Pub Date : 2023-10-15DOI: 10.15392/2319-0612.2023.2216
Angela Souza Gonçalves, Fellipe Souza da Silva, Evaldo Simões da Fonseca, Karla Cristina de Souza Patrão, Walsan Wagner Pereira
The new edition of ISO 8529 series reduced from 4 to 3 standard neutron reference field. Recent studies have highlighted the increasing importance of characterizing neutron source spectra at different energies to obtain appropriate fluence-to-dose-equivalent conversion coefficient. This study presents the determination of neutron energy fluency from a free and moderated 252Cf (120 µg) source placed within spheres of different diameters containing distilled water. The spectrum determination is based on both Monte Carlo simulations and experimental measurements with Bonner Sphere Spectrometer (BSS) of multiple diameters: 5.08 cm (2"), 7.62 cm (3”), 12.70 cm (5”), 20.32 cm (8”), 25.40 cm (10”), and 30.48 cm (12”). The aim was to characterize the new water-moderated spectra, obtaining reference values for operational quantities that represent realistic radiation fields for testing, calibrating, and irradiation of personal dosimetry and survey meters.
{"title":"A feasibility study of a H2O-moderated 252Cf source for metrology","authors":"Angela Souza Gonçalves, Fellipe Souza da Silva, Evaldo Simões da Fonseca, Karla Cristina de Souza Patrão, Walsan Wagner Pereira","doi":"10.15392/2319-0612.2023.2216","DOIUrl":"https://doi.org/10.15392/2319-0612.2023.2216","url":null,"abstract":"The new edition of ISO 8529 series reduced from 4 to 3 standard neutron reference field. Recent studies have highlighted the increasing importance of characterizing neutron source spectra at different energies to obtain appropriate fluence-to-dose-equivalent conversion coefficient. This study presents the determination of neutron energy fluency from a free and moderated 252Cf (120 µg) source placed within spheres of different diameters containing distilled water. The spectrum determination is based on both Monte Carlo simulations and experimental measurements with Bonner Sphere Spectrometer (BSS) of multiple diameters: 5.08 cm (2\"), 7.62 cm (3”), 12.70 cm (5”), 20.32 cm (8”), 25.40 cm (10”), and 30.48 cm (12”). The aim was to characterize the new water-moderated spectra, obtaining reference values for operational quantities that represent realistic radiation fields for testing, calibrating, and irradiation of personal dosimetry and survey meters.","PeriodicalId":9203,"journal":{"name":"Brazilian Journal of Radiation Sciences","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136185224","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 : 2023-10-09DOI: 10.15392/2319-0612.2023.2157
José Wilson Vieira, Viriato Leal Neto, None Pedro Henrique Avelino de Andrade, None Alex Cristóvão Holanda de Oliveira, None Vanildo Júnior de Melo Lima, None Isabelle Viviane Batista de Lacerda, None Luís Rodrigo Dandrada, None Arykerne Nascimento Casado da Silva, None William de Souza Santos, None Ivan Eufrázio de Santana, None Whoody Alem Wanderley Araripe Farias, None Larissa Cristina Silva dos Santos, None Fernanda Gonçalves Oliveira, None Fernando Roberto de Andrade Lima
In computational dosimetry of ionizing radiation, the energy deposited in radiosensitive organs and tissues is evaluated when an anthropomorphic simulator (phantom) is irradiated using Exposure Computational Models (ECMs). An ECM is a virtual scene with a phantom positioned mathematically relative to a radioactive source. The initial state includes information like the type of primary particle, its energy, starting point coordinates, and direction. Subsequently, robust Monte Carlo (MC) codes are used to simulate the particle's mean free path, interaction with the medium's atoms, and energy deposition. These are common steps for simulations involving photons and/or primary electrons. The GDN (Research Group on Numerical Dosimetry and the Research Group on Computational Dosimetry and Embedded Systems) has published ECMs with voxel phantoms irradiated by photons using the MC code EGSnrc. This work has led to specific computational tools development for various numerical dosimetry stages, including input file preparation, ECM execution, and result analysis. Since 2004, the GDN developed in-house applications like FANTOMAS, CALDose_X, DIP, and MonteCarlo. Certain previously used phantoms are reintroduced to provide historical context in the ECMs' production timeline, emphasizing additive modifications inherent in systematic theme studies. The dosimetric evaluations used the binary version of the MASH (Male Adult mesh) phantom, converted to the SID (Dosimetric Information System) text file type. This format has been used by the group since 2021 to couple a voxel phantom to the EGSnrc user code. The ECM included an environmental dosimetry problem simulation. Most of these tools are accessible on the GDN page (http://dosimetrianumerica.org).
