Pub Date : 2024-05-17DOI: 10.15392/2319-0612.2024.2361
Rodrigo Zanette, Liliane Basso Barichello, Claudio Zen Petersen
In this paper, a comparative analysis of numerical results of the neutron transport and diffusion theories for steady-state and transient multigroup problems is presented. The neutron transport equation is known as the one that best describes the behavior of the neutron population in a nuclear reactor. However, due to the difficulty of working with its complete form, other models are considered as approximations to this equation. One such approximation is the neutron diffusion equation, which uses the Fick's Law. It is well known, however, that the diffusion model may not work well under specific conditions. The objective of this work is to establish a quantitative comparison of numerical results obtained for the K dominant eigenvalue and for the scalar fluxes from the two theories and to analyze the influence of the model on the results.
本文对稳态和瞬态多组问题的中子输运和扩散理论的数值结果进行了比较分析。众所周知，中子输运方程是最能描述核反应堆中子群行为的方程。然而，由于难以使用其完整形式，人们考虑将其他模型作为该方程的近似值。其中一个近似模型是使用菲克定律的中子扩散方程。然而，众所周知，扩散模型在特定条件下可能无法很好地发挥作用。这项工作的目的是对 K 主导特征值和两种理论得出的标量通量的数值结果进行定量比较，并分析模型对结果的影响。
{"title":"A numerical validation between the neutron transport and diffusion theories for a spatial kinetics problem","authors":"Rodrigo Zanette, Liliane Basso Barichello, Claudio Zen Petersen","doi":"10.15392/2319-0612.2024.2361","DOIUrl":"https://doi.org/10.15392/2319-0612.2024.2361","url":null,"abstract":"In this paper, a comparative analysis of numerical results of the neutron transport and diffusion theories for steady-state and transient multigroup problems is presented. The neutron transport equation is known as the one that best describes the behavior of the neutron population in a nuclear reactor. However, due to the difficulty of working with its complete form, other models are considered as approximations to this equation. One such approximation is the neutron diffusion equation, which uses the Fick's Law. It is well known, however, that the diffusion model may not work well under specific conditions. The objective of this work is to establish a quantitative comparison of numerical results obtained for the K dominant eigenvalue and for the scalar fluxes from the two theories and to analyze the influence of the model on the results.","PeriodicalId":505520,"journal":{"name":"Brazilian Journal of Radiation Sciences","volume":"86 19","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140964317","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-10DOI: 10.15392/2319-0612.2024.2418
Natasha Briggs, Andrea Mantuano Coelho da Silva, Arissa Pickler Oliveira, Domingos Cardoso D'Oliveira, Aneuri Souza de Amorim
The IDQBRN/CTEx has a Cs-137 research irradiator whose prupose is to promove the development of research in the area of irradiation of materials, assisting in the acquisition of data and scientific publications in the area. Because it is used for research, it is necessary to verify the distribution of dose point in the irradiator chambers. The purpose of this work is to carry out a five-point dosimetry of each irradiator chamber, using the Fricke chemical dosimeter. This dosimeter is used worldwide in several areas of medical and industrial physics, presenting relevant characteristics such as low cost, uncertainties of less than 3% in industrial applications, in addition to being an absolute and primary dosimeter. Dosimetry was performed in the IDQBRN/CTEx irradiator drawers where the materials to be irradiated are placed in the research irradiator chamber.
