Navegação Eventos - Artigos por autor "10050"

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  • IPEN-DOC 26190

    GERALDO, RICARDO R.; PASCHUK, SERGEI A.; BARRETO, RAFAEL C.; ZAHN, GUILHERME S. ; SILVA, PAULO S.C. da ; SILVA, AMANDA C.M.da; NARLOCH, DANIELLE C.; ARAUJO, ISABELLE C.. Application of semi-empirical model for the evaluation of radium activity in phosphogypsum used as component of clinker. In: INTERNATIONAL NUCLEAR ATLANTIC CONFERENCE, October 21-25, 2019, Santos, SP. Proceedings... Rio de Janeiro: Associação Brasileira de Energia Nuclear, 2019. p. 965-974.

    Abstract: Phosphogypsum is a residue that has been used by the cement industry as a substitute for the natural gypsum, used as a clinker additive during the production of Portland cement. There is a potential increase in this residue use since the large amount of phosphogypsum is generated as outcome of the phosphate fertilizer industries. However, phosphogypsum can be considered a source of radioactive contamination since it has 226Ra in its composition. Depending on the concentration of 226Ra, from the radiological protection point of view, this may cause a problem because this radionuclide and its direct decay product 222Rn along with other decay products, represent the largest fraction of radiation internal dose received by people. In order to evaluate the level of radiological risk that may be associated with the use of phosphogypsum, it is necessary to identify the concentration of 226Ra in building material. The aim of this research is to analyze the samples of phosphogypsum in relation to the concentrations of 226Ra, determined indirectly through 222Rn activity measurements. This measurement process has the advantage of being fast, convenient and relatively inexpensive when compared to traditional 226Ra concentration in samples measurement methods. Proposed physical-mathematical model was used to establish radium concentration from radon exhalation rate from cement mortar samples. The 222Rn activity measurements were performed with a portable detector with cubic phosphate samples with dimensions of 50x50x50mm3 allocated in a closed atmosphere of sampling chamber until secular equilibrium was reached. Obtained concentrations of radium activity in studied samples of phosphogypsum and cement mortars were found below the limits recommended by CNEN and international regulation.

    Palavras-Chave: concentration ratio; exhalation; gypsum cements; radiation detectors; radiation protection; radium 226; radon 222; brazilian cnen

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  • IPEN-DOC 26204

    COSTA, PRISCILA ; RAELE, MARCUS P. ; DOMIENIKAN, CLAUDIO ; MADI FILHO, TUFIC ; ZAHN, GUILHERME S. ; GENEZINI, FREDERICO A. . Characterization of a portable thermal neutron detector. In: INTERNATIONAL NUCLEAR ATLANTIC CONFERENCE, October 21-25, 2019, Santos, SP. Proceedings... Rio de Janeiro: Associação Brasileira de Energia Nuclear, 2019. p. 1163-1170.

    Abstract: A portable thermal neutron detector prototype, using a PIN-type silicon photodiode coupled to a boron converter, was developed at the Nuclear and Energy Research Institute (IPEN-CNEN/SP). Several boron layers were made by Pulsed Laser Deposition method and two different prototypes were made using distinct approaches in the associated electronics. The prototypes were characterized by measurements with the cold neutron beam at PHADES (Polarized 3He and Detector Experiment Station), in the NIST Center for Neutron Research. The distance between the prototype and the neutron source was different for each prototype: 70 cm (prototype one) and 7 cm (prototype two). The linearity behavior was verified for both prototypes in order to verify the relationship between counts and neutron fluence. The intrinsic efficiency values obtained for prototypes one and two were, respectively, (1.78 ± 0.01)% and (5.2 ± 0.4)%. The angular dependence was verified only for prototype one. The concept of this detector can be applied in a future dosimeter project.

    Palavras-Chave: thermal neutrons; photodiodes; portable equipment; silicon; cold neutrons; efficiency; neutron detectors; brazilian cnen

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  • IPEN-DOC 26151

    RIBEIRO JR., IBERÊ S. ; GENEZINI, FREDERICO A. ; ZAHN, GUILHERME S. . Comparison of two methodologies for spectra analysis in coincidence neutron activation analysis. In: INTERNATIONAL NUCLEAR ATLANTIC CONFERENCE, October 21-25, 2019, Santos, SP. Proceedings... Rio de Janeiro: Associação Brasileira de Energia Nuclear, 2019. p. 459-468.