{"title":"Exposure computational models with voxel phantoms coupled to EGSnrc Monte Carlo code","authors":"José Wilson Vieira, Viriato Leal Neto, None Pedro Henrique Avelino de Andrade, None Alex Cristóvão Holanda de Oliveira, None Vanildo Júnior de Melo Lima, None Isabelle Viviane Batista de Lacerda, None Luís Rodrigo Dandrada, None Arykerne Nascimento Casado da Silva, None William de Souza Santos, None Ivan Eufrázio de Santana, None Whoody Alem Wanderley Araripe Farias, None Larissa Cristina Silva dos Santos, None Fernanda Gonçalves Oliveira, None Fernando Roberto de Andrade Lima","doi":"10.15392/2319-0612.2023.2157","DOIUrl":"https://doi.org/10.15392/2319-0612.2023.2157","url":null,"abstract":"In computational dosimetry of ionizing radiation, the energy deposited in radiosensitive organs and tissues is evaluated when an anthropomorphic simulator (phantom) is irradiated using Exposure Computational Models (ECMs). An ECM is a virtual scene with a phantom positioned mathematically relative to a radioactive source. The initial state includes information like the type of primary particle, its energy, starting point coordinates, and direction. Subsequently, robust Monte Carlo (MC) codes are used to simulate the particle's mean free path, interaction with the medium's atoms, and energy deposition. These are common steps for simulations involving photons and/or primary electrons. The GDN (Research Group on Numerical Dosimetry and the Research Group on Computational Dosimetry and Embedded Systems) has published ECMs with voxel phantoms irradiated by photons using the MC code EGSnrc. This work has led to specific computational tools development for various numerical dosimetry stages, including input file preparation, ECM execution, and result analysis. Since 2004, the GDN developed in-house applications like FANTOMAS, CALDose_X, DIP, and MonteCarlo. Certain previously used phantoms are reintroduced to provide historical context in the ECMs' production timeline, emphasizing additive modifications inherent in systematic theme studies. The dosimetric evaluations used the binary version of the MASH (Male Adult mesh) phantom, converted to the SID (Dosimetric Information System) text file type. This format has been used by the group since 2021 to couple a voxel phantom to the EGSnrc user code. The ECM included an environmental dosimetry problem simulation. Most of these tools are accessible on the GDN page (http://dosimetrianumerica.org).","PeriodicalId":9203,"journal":{"name":"Brazilian Journal of Radiation Sciences","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135047630","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 : 2023-09-30DOI: 10.15392/2319-0612.2023.2300
Jousie Michel Pereira, Brígida Gomes de Almeida Schirmer, Marina Rios Araujo, Leonardo T. C. Nascimento, Andrea Vidal Ferreira, Aline de Biasi Bassani Gonçalves, Lucíola da Silva Barcelos, Geovanni Dantas Cassali, Marina Bicalho Silveira, Juliana Batista da Silva, Carlos Malamut
The use of the tracer 18F-fluoro-3'-deoxy-3'-L-fluorothymidine ([18F]FLT) in positron emission tomography (PET) has been shown to be an effective tool for assessing tumor aggressiveness and early response to therapy. In this study, we investigated the applicability of [18F]FLT/PET to study the antitumor and anti–lung metastatic effects of rosmarinic acid (RA) in highly invasive breast cancer. 4T1 mammary carcinoma cells were injected into the flank of female Balb/c mice. The animals were treated daily with RA until day 21 after the inoculation of tumor cells. [18F]FLT/PET imaging was used to evaluate the response of primary tumors and lung metastases to RA treatment. PET Images showed a decreased [18F]FLT uptake in the lungs of mice after RA treatment. The antitumor effect of RA appears to be related to the inhibition of cell migration, cell proliferation, and blood vessel formation in the primary tumor. Furthermore, the inflammatory response was modulated by RA, which reduced the accumulation of mast cells and neutrophils in the primary tumor and of macrophages in the lungs. In conclusion, [18F]FLT/PET demonstrates the antitumor and antimetastatic effects of RA in a 4T1 breast tumor model. Furthermore, the findings suggest that RA modulates tumor angiogenesis and inflammation, resulting in antitumor and antimetastatic effects in a 4T1 breast carcinoma model.