{"title":"Determinação da Dose Absorvida na Água em Câmaras de irradiador de pesquisa de Cs-137 utilizando o Dosímetro Fricke","authors":"Natasha Briggs, Andrea Mantuano Coelho da Silva, Arissa Pickler Oliveira, Domingos Cardoso D'Oliveira, Aneuri Souza de Amorim","doi":"10.15392/2319-0612.2024.2418","DOIUrl":"https://doi.org/10.15392/2319-0612.2024.2418","url":null,"abstract":"The IDQBRN/CTEx has a Cs-137 research irradiator whose prupose is to promove the development of research in the area of irradiation of materials, assisting in the acquisition of data and scientific publications in the area. Because it is used for research, it is necessary to verify the distribution of dose point in the irradiator chambers. The purpose of this work is to carry out a five-point dosimetry of each irradiator chamber, using the Fricke chemical dosimeter. This dosimeter is used worldwide in several areas of medical and industrial physics, presenting relevant characteristics such as low cost, uncertainties of less than 3% in industrial applications, in addition to being an absolute and primary dosimeter. Dosimetry was performed in the IDQBRN/CTEx irradiator drawers where the materials to be irradiated are placed in the research irradiator chamber.","PeriodicalId":505520,"journal":{"name":"Brazilian Journal of Radiation Sciences","volume":" 33","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140994093","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-03DOI: 10.15392/2319-0612.2024.2405
Francky Roger Araujo da Silva, Giovanni Laranjo de Stefani, Marcelo Vilela da Silva
This article analyzes the SWOT Matrix for the implementation of the AP-Th1000 reactor with thorium fuel, aiming at a future replacement of the current nuclear reactors that use uranium as fuel by thorium. There was a need for an in-depth study of the national and international literature linked to the Brazilian reality. After that, specific meetings were held to detect all possible situations of the 4 main points of the SWOT matrix. During the sessions, which averaged 1 hour, the authors' industrial and academic expertise was demonstrated in competencies such as creativity, collaboration, effective communication, openness and tolerance, quick thinking, synthesis ability, problem focus, and flexibility during the discussions of over 50 items found in the analysis of the 4 points of the SWOT matrix. Each meeting was divided into three parts. The first part, which would be the Creative phase; and a second part, which would be the Critical phase; and, finally, the third phase, where ideas are filtered for the permanence of those that were better founded and of better acceptance. Then, the aspects listed were classified into 4 categories: Strengths (S), Weaknesses (W), Opportunities (O), and Threats (T). After the classification, a ranking of priorities was made, in descending order of importance, according to the authors, of the weaknesses and threats, neutralization suggestions were made. Finally, the data obtained were analyzed. We concluded through the SWOT analysis, we can observe an expressive amount of benefits of using the AP1000 reactor with MOX of Thorium and Uranium in the development of nuclear energy generation technologies in Brazil.
{"title":"Analysis of the SWOT matrix as a strategy for implementing the Ap-Th1000 Reactor in Brazil","authors":"Francky Roger Araujo da Silva, Giovanni Laranjo de Stefani, Marcelo Vilela da Silva","doi":"10.15392/2319-0612.2024.2405","DOIUrl":"https://doi.org/10.15392/2319-0612.2024.2405","url":null,"abstract":"This article analyzes the SWOT Matrix for the implementation of the AP-Th1000 reactor with thorium fuel, aiming at a future replacement of the current nuclear reactors that use uranium as fuel by thorium. There was a need for an in-depth study of the national and international literature linked to the Brazilian reality. After that, specific meetings were held to detect all possible situations of the 4 main points of the SWOT matrix. During the sessions, which averaged 1 hour, the authors' industrial and academic expertise was demonstrated in competencies such as creativity, collaboration, effective communication, openness and tolerance, quick thinking, synthesis ability, problem focus, and flexibility during the discussions of over 50 items found in the analysis of the 4 points of the SWOT matrix. Each meeting was divided into three parts. The first part, which would be the Creative phase; and a second part, which would be the Critical phase; and, finally, the third phase, where ideas are filtered for the permanence of those that were better founded and of better acceptance. Then, the aspects listed were classified into 4 categories: Strengths (S), Weaknesses (W), Opportunities (O), and Threats (T). After the classification, a ranking of priorities was made, in descending order of importance, according to the authors, of the weaknesses and threats, neutralization suggestions were made. Finally, the data obtained were analyzed. We concluded through the SWOT analysis, we can observe an expressive amount of benefits of using the AP1000 reactor with MOX of Thorium and Uranium in the development of nuclear energy generation technologies in Brazil.","PeriodicalId":505520,"journal":{"name":"Brazilian Journal of Radiation Sciences","volume":"135 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141015247","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-24DOI: 10.15392/2319-0612.2024.2404
Victoria M. Garcia, A. C. M. Silva, R. Gontijo, Andréa Vidal Ferreira
Nuclear Medicine is a modality that has been growing a lot in Brazil and in the world, bringing new radiopharmaceuticals and technologies for the diagnosis and treatment of diseases, making them more effective and accurate. In the development of new radiopharmaceuticals for use in positron emission tomography (PET), the preclinical studies step largely uses PET scanners dedicated to small animals. To achieve this, quality control tests must be carried out to ensure the efficiency of the equipment. Thus, this work aimed to evaluate the spatial resolution of the small animals PET scanner of the CDTN using the isotope 68Ga. In this sense, a microPET hot rod phantom and a commercial 68Ge/68Ga generator were used to obtain PET images. The analysis of the 68Ga-PET images of the simulator was carried out qualitatively and quantitatively and revealed that the spatial resolution of the system using the 68Ga is 3.5 mm.