    Abstract: The Research Reactor Center (CERPq) of IPEN-CNEN/SP has been developing a facility for Coincidence Neutron Activation Analysis (CNAA), a variation of the Neutron Activation Analysis technique in which gamma-gamma coincidence is used to reduce spectral interferences and improve detection limits of some elements. As the acquisition results in 2D-coincidence spectra, the spectrum analysis had to be dealt with accordingly. There are two distinct ways to perform these analyses, either directly, by fitting bidimensional peaks in the coincidence matrix, or by gating the spectra in one detector around each peak of interest and fitting the resulting 1D-spectrum in the usual way. In this work the concentrations of As, Co, Cs, Sb and Se were determined in geological and biological reference materials by CNAA using two different methodologies of analysis, using the BIDIM software, which provides 2D-peak-fitting; and a combination of the AnalisaCAEN suite, which gates the 2D-spectra, with Canberra’s Genie2000, which fits the resulting unidimensional spectra. The results allow for a discussion of the advantages and shortcomings of each method, both in terms of usability and of the reliability of the results.

    Palavras-Chave: biological materials; calibration standards; comparative evaluations; concentration ratio; geology; neutron activation analysis; spectra

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  • IPEN-DOC 26154

    JUNQUEIRA, LUCAS S. ; ANGELINI, MATHEUS ; ZAHN, GUILHERME S. ; SILVA, PAULO S.C. da . Determination of I-129 on radioactive waste from Angra 1 and 2 Power Plants. In: INTERNATIONAL NUCLEAR ATLANTIC CONFERENCE, October 21-25, 2019, Santos, SP. Proceedings... Rio de Janeiro: Associação Brasileira de Energia Nuclear, 2019. p. 492-495.

    Abstract: Radioactive waste must be characterized in order to be deposited in a suitable place for its confinement, avoiding any contamination of the environment. This study determined 129I, one of the difficult-to-measure nuclides that make up the radioactive waste from Angra 1 and 2 nuclear power plants. The methodology used a 129-I (1Bq/mL) liquid certified standard and consisted on guarantying that all the iodine was converted into iodide before the addition of PdCl2 for the precipitation of PdI2. After the separation procedure the 129I was quantified by gamma spectrometry by measuring its X-ray emissions with energies of 29.7 keV and 33.8 keV, as well as the gamma-ray emission of 39.6 keV. The chemical yield of the procedure was 74.4% (0,2).

    Palavras-Chave: activity meters; energy spectra; gamma spectroscopy; iodides; iodine 129; nuclear power plants; radioactive wastes; x-ray emission analysis

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  • IPEN-DOC 26198

    MELO, GLEISER R. de; ZAHN, GUILHERME S. ; MOREIRA, EDSON G. ; GENEZINI, FREDERICO A. . Development of an environmental monitoring station for HPGe detectors. In: INTERNATIONAL NUCLEAR ATLANTIC CONFERENCE, October 21-25, 2019, Santos, SP. Proceedings... Rio de Janeiro: Associação Brasileira de Energia Nuclear, 2019. p. 1097-1104.

    Abstract: Neutron Activation Analysis (NAA) is a well-established nondestructive analytic technique where the gamma radiation emitted by an irradiated sample is analyzed using an HPGe detector. The Neutron Activation Laboratory (LAN) of IPEN-CNEN/SP has been performing NAA analyses for over 30 years, and has plans of implementing quality control protocols to their analyses. In this sense, the environmental monitoring of the laboratories where the detectors are used has been performed for many years, in a manual way with no more than 2 measurements per day. In this work, an automated monitoring station based on a microcontroller Arduino UNO board has been developed which comprises four thermo hygrometer sensors for monitoring different parts of the environment, plus a thermocouple for monitoring the inside of the liquid nitrogen dewar. The results obtained allow for a discussion on the performance and adequacy of the sensors.

    Palavras-Chave: automation; cost; environment; high-purity ge detectors; monitoring; neutron activation analysis; performance; uses; brazilian cnen

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  • IPEN-DOC 26214

    AYLLON, RAFAELLA M. ; TORRECILHA, JEFFERSON K. ; SAUEIA, CATIA H.R. ; NISTI, MARCELO B. ; TORQUATO, HENRIQUE; EL HAJJ, THAMMIRIS M.; ZAHN, GUILHERME S. ; SILVA, PAULO S.C. da . External gamma exposure due to the application of carbonate niobium tailing as soil amendment. In: INTERNATIONAL NUCLEAR ATLANTIC CONFERENCE, October 21-25, 2019, Santos, SP. Proceedings... Rio de Janeiro: Associação Brasileira de Energia Nuclear, 2019. p. 1318-1327.