{"title":"Use of [18F]FLT/PET for assessing the tumor evolution and monitoring the antitumor activity of rosmarinic acid in a mouse 4T1 breast tumor model","authors":"Jousie Michel Pereira, Brígida Gomes de Almeida Schirmer, Marina Rios Araujo, Leonardo T. C. Nascimento, Andrea Vidal Ferreira, Aline de Biasi Bassani Gonçalves, Lucíola da Silva Barcelos, Geovanni Dantas Cassali, Marina Bicalho Silveira, Juliana Batista da Silva, Carlos Malamut","doi":"10.15392/2319-0612.2023.2300","DOIUrl":"https://doi.org/10.15392/2319-0612.2023.2300","url":null,"abstract":"The use of the tracer 18F-fluoro-3'-deoxy-3'-L-fluorothymidine ([18F]FLT) in positron emission tomography (PET) has been shown to be an effective tool for assessing tumor aggressiveness and early response to therapy. In this study, we investigated the applicability of [18F]FLT/PET to study the antitumor and anti–lung metastatic effects of rosmarinic acid (RA) in highly invasive breast cancer. 4T1 mammary carcinoma cells were injected into the flank of female Balb/c mice. The animals were treated daily with RA until day 21 after the inoculation of tumor cells. [18F]FLT/PET imaging was used to evaluate the response of primary tumors and lung metastases to RA treatment. PET Images showed a decreased [18F]FLT uptake in the lungs of mice after RA treatment. The antitumor effect of RA appears to be related to the inhibition of cell migration, cell proliferation, and blood vessel formation in the primary tumor. Furthermore, the inflammatory response was modulated by RA, which reduced the accumulation of mast cells and neutrophils in the primary tumor and of macrophages in the lungs. In conclusion, [18F]FLT/PET demonstrates the antitumor and antimetastatic effects of RA in a 4T1 breast tumor model. Furthermore, the findings suggest that RA modulates tumor angiogenesis and inflammation, resulting in antitumor and antimetastatic effects in a 4T1 breast carcinoma model.","PeriodicalId":9203,"journal":{"name":"Brazilian Journal of Radiation Sciences","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136341755","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 : 2023-09-24DOI: 10.15392/2319-0612.2023.2295
Joel Charles Garcia, Marina De Arruda Botelho, Delano Valdivino Santos Baptista, Cláudio Viegas, Saulo Santos Fortes
The objective of the TBI treatment is the ablation of the bone marrow and the destruction of the circulating leukemia cells, once they are widely distributed throughout the body. Using beam parameters acquired under conventional SSD in TBI treatments may add non-negligible uncertainties in the monitor units calculation or in the beam profiles. The study, aims to commission the 6 and 10 MV photon beams, of the Varian accelerator CX model. A slab phantom and dosimetric assembly were used under TBI conditions. The accuracy of the TPS was evaluated against the experimental data. A set of data were acquired, highlighting the TPR table and methodology for calculating MU has been implemented. The TPS has presented a statistical uncertainty of ± 2.7 % compared to the experimental data for monitor unit calculation. The use of an acrylic spoiler has been shown to be clinically advantageous where, for a 6 MV beam, the entrance PDD was 75 % without a spoiler and 99.5 % with a spoiler. For a 10 MV beam, it was verified that without a spoiler, the entrance PDD was about 55 %, but with a spoiler, it was about 93 %. For medium Heterogeneous the TPS underestimated dose values by up to - 3.5 % with a mean deviation of – 2.9 %, for 6 MV and for 10 MV, the TPS overestimated the dose values by up to 1.1 %, with an average deviation of 1.0 % using the acrylic thorax phantom. The data obtained can be used clinically.