核医学是一种在巴西和世界范围内发展迅速的医学模式，它为疾病的诊断和治疗带来了新的放射性药物和技术，使诊断和治疗更加有效和准确。在开发用于正电子发射断层扫描（PET）的新型放射性药物时，临床前研究步骤主要使用小动物专用 PET 扫描仪。为此，必须进行质量控制测试，以确保设备的效率。因此，这项工作旨在评估 CDTN 小型动物 PET 扫描仪使用同位素 68Ga 的空间分辨率。为此，使用了微型 PET 热棒模型和商用 68Ge/68Ga 发生器来获取 PET 图像。对模拟器的 68Ga-PET 图像进行了定性和定量分析，结果显示，使用 68Ga 的系统的空间分辨率为 3.5 毫米。
{"title":"Resolução espacial de um tomógrafo PET de pequenos animais usando o isótopo 68Ga","authors":"Victoria M. Garcia, A. C. M. Silva, R. Gontijo, Andréa Vidal Ferreira","doi":"10.15392/2319-0612.2024.2404","DOIUrl":"https://doi.org/10.15392/2319-0612.2024.2404","url":null,"abstract":"Nuclear Medicine is a modality that has been growing a lot in Brazil and in the world, bringing new radiopharmaceuticals and technologies for the diagnosis and treatment of diseases, making them more effective and accurate. In the development of new radiopharmaceuticals for use in positron emission tomography (PET), the preclinical studies step largely uses PET scanners dedicated to small animals. To achieve this, quality control tests must be carried out to ensure the efficiency of the equipment. Thus, this work aimed to evaluate the spatial resolution of the small animals PET scanner of the CDTN using the isotope 68Ga. In this sense, a microPET hot rod phantom and a commercial 68Ge/68Ga generator were used to obtain PET images. The analysis of the 68Ga-PET images of the simulator was carried out qualitatively and quantitatively and revealed that the spatial resolution of the system using the 68Ga is 3.5 mm.","PeriodicalId":505520,"journal":{"name":"Brazilian Journal of Radiation Sciences","volume":"44 8","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140662383","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-17DOI: 10.15392/2319-0612.2024.2352
Guilherme Rodrigues, Ariane Campolim Cristino, Daniela R. Cantane, H. O. Florentino, Marco A. R. Fernandes, Paulo E. M. Ribolla, Rogerio A. Oliveira
Aedes aegypti mosquito, popularly known as the dengue mosquito, represents a serious public health problem, because it is the vector responsible for several serious diseases such as Chikungunya fever, Zika virus and Dengue, the latter of which has a higher incidence in the Brazilian population. That mosquito has a high capacity for adaptation in the most diverse types of environments, mainly in places with high population density and lack of basic sanitation, factors that favor its proliferation. The control methods used by the epidemiological surveillance agencies are divided into three modalities: mechanical control, chemical control and biological control. Among the biological control methods, the Sterile Insect Technique (SIT) technique stands out, which consists of introducing sterile males into the mosquito population. This article presents reproduction analyzes of a population of natural mosquitoes compared to a population of mosquitoes with the insertion of males sterilized by ionizing radiation, seeking to observe the impact caused by this control method. The statistical analyzes showed the Negative Binomial regression model presented a better fit to the daily egg count data, when this model was compared to the Poisson model. In addition, the introduction of irradiated males decreases the average oviposition rate by approximately 30%.