    Abstract: The storage of tailing from anthropic activities like mining, which may contain radionuclides, is a problematic situation consequent from NORM industries and for which alternatives should be sought. This paper presents the preliminary results for the use of a carbonate tailing derived from niobium extraction as soil amendment from the point of view of the radiological indices, since this material is a NORM residue. The activity concentration of radionuclides 226Ra, 228Ra and 40K were determined in six samples of carbonate by gamma spectrometry and the radiological hazard indices were calculated for the carbonate itself and simulated for soil application. The results indicated that the dilution of the carbonate in the soil do not increase the radiological hazard indices.

    Palavras-Chave: agriculture; carbonates; gamma spectroscopy; mining; naturally occurring radioactive materials; niobium; potassium 40; radiation hazards; radioactive wastes; radium 226; radium 228

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  • IPEN-DOC 26153

    JUNQUEIRA, LUCAS S. ; ZAHN, GUILHERME S. ; SILVA, PAULO S.C. da . Ni-59 determination by measurement of annihilation energy. In: INTERNATIONAL NUCLEAR ATLANTIC CONFERENCE, October 21-25, 2019, Santos, SP. Proceedings... Rio de Janeiro: Associação Brasileira de Energia Nuclear, 2019. p. 486-491.

    Abstract: Radioactive waste is subject to regulations regarding its inventory, transportation and final deposition. Such standards require the knowledge of the tailing contents in a way that is possible to accommodate them in a repository capable of containing their radiation completely. In this study a methodology was established for determining the concentration of 59Ni using the annihilation energy (0.511 MeV) between a positron from its + emission, and an electron that is widely present in matter. To ensure the reliability of the methodology, the area of the annihilation peak was compared to 59Ni Kα and Kβ x-ray peaks. To make this method viable the separations of Ni from the other components of the sample was necessary. This was done by using dimethylglyoxime (DMG) for Ni precipitation. Of all the Ni radioisotopes only 59Ni have a half-life longer than a few days, so that 59Ni can be determined without radioisotopical interferences. After precipitation with DMG, the substrate was vacuum filtered on filter paper, using an apparatus to preserve the geometry of the precipitate in different samples. The 59Ni precipitate was then counted in an extended range gamma spectrometer and the 511 keV peak compared to the Ni x-rays in order to verify the reliability of the method.

    Palavras-Chave: annihilation; comparative evaluations; dimethylglyoxime; gamma spectrometers; nickel 59; radioactive wastes; reliability; sampling

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  • IPEN-DOC 26230

    GENEZINI, FREDERICO A. ; ZAHN, GUILHERME S. ; SILVA, PAULO S.C. da ; NORY, RENATA M. ; MOREIRA, EDSON G. ; SANTIAGO, PAULO S. . On the feasibility of producing Lu-177 in the IEA-R1 reactor via the direct route. In: INTERNATIONAL NUCLEAR ATLANTIC CONFERENCE, October 21-25, 2019, Santos, SP. Proceedings... Rio de Janeiro: Associação Brasileira de Energia Nuclear, 2019. p. 1759-1765.

    Abstract: Over the last years the 177Lu radioisotope has attracted great interest for the use in therapeutic and diagnostic procedures simultaneously, being what is now called a theranostic radioisotope. There are mainly two ways of producing this radioisotope, by direct neutron capture in a 176Lu target (the \direct route") or by irradiating a 176Yb sample, producing 177Yb that will then decay to 177Lu (also referred as the \indirect route"). In this work the feasibility of producing 177Lu in the IEA-R1 nuclear reactor via the direct route was assessed, and the speci c activity that could be obtained was estimated both experimentally and theoretically, allowing for a discussion on the feasibility of commercially producing 177Lu by 176Lu neutron capture in the IEA-R1 reactor.