{"title":"Commissioning of 6 and 10 MV Beams for Total Body Irradiation (TBI)","authors":"Joel Charles Garcia, Marina De Arruda Botelho, Delano Valdivino Santos Baptista, Cláudio Viegas, Saulo Santos Fortes","doi":"10.15392/2319-0612.2023.2295","DOIUrl":"https://doi.org/10.15392/2319-0612.2023.2295","url":null,"abstract":"The objective of the TBI treatment is the ablation of the bone marrow and the destruction of the circulating leukemia cells, once they are widely distributed throughout the body. Using beam parameters acquired under conventional SSD in TBI treatments may add non-negligible uncertainties in the monitor units calculation or in the beam profiles. The study, aims to commission the 6 and 10 MV photon beams, of the Varian accelerator CX model. A slab phantom and dosimetric assembly were used under TBI conditions. The accuracy of the TPS was evaluated against the experimental data. A set of data were acquired, highlighting the TPR table and methodology for calculating MU has been implemented. The TPS has presented a statistical uncertainty of ± 2.7 % compared to the experimental data for monitor unit calculation. The use of an acrylic spoiler has been shown to be clinically advantageous where, for a 6 MV beam, the entrance PDD was 75 % without a spoiler and 99.5 % with a spoiler. For a 10 MV beam, it was verified that without a spoiler, the entrance PDD was about 55 %, but with a spoiler, it was about 93 %. For medium Heterogeneous the TPS underestimated dose values by up to - 3.5 % with a mean deviation of – 2.9 %, for 6 MV and for 10 MV, the TPS overestimated the dose values by up to 1.1 %, with an average deviation of 1.0 % using the acrylic thorax phantom. The data obtained can be used clinically.","PeriodicalId":9203,"journal":{"name":"Brazilian Journal of Radiation Sciences","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135925282","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 : 2023-08-31DOI: 10.15392/2319-0612.2023.2291
Fernando Codelo Nascimento, P. M. Munhoz, Luiz Fernando Núbile Nascimento, W. Calvo
Paint is a prevalent type of surface of coating well known to most peoPaint is a prevalent type of surface of coating well known to most people. It is an easy-to-apply product, with excellent physical and chemical resistance and a wide range of applications. The function of a paint is to protect and beautify amongst other properties. Paints are formed using five components: resin, pigments, fillers, solvents and additives. This work deals with a specific type of paint, composed of a water-based acrylic emulsion, whose film formation is by coalescence and used to coat walls and other surfaces. The aim of this innovative research was to evaluate the effect of the addition of cellulosic dispersion of waste paper tissues treated by electron beam irradiation to an acrylic emulsion-based paint. The methodology used was a case study carried out at the Nuclear and Energy Research Institute that consisted of adding aqueous dispersions of cellulosic wipes with mass concentrations varying from 0.1% to 10% in deionized water, and treated by electron beam processing with absorbed doses from 5 kGy to 50 kGy. The results obtained followed the parameters of the Abrafati Sectorial Quality Program. The main sample parameters analyzed were specific density, which reached an average of 1.35 g/cm3; and covering power, whose value of 93.55% was above the specified limit (minimum of 90%). Among other results obtained, improvements in appearance, applicability and functionality were significant. It was concluded that this research constitutes an incremental improvement to the acrylic emulsion paints segment, and environmental sustainability, through the reuse of cellulosic tissue residues
{"title":"Development of an acrylic emulsion paint added with cellulosic dispersion treated with an electron beam accelerator","authors":"Fernando Codelo Nascimento, P. M. Munhoz, Luiz Fernando Núbile Nascimento, W. Calvo","doi":"10.15392/2319-0612.2023.2291","DOIUrl":"https://doi.org/10.15392/2319-0612.2023.2291","url":null,"abstract":"Paint is a prevalent type of surface of coating well known to most peoPaint is a prevalent type of surface of coating well known to most people. It is an easy-to-apply product, with excellent physical and chemical resistance and a wide range of applications. The function of a paint is to protect and beautify amongst other properties. Paints are formed using five components: resin, pigments, fillers, solvents and additives. This work deals with a specific type of paint, composed of a water-based acrylic emulsion, whose film formation is by coalescence and