{"title":"Generalized linear models applied to the analysis of the effectiveness of the Sterile Insect Technique","authors":"Guilherme Rodrigues, Ariane Campolim Cristino, Daniela R. Cantane, H. O. Florentino, Marco A. R. Fernandes, Paulo E. M. Ribolla, Rogerio A. Oliveira","doi":"10.15392/2319-0612.2024.2352","DOIUrl":"https://doi.org/10.15392/2319-0612.2024.2352","url":null,"abstract":"Aedes aegypti mosquito, popularly known as the dengue mosquito, represents a serious public health problem, because it is the vector responsible for several serious diseases such as Chikungunya fever, Zika virus and Dengue, the latter of which has a higher incidence in the Brazilian population. That mosquito has a high capacity for adaptation in the most diverse types of environments, mainly in places with high population density and lack of basic sanitation, factors that favor its proliferation. The control methods used by the epidemiological surveillance agencies are divided into three modalities: mechanical control, chemical control and biological control. Among the biological control methods, the Sterile Insect Technique (SIT) technique stands out, which consists of introducing sterile males into the mosquito population. This article presents reproduction analyzes of a population of natural mosquitoes compared to a population of mosquitoes with the insertion of males sterilized by ionizing radiation, seeking to observe the impact caused by this control method. The statistical analyzes showed the Negative Binomial regression model presented a better fit to the daily egg count data, when this model was compared to the Poisson model. In addition, the introduction of irradiated males decreases the average oviposition rate by approximately 30%.","PeriodicalId":505520,"journal":{"name":"Brazilian Journal of Radiation Sciences","volume":" 6","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140691763","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-17DOI: 10.15392/2319-0612.2023.2201
Gustavo BERNARDES DA SILVA, Viviane RODRIGUES BOTELHO, Carla Diniz Lopes Becker, Cassiana Viccari, Thatiane A. Pianoschi
Attenuation coefficients are essential physical parameters for many applications, such as the calculation of photon penetration and energy deposition to evaluate biological shielding. Estimating these parameters is complex, making it necessary to apply more sophisticated methodologies. The objective of the present study was to propose a model for estimating the attenuation coefficients using artificial neural networks. The NIST database was used to estimate the attenuation coefficients in terms of energy and atomic number from a regression problem using two approaches: the proposition of an automated model using the framework Talos and a manual model using Keras. The characteristics of the best model proposed in Talos were applied in manual training via Keras with cross-validation to evaluate the learning curves. The following were also assessed: the comparison of the curves of the attenuation coefficients predicted by the model compared with the reference data and the general comparison of the vectors X and y of the two models discussed. The Talos framework reference model obtained the following values of Loss and MSE error metric: 0.13 and 0.037, respectively. The best model of the manual approach received the following results: 0.19 and 0.08 for the loss function and MSE error metric, respectively. The absolute percentage error (MAE) of the difference in the results between the two models was: 0.065 and 0.044 for the Loss and MSE metrics. Despite applying two distinct propositions, both models had the same difficulties in predicting discontinuities in the physical behavior associated with the attenuation coefficients.
衰减系数是许多应用中的基本物理参数，例如计算光子穿透和能量沉积以评估生物屏蔽。估算这些参数非常复杂，因此有必要采用更复杂的方法。本研究的目的是提出一种利用人工神经网络估算衰减系数的模型。研究人员使用 NIST 数据库，通过两种方法从回归问题中估算出能量和原子序数方面的衰减系数：一种是使用 Talos 框架提出自动模型，另一种是使用 Keras 提出人工模型。Talos 中提出的最佳模型的特征被应用于通过 Keras 进行交叉验证的手动训练，以评估学习曲线。此外，还对以下方面进行了评估：模型预测的衰减系数曲线与参考数据的比较，以及两个模型的向量 X 和 y 的总体比较。Talos 框架参考模型的损失和 MSE 误差指标值分别为 0.13 和 0.037。人工方法的最佳模型得到了以下结果：损失函数和 MSE 误差指标分别为 0.19 和 0.08。两个模型结果差异的绝对百分比误差（MAE）分别为：损失和 MSE 指标分别为 0.065 和 0.044。尽管采用了两种不同的命题，但这两种模型在预测与衰减系数相关的物理行为的不连续性时都遇到了同样的困难。
{"title":"Modeling of the mass attenuation coefficients of X ray beams using deep neural networks (DNN) and NIST database","authors":"Gustavo BERNARDES DA SILVA, Viviane RODRIGUES BOTELHO, Carla Diniz Lopes Becker, Cassiana Viccari, Thatiane A. Pianoschi","doi":"10.15392/2319-0612.2023.2201","DOIUrl":"https://doi.org/10.15392/2319-0612.2023.2201","url":null,"abstract":"Attenuation coefficients are essential physical parameters for many applications, such as the calculation of photon penetration and energy deposition to evaluate biological shielding. Estimating these parameters is complex, making it necessary to apply more sophisticated methodologies. The objective of the present study was to propose a model for estimating the attenuation coefficients using artificial neural networks. The NIST database was used