf","is_open_access":true,"published_at":"","score":65},{"id":"ss_955216516857b77b8f248978ec091b6017befc8a","title":"Types of Radioactive Substances","authors":[{"name":"Dirk Eidemüller"}],"abstract":"","source":"Semantic Scholar","year":2021,"language":"en","subjects":["Environmental Science"],"doi":"10.1007/978-3-030-72670-6_4","url":"https://www.semanticscholar.org/paper/955216516857b77b8f248978ec091b6017befc8a","is_open_access":true,"published_at":"","score":65},{"id":"ss_cad088ffacaa7d9e3b4abea77da40890ceff982b","title":"Reduction of the radiation in radioactive substances","authors":[{"name":"G. Albertini"},{"name":"F. Cardone"},{"name":"G. Cherubini"},{"name":"E. Guerriero"},{"name":"A. Rosada"}],"abstract":"The radioactivity reduction of a system containing Ni-63 radioactive nuclei after an appropriate ultrasound treatment in an apparatus designed on purpose is reported. The application of ultrasounds for 200 s resulted in the partial disappearance of about 13% of the radioactive Ni-63 nuclei and the appearance of nonradioactive elements. The formation of new elements, not belonging to the decay chain of Nickel-63, is a strong issue where strong nuclear reactions transform Nickel into different elements rather than the usual weak interaction, responsible for the decay, which is accelerated. This way, the time necessary to halve the intensity is shortened by about 20 years, without altering the Ni-63 decay constant, which is [Formula: see text] years. Two cases producing similar effects in other radioactive systems after ultrasound treatment are described in the literature and support this finding, which is not forecast by the commonly accepted theories. A theory able to explain these and other results is also reported.","source":"Semantic Scholar","year":2020,"language":"en","subjects":["Materials Science"],"doi":"10.1142/s0217979220500010","url":"https://www.semanticscholar.org/paper/cad088ffacaa7d9e3b4abea77da40890ceff982b","is_open_access":true,"citations":3,"published_at":"","score":64.09}],"total":158240,"page":1,"page_size":20,"sources":["DOAJ","CrossRef","Semantic Scholar"],"query":"Radioactivity and radioactive substances"}