used to coat walls and other surfaces. The aim of this innovative research was to evaluate the effect of the addition of cellulosic dispersion of waste paper tissues treated by electron beam irradiation to an acrylic emulsion-based paint. The methodology used was a case study carried out at the Nuclear and Energy Research Institute that consisted of adding aqueous dispersions of cellulosic wipes with mass concentrations varying from 0.1% to 10% in deionized water, and treated by electron beam processing with absorbed doses from 5 kGy to 50 kGy. The results obtained followed the parameters of the Abrafati Sectorial Quality Program. The main sample parameters analyzed were specific density, which reached an average of 1.35 g/cm3; and covering power, whose value of 93.55% was above the specified limit (minimum of 90%). Among other results obtained, improvements in appearance, applicability and functionality were significant. It was concluded that this research constitutes an incremental improvement to the acrylic emulsion paints segment, and environmental sustainability, through the reuse of cellulosic tissue residues","PeriodicalId":9203,"journal":{"name":"Brazilian Journal of Radiation Sciences","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83616022","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 : 2023-08-24DOI: 10.15392/2319-0612.2023.2273
João Vitor do Carmo Barbosa, Guilherme Cavalcante de Albuquerque Souza, R. Gontijo, B. M. Mendes, A. V. Ferreira
In preclinical PET, SUV (standardized uptake value) is a robust quantifier that can be used to analyze PET images. Several factors – biological or technical – can affect SUV determination. Among technical factors, it is possible to cite the reconstruction protocols of PET images. This work evaluated the influence of two resolution modes – standard and high – on mean and maximum SUVs. The PET image of a mouse with a tumor in left flank was chosen from a PET image bank and reconstructed using two different protocols varying the resolution mode. The post-processing of images was performed using AMIDE software and eight volumes of interest (VOIs) were defined. Qualitatively, there was light improvement in structures definition in high-resolution image compared to standard resolution image. At the semiquantitative analysis, image reconstruction protocols using high-resolution mode did not significantly improve the recuperation of radiopharmaceutical uptake into analyzed tissues.
{"title":"Influence of the resolution mode on mean and maximum SUV for PET images acquired by a LabPET SOLO 4 scanner","authors":"João Vitor do Carmo Barbosa, Guilherme Cavalcante de Albuquerque Souza, R. Gontijo, B. M. Mendes, A. V. Ferreira","doi":"10.15392/2319-0612.2023.2273","DOIUrl":"https://doi.org/10.15392/2319-0612.2023.2273","url":null,"abstract":"In preclinical PET, SUV (standardized uptake value) is a robust quantifier that can be used to analyze PET images. Several factors – biological or technical – can affect SUV determination. Among technical factors, it is possible to cite the reconstruction protocols of PET images. This work evaluated the influence of two resolution modes – standard and high – on mean and maximum SUVs. The PET image of a mouse with a tumor in left flank was chosen from a PET image bank and reconstructed using two different protocols varying the resolution mode. The post-processing of images was performed using AMIDE software and eight volumes of interest (VOIs) were defined. Qualitatively, there was light improvement in structures definition in high-resolution image compared to standard resolution image. At the semiquantitative analysis, image reconstruction protocols using high-resolution mode did not significantly improve the recuperation of radiopharmaceutical uptake into analyzed tissues.","PeriodicalId":9203,"journal":{"name":"Brazilian Journal of Radiation Sciences","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83355679","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 : 2023-08-03DOI: 10.15392/2319-0612.2023.2274
S. Sawe
Assessment of public exposure to background radiation was performed in Manyoni, Tanzania to address public concerns following the discovery of uranium deposits in their neighborhoods. Results show that the highest concentrations of radionuclides are 112, 95 and 463 Bq.kg-1 for 226Ra, 232Th and 40K, respectively. The highest annual effective dose to the public is 2.91 mSv.y-1 with a mean value of 1.29 mSv.y-1. Authorities may use these results to address public concerns as well as the baseline information. Further investigations on public exposures in Manyoni are recommended.