to estimate the attenuation coefficients in terms of energy and atomic number from a regression problem using two approaches: the proposition of an automated model using the framework Talos and a manual model using Keras. The characteristics of the best model proposed in Talos were applied in manual training via Keras with cross-validation to evaluate the learning curves. The following were also assessed: the comparison of the curves of the attenuation coefficients predicted by the model compared with the reference data and the general comparison of the vectors X and y of the two models discussed. The Talos framework reference model obtained the following values of Loss and MSE error metric: 0.13 and 0.037, respectively. The best model of the manual approach received the following results: 0.19 and 0.08 for the loss function and MSE error metric, respectively. The absolute percentage error (MAE) of the difference in the results between the two models was: 0.065 and 0.044 for the Loss and MSE metrics. Despite applying two distinct propositions, both models had the same difficulties in predicting discontinuities in the physical behavior associated with the attenuation coefficients.","PeriodicalId":505520,"journal":{"name":"Brazilian Journal of Radiation Sciences","volume":"24 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140693831","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-12DOI: 10.15392/2319-0612.2023.2177
Ana Luísa Da Costa Vieira, Fernanda Do Nacimento Moura
This work is about radiation protection training at Sirius, a unique radiation facility in Brazil for being a synchrotron-type particle accelerator. Research in several areas takes place at the facility, attracting researchers from all over the world. The radiological protection group at Sirius works continuously to ensure everyone's safety, in addition to shielding and monitoring, there are several security elements and one of them is the application of radiological safety training, where the researcher is presented the “Search” procedure. At the end of the training, the researcher answers a feedback form, which is used as a satisfaction survey. In the first semester for 2022, 46 people were trained of which 43.47% responded to the feedback form. Of the total responses, 95% were satisfied. Due to the large number of people attending Sirius, the radiation safety training is in the process of moving to an online format, which brings new challenges.
{"title":"Enhancing radiation protection at Sirius: methodology and results of beamline training","authors":"Ana Luísa Da Costa Vieira, Fernanda Do Nacimento Moura","doi":"10.15392/2319-0612.2023.2177","DOIUrl":"https://doi.org/10.15392/2319-0612.2023.2177","url":null,"abstract":"This work is about radiation protection training at Sirius, a unique radiation facility in Brazil for being a synchrotron-type particle accelerator. Research in several areas takes place at the facility, attracting researchers from all over the world. The radiological protection group at Sirius works continuously to ensure everyone's safety, in addition to shielding and monitoring, there are several security elements and one of them is the application of radiological safety training, where the researcher is presented the “Search” procedure. At the end of the training, the researcher answers a feedback form, which is used as a satisfaction survey. In the first semester for 2022, 46 people were trained of which 43.47% responded to the feedback form. Of the total responses, 95% were satisfied. Due to the large number of people attending Sirius, the radiation safety training is in the process of moving to an online format, which brings new challenges.","PeriodicalId":505520,"journal":{"name":"Brazilian Journal of Radiation Sciences","volume":"1 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140710657","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-10DOI: 10.15392/2319-0612.2024.2359
M. R. Gual, Marcos Coelho Maturana, Nathalia Nunes Araújo, Marcelo Ramos Martins
During the Fukushima Daiichi nuclear accident in 2011, hydrogen explosions occurred in all units from Unit 1 to Unit 3. Consequently, one of the lessons learned from the Fukushima Daiichi accident is the necessity of implementing hydrogen control and mitigation strategies for most Nuclear Power Plants (NPPs). This paper focuses on the incorporation of Passive Autocatalytic Recombiners (PARs) during the design phase of a small modular Pressurized Water Reactor (SMR-PWR) project. The numerical analyses are conducted using the MELCOR v. 2.2 code. Two scenarios are compared: the Total Loss of Feed Water (TLOFW) severe accident with and without PARs. Saphiro’s diagram is utilized to investigate whether the mixture's composition (hydrogen, air, steam) is flammable for both scenarios. It has been observed that the inclusion of PARs leads to a reduction in hydrogen risk (detonative or deflagrative) as the final hydrogen concentration values fall below the flammability limit. This study is preliminary, and further research is required.