    Palavras-Chave: capture; feasibility studies; iear-1 reactor; isotope production; lutetium 176 target; lutetium 177; neutron reactions; nuclear medicine; therapy

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  • IPEN-DOC 26162

    TICIANELLI, REGINA B. ; ZAHN, GUILHERME S. ; SILVA, PAULO S.C. da ; GENEZINI, FREDERICO A. . Radionuclide analysis of the IEA-R1 pool water. In: INTERNATIONAL NUCLEAR ATLANTIC CONFERENCE, October 21-25, 2019, Santos, SP. Proceedings... Rio de Janeiro: Associação Brasileira de Energia Nuclear, 2019. p. 579-583.

    Abstract: IEA-R1 is a 5MW pool-type research reactor built in the late 1950's. In the last years, it operates at 4.5MW for 8h on Mondays, Tuesdays and Wednesdays. In every day of operation, a sample is taken from the pool water both before starting the reactor and at the end of the day and analyzed in an HPGe detector, in order to verify for possible problems with the fuel elements or other issues. In this work, the results obtained in these analyses spanning for some months are discussed regarding the radionuclides frequently identi ed and the dependence of their activities with time.

    Palavras-Chave: fuel elements; high-purity ge detectors; iear-1 reactor; radiochemical analysis; radioisotopes; radiometric analysis; time dependence; water

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Os filtros disponíveis em Navegar tais como: Coleções, Ano de publicação, Títulos, Assuntos, Autores, Revista, Tipo de publicação são autoexplicativos. O filtro, Autores IPEN apresenta uma relação com os autores vinculados ao IPEN; o ID Autor IPEN diz respeito ao número único de identificação de cada autor constante no RD e sob o qual estão agrupados todos os seus trabalhos independente das variáveis do seu nome; Tipo de acesso diz respeito à acessibilidade do documento, isto é , sujeito as leis de direitos autorais, ID RT apresenta a relação dos relatórios técnicos, restritos para consulta das comunidades indicadas.

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Buscar os artigos apresentados em um evento internacional de 2015, sobre loss of coolant, do autor Maprelian.

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Ano de publicação: 2015

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ATENÇÃO!

ESTE TEXTO "AJUDA" ESTÁ SUJEITO A ATUALIZAÇÕES CONSTANTES, A MEDIDA QUE NOVAS FUNCIONALIDADES E RECURSOS DE BUSCA FOREM SENDO DESENVOLVIDOS PELAS EQUIPES DA BIBLIOTECA E DA INFORMÁTICA.

O gerenciamento do Repositório está a cargo da Biblioteca do IPEN. Constam neste RI, até o presente momento 20.950 itens que tanto podem ser artigos de periódicos ou de eventos nacionais e internacionais, dissertações e teses, livros, capítulo de livros e relatórios técnicos. Para participar do RI-IPEN é necessário que pelo menos um dos autores tenha vínculo acadêmico ou funcional com o Instituto. Nesta primeira etapa de funcionamento do RI, a coleta das publicações é realizada periodicamente pela equipe da Biblioteca do IPEN, extraindo os dados das bases internacionais tais como a Web of Science, Scopus, INIS, SciElo além de verificar o Currículo Lattes. O RI-IPEN apresenta também um aspecto inovador no seu funcionamento. Por meio de metadados específicos ele está vinculado ao sistema de gerenciamento das atividades do Plano Diretor anual do IPEN (SIGEPI). Com o objetivo de fornecer dados numéricos para a elaboração dos indicadores da Produção Cientifica Institucional, disponibiliza uma tabela estatística registrando em tempo real a inserção de novos itens. Foi criado um metadado que contém um número único para cada integrante da comunidade científica do IPEN. Esse metadado se transformou em um filtro que ao ser acionado apresenta todos os trabalhos de um determinado autor independente das variáveis na forma de citação do seu nome.

A elaboração do projeto do RI do IPEN foi iniciado em novembro de 2013, colocado em operação interna em julho de 2014 e disponibilizado na Internet em junho de 2015. Utiliza o software livre Dspace, desenvolvido pelo Massachusetts Institute of Technology (MIT). Para descrição dos metadados adota o padrão Dublin Core. É compatível com o Protocolo de Arquivos Abertos (OAI) permitindo interoperabilidade com repositórios de âmbito nacional e internacional.

1. Portaria IPEN-CNEN/SP nº 387, que estabeleceu os princípios que nortearam a criação do RDI, clique aqui.


2. A experiência do Instituto de Pesquisas Energéticas e Nucleares (IPEN-CNEN/SP) na criação de um Repositório Digital Institucional – RDI, clique aqui.