{"title":"Public Exposure to Natural Radioactivity Near Uranium Deposits in Manyoni Area, Central Tanzania","authors":"S. Sawe","doi":"10.15392/2319-0612.2023.2274","DOIUrl":"https://doi.org/10.15392/2319-0612.2023.2274","url":null,"abstract":"Assessment of public exposure to background radiation was performed in Manyoni, Tanzania to address public concerns following the discovery of uranium deposits in their neighborhoods. Results show that the highest concentrations of radionuclides are 112, 95 and 463 Bq.kg-1 for 226Ra, 232Th and 40K, respectively. The highest annual effective dose to the public is 2.91 mSv.y-1 with a mean value of 1.29 mSv.y-1. Authorities may use these results to address public concerns as well as the baseline information. Further investigations on public exposures in Manyoni are recommended.","PeriodicalId":9203,"journal":{"name":"Brazilian Journal of Radiation Sciences","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75662089","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 : 2023-07-31DOI: 10.15392/2319-0612.2022.1993
Rubens Souza dos Santos
RMB is a multipurpose reactor to be built by CNEN. As a multipurpose facility, unlike a nuclear power plant, some operations may result in transients, whether during the movement of materials from remote irradiation, extraction of neutrons through beam holes, reactor starting up, control rod accident, etc. For that, a methodology to visualize some variables like neutron fluxes, temperatures, power, etc., was developed. In this one present some preliminary results based on multigroup diffusion theory, thermal hydraulics feedbacks, and numerical methods, systematized in the DINUCLE code. DINUCLE couples a numerical code of multigroup spatial kinetics, for calculations of the flux of neutrons in the core of reactors, with a numerical code for the analysis of thermo hydraulic transients in rods and plates, considering the refrigerant always single-phase. Use was made of a programming in VBA (Visual Basic for Applications) from Excel, for data visualization in the transient.
RMB是CNEN将建造的多用途反应堆。作为一个多用途设施，与核电站不同，某些操作可能会导致瞬变，无论是在材料从远程辐照中移动，通过束孔提取中子，反应堆启动，控制棒事故等过程中。为此，开发了一种可视化中子通量、温度、功率等变量的方法。本文提出了一些基于多群扩散理论、热工水力反馈和数值方法的初步结果，并在DINUCLE代码中进行了系统化。考虑到冷媒总是单相，DINUCLE将用于计算堆芯中子通量的多群空间动力学数值代码与用于分析棒和板的热水力瞬变的数值代码耦合在一起。利用Excel中的VBA (Visual Basic for Applications)编程，实现了瞬态数据的可视化。
{"title":"On the starting and operational transients at the core of the RMB based on 2D multigroup diffusion","authors":"Rubens Souza dos Santos","doi":"10.15392/2319-0612.2022.1993","DOIUrl":"https://doi.org/10.15392/2319-0612.2022.1993","url":null,"abstract":"RMB is a multipurpose reactor to be built by CNEN. As a multipurpose facility, unlike a nuclear power plant, some operations may result in transients, whether during the movement of materials from remote irradiation, extraction of neutrons through beam holes, reactor starting up, control rod accident, etc. For that, a methodology to visualize some variables like neutron fluxes, temperatures, power, etc., was developed. In this one present some preliminary results based on multigroup diffusion theory, thermal hydraulics feedbacks, and numerical methods, systematized in the DINUCLE code. DINUCLE couples a numerical code of multigroup spatial kinetics, for calculations of the flux of neutrons in the core of reactors, with a numerical code for the analysis of thermo hydraulic transients in rods and plates, considering the refrigerant always single-phase. Use was made of a programming in VBA (Visual Basic for Applications) from Excel, for data visualization in the transient.","PeriodicalId":9203,"journal":{"name":"Brazilian Journal of Radiation Sciences","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87382599","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 : 2023-07-28DOI: 10.15392/2319-0612.2023.2223