在 2011 年福岛第一核电站事故中，从 1 号机组到 3 号机组的所有机组都发生了氢气爆炸。因此，从福岛第一核电站事故中吸取的教训之一是，大多数核电站都必须实施氢控制和缓解策略。本文的重点是在小型模块化压水堆（SMR-PWR）项目的设计阶段纳入被动式自催化重组器（PAR）。数值分析使用 MELCOR v. 2.2 代码进行。比较了两种情况：有 PAR 和无 PAR 的给水全损 (TLOFW) 严重事故。利用 Saphiro 图来研究两种情况下的混合物成分（氢气、空气、蒸汽）是否易燃。研究发现，由于最终的氢浓度值低于可燃性极限，加入 PARs 会降低氢气风险（引爆或爆燃）。这项研究是初步的，还需要进一步研究。
{"title":"Analysis of hydrogen control in a Small Modular Reactor during TLOFW severe accident","authors":"M. R. Gual, Marcos Coelho Maturana, Nathalia Nunes Araújo, Marcelo Ramos Martins","doi":"10.15392/2319-0612.2024.2359","DOIUrl":"https://doi.org/10.15392/2319-0612.2024.2359","url":null,"abstract":"During the Fukushima Daiichi nuclear accident in 2011, hydrogen explosions occurred in all units from Unit 1 to Unit 3. Consequently, one of the lessons learned from the Fukushima Daiichi accident is the necessity of implementing hydrogen control and mitigation strategies for most Nuclear Power Plants (NPPs). This paper focuses on the incorporation of Passive Autocatalytic Recombiners (PARs) during the design phase of a small modular Pressurized Water Reactor (SMR-PWR) project. The numerical analyses are conducted using the MELCOR v. 2.2 code. Two scenarios are compared: the Total Loss of Feed Water (TLOFW) severe accident with and without PARs. Saphiro’s diagram is utilized to investigate whether the mixture's composition (hydrogen, air, steam) is flammable for both scenarios. It has been observed that the inclusion of PARs leads to a reduction in hydrogen risk (detonative or deflagrative) as the final hydrogen concentration values fall below the flammability limit. This study is preliminary, and further research is required. ","PeriodicalId":505520,"journal":{"name":"Brazilian Journal of Radiation Sciences","volume":"2020 26","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140718250","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-03DOI: 10.15392/2319-0612.2024.2356
A. G. N. Santo, A. A. Mol, D. M. Machado, E. R. Marins
In recent years, the importance of improving physical protection in nuclear facilities has been observed, mainly due to the increasing progress of the Brazilian nuclear program. Physical protection requires great attention and strategies that must be designed, tested and improved in order to maintain the physical integrity of the facilities and population. These strategies should be tested in exercises to see if the physical protection plan - PPP is in accordance with the actual conditions of the facility, such as: visibility of the borders and terrain, number and equipment of the team in charge of defense (security guards), detection equipment and access times of central security point agents to the places where suspicious activities have been detected. In this sense, this article aimed to develop a tool that allow the visualization and planning of action strategies in a virtual environment, aiming to improve security. A virtual model of the Instituto de Engenharia Nuclear (IEN) was created, with close representations of reality and the virtual characters can transit and interact in real time. Various situations that affect the visibility and detection of opponents, such as natural and artificial lighting, climatic phenomena, shadows and others can be simulated with a high degree of realism. In addition, the tool has a surveillance system through virtual cameras, enabling monitoring of the environment. Thus, this system will allow to simulate approach strategies, allowing an evaluation of the procedures performed, as well as assist in physical protection training in radioactive and nuclear facilities.