Rafaella M Ayllón, M. R. Furlan, T. M. El Hajj, P. S. C. Silva
The use of mining residues in agriculture may be possible, as long as there be previous studies in different areas, one of them being the analysis of the involved radionuclides behavior. This study determined the concentrations of 232Th activity in soil, soil treated with lime, soil with carbonate residue from niobium mining, soil with the mixture of lime and carbonate, in two moments. The transfer factor of 232Th from the soil to the plant was analyzed, in this case, lettuce (n=20), in the different types of treatment and in two moments. The addition of carbonate to the soils did not significantly alter the levels of radioactivity for 232Th radionuclide in lettuce. The effective dose resulting from the lettuce ingestion varied from 0.09 to 0.3 µSv y-1.
{"title":"Th-232 Radiological Aspects of Carbonate Niobium Mining Waste Use as Agricultural Amendment","authors":"Rafaella M Ayllón, M. R. Furlan, T. M. El Hajj, P. S. C. Silva","doi":"10.15392/2319-0612.2023.2223","DOIUrl":"https://doi.org/10.15392/2319-0612.2023.2223","url":null,"abstract":"The use of mining residues in agriculture may be possible, as long as there be previous studies in different areas, one of them being the analysis of the involved radionuclides behavior. This study determined the concentrations of 232Th activity in soil, soil treated with lime, soil with carbonate residue from niobium mining, soil with the mixture of lime and carbonate, in two moments. The transfer factor of 232Th from the soil to the plant was analyzed, in this case, lettuce (n=20), in the different types of treatment and in two moments. The addition of carbonate to the soils did not significantly alter the levels of radioactivity for 232Th radionuclide in lettuce. The effective dose resulting from the lettuce ingestion varied from 0.09 to 0.3 µSv y-1.","PeriodicalId":9203,"journal":{"name":"Brazilian Journal of Radiation Sciences","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84805063","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 : 2023-07-26DOI: 10.15392/2319-0612.2023.2118
Antônio Cezar Orozco, C. Federico, O. Gonçalez
Collimated thermal neutron beams are obtained from neutron extraction channels in nuclear reactors for various applications in research and technology, such as neutron imaging techniques (neutron radiography, neutron radioscopy, neutron tomography, and neutron-based autoradiography). Practical setups for neutron radiography using ion beams from particle accelerators and radioisotopic sources of fast neutrons have been also developed. However, only radioisotopic sources enable autonomous and transportable thermalization systems that can produce thermal neutron collimated beams. This work presents the performance results for a prototype of a compact system that generates a collimated beam of thermal neutrons using low-activity isotopic 241Am-Be sources. It was designed with the aid of Monte Carlo simulation using the PHITS v 3.17 program. Experimental measurements of the fluence of the neutron beam produced by the built prototype showed good agreement with the simulated values by the Monte Carlo method.
准直热中子束是从核反应堆的中子提取通道中获得的，用于各种研究和技术，如中子成像技术(中子放射照相、中子放射镜、中子层析成像和中子自放射照相)。利用粒子加速器和快中子放射性同位素源的离子束进行中子放射照相的实用装置也已开发出来。然而，只有放射性同位素源才能实现能够产生热中子准直光束的自主和可移动的热化系统。本工作介绍了一个紧凑系统的原型的性能结果，该系统使用低活度同位素241Am-Be源产生热中子准直束。采用PHITS v 3.17程序进行蒙特卡罗仿真设计。实验测量的中子束通量与蒙特卡罗方法的模拟值吻合较好。
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