{"title":"O uso da realidade virtual no desenvolvimento de um sistema colaborativo para simulação de segurança física em instalações nucleares","authors":"A. G. N. Santo, A. A. Mol, D. M. Machado, E. R. Marins","doi":"10.15392/2319-0612.2024.2356","DOIUrl":"https://doi.org/10.15392/2319-0612.2024.2356","url":null,"abstract":"In recent years, the importance of improving physical protection in nuclear facilities has been observed, mainly due to the increasing progress of the Brazilian nuclear program. Physical protection requires great attention and strategies that must be designed, tested and improved in order to maintain the physical integrity of the facilities and population. These strategies should be tested in exercises to see if the physical protection plan - PPP is in accordance with the actual conditions of the facility, such as: visibility of the borders and terrain, number and equipment of the team in charge of defense (security guards), detection equipment and access times of central security point agents to the places where suspicious activities have been detected. In this sense, this article aimed to develop a tool that allow the visualization and planning of action strategies in a virtual environment, aiming to improve security. A virtual model of the Instituto de Engenharia Nuclear (IEN) was created, with close representations of reality and the virtual characters can transit and interact in real time. Various situations that affect the visibility and detection of opponents, such as natural and artificial lighting, climatic phenomena, shadows and others can be simulated with a high degree of realism. In addition, the tool has a surveillance system through virtual cameras, enabling monitoring of the environment. Thus, this system will allow to simulate approach strategies, allowing an evaluation of the procedures performed, as well as assist in physical protection training in radioactive and nuclear facilities.","PeriodicalId":505520,"journal":{"name":"Brazilian Journal of Radiation Sciences","volume":"250 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140746079","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-27DOI: 10.15392/2319-0612.2024.2387
Carlo Method Haubrich, O. Medeiros, M. P. C. D’Oliveira, Monte Carlo
To evaluate the efficiency of neutron capture therapy (BNCT) treatment in glioblastoma multiforme, it is necessary to evaluate the impact of the neutron beam on the tumor cell and find better results so that BNCT treatment is viable. Glioblastoma multiforme is one of the most lethal cancers and conventional radiotherapy is almost ineffective for this type of tumor. Among several approaches to describe the procedure and the neutron spectrum, the Maxwell spectrum in the epithermal neutron range was used. For this, T=0.0025 MeV was used to describe this spectrum. MCNP software was used to simulate a BNCT treatment using the Maxwell spectrum to describe the neutron source. The user provided the quantities of interest, such as fluence and dose. These are extremely important quantities to describe a BNCT planning protocol. A concentration of 30 ppm of Boron-10 was simulated in the tumor. Output data provides normalized values. It was necessary to carry out some mathematical operations to obtain values closer to reality. Thus, a dose of 32 Gy was obtained for the Maxwell spectrum described with T=0.0025 MeV and a neutron fluence of 1.5 x 1012 n/cm². The values calculated based on the simulation in MCNP5 described by an epithermal neutron source obeying a Maxwellian function, were in agreement with the reference values in the literature.
{"title":"Maxwell Spectrum as a Parameter to Verify the Dose in Brain Cancer (Glioblastoma) by Boron Neutron Capture Therapy (BNCT) using Monte Carlo Method","authors":"Carlo Method Haubrich, O. Medeiros, M. P. C. D’Oliveira, Monte Carlo","doi":"10.15392/2319-0612.2024.2387","DOIUrl":"https://doi.org/10.15392/2319-0612.2024.2387","url":null,"abstract":"To evaluate the efficiency of neutron capture therapy (BNCT) treatment in glioblastoma multiforme, it is necessary to evaluate the impact of the neutron beam on the tumor cell and find better results so that BNCT treatment is viable. Glioblastoma multiforme is one of the most lethal cancers and conventional radiotherapy is almost ineffective for this type of tumor. Among several approaches to describe the procedure and the neutron spectrum, the Maxwell spectrum in the epithermal neutron range was used. For this, T=0.0025 MeV was used to describe this spectrum. MCNP software was used to simulate a BNCT treatment using the Maxwell spectrum to describe the neutron source. The user provided the quantities of interest, such as fluence and dose. These are extremely important quantities to describe a BNCT planning protocol. A concentration of 30 ppm of Boron-10 was simulated in the tumor. Output data provides normalized values. It was necessary to carry out some mathematical operations to obtain values closer to reality. Thus, a dose of 32 Gy was obtained for the Maxwell spectrum described with T=0.0025 MeV and a neutron fluence of 1.5 x 1012 n/cm². The values calculated based on the simulation in MCNP5 described by an epithermal neutron source obeying a Maxwellian function, were in agreement with the reference values in the literature.","PeriodicalId":505520,"journal":{"name":"Brazilian Journal of Radiation Sciences","volume":"8 24","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140374874","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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