999 resultados para Acidente nuclear, Brasil


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This research had the objective to verify if the current organization design of the Comissão Nacional de Energia Nuclear (CNEN) facilitates or makes it difficult the reach of the organization performance. In order to make the analysis, the used ways had been bibliographic, documental and field researches. The bibliographical survey allowed to conclude that it has a necessity of searching a balance between the objectivist and subjectivist approaches of the theory of the organization design. The documental survey supplied elements that they make possible to understand the main phases of the development of the CNEN in elapsing of the time and that they explain the current organization design. Finally, the research of field, carried through with the main managers of the institution, made possible the data-collecting that contributed to ratify the initial assumption of the research of that the current organization design of the CNEN makes it difficult the performance of the organization.

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Os primeiros anos da política nuclear brasileira, entre os anos de 1945 e 1956, é o assunto tratado no presente trabalho. Aqui procuramos compreender as razões por trás da vitória de Álvaro Alberto na CPI da Questão Nuclear de 1956, na qual as suas propostas para o setor foram valorizadas e restabelecidas, mesmo após o Almirante ter sofrido derrotas durante o governo Café Filho (1954-55), quando foi exonerado da presidência do CNPq e teve a sua política atômica suspensa. O trabalho conclui que a vitória foi possível graças ao fato de as suas diretrizes para a área nuclear terem ressonância junto a diversos setores da sociedade brasileira adeptos do monopólio estatal sobre os recursos naturais e de um desenvolvimento científico e tecnológico em bases autônomas; além de uma conjuntura política excepcional no início do governo de Juscelino Kubitschek, marcado por forte polarização política, na qual o assunto nuclear ganhou projeção nacional. Com a sua vitória na CPI de 1956, Álvaro Alberto logrou definir os termos debate sobre a política a ser adotada na área atômica pelos anos e décadas seguintes.

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O recorte analítico deste trabalho percorre os anos entre 1975 e 1990, fazendo uma análise sobre diferentes instâncias de oposição doméstica ao Programa Nuclear Brasileiro. A aludida oposição é entendida dentro do contexto político que o Brasil atravessava neste período, que coincide com a distensão do regime militar, a transição para governos civis e, depois, democraticamente eleitos. Nesse sentido, para além de construir uma narrativa sobre oposições domésticas ao programa nuclear e contribuir para as recentes interpretações historiográficas sobre a energia nuclear no Brasil, este trabalho busca situar estes atores dentro do contexto histórico do Brasil, avaliando seu impacto tanto na política nuclear quanto no contexto mais amplo da longa transição que encerrou o regime militar e trouxe o poder de volta para os civis.

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Centro de Pesquisa e Documentação de História Contemporânea do Brasil

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Since its discovery, radioactivity has brought numerous benefits to human societies. It has many applications in medicine, serving as a tool for non-invasive methods for diagnosis and therapies against diseases such as cancer. It also applies to technologies for energy in nuclear power plants with relatively low impacts on terms of perfect security. All applications, however, have risks, requiring maximum caution to drive processes and operations involving radioactive elements because, once released into the environment, they have extremely harmful effects on organisms affected. This paper presents fundamental concepts and principles of nuclear physics in order to understand the effects of radioactive elements released into the environment, culminating on the issue of radioactive contamination. Literature review allowed us to understand the radioactive contamination problem on living beings. Three major nuclear accidents have happened in the last thirty years, two of them in consecutive years. The nuclear accident at Chernobyl, Ukraine, in 1986, polluted large areas, condemning hundreds of thousands of people to live with consequences of the accident and effects of radiation, killing thousands of people throughout the years. In 1987, a major radiological accident occurred in Goiania (GO) when a source of radioactive cesium was violated, leading to the death of those who had direct or indirect contact with cesium. The most recent accident, in March, 2011, was located at the nuclear power plant in Fukushima Prefecture, Japan, after an earthquake and tsunami hit the region. There is no extensive and accurate knowledge about the consequences of the contamination entailed in that accident, although it is possible to verify signals on a global scale. An analysis of reports of contamination of large areas generated by nuclear plants with release of hazardous wastes suggests it is necessary to rethink the energy matrix of the various countries...

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Pós-graduação em Relações Internacionais (UNESP - UNICAMP - PUC-SP) - FFC

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Energy is a vital resource for social and economic development. In the present scenario, the search for alternative energy sources has become fundamental, especially after the oil crises between 1973 and 1979, the Chernobyl nuclear accident in 1986 and the Kyoto Protocol in 1997. The demand for the development of new alternative energy sources aims to complement existing forms allows to meet the demand for energy consumption with greater security. Brazil, with the guideline of not dirtying the energy matrix by the fossil fuels exploitation and the recent energy crisis caused by the lack of rains, directs energy policies for the development of other renewable energy sources, complementing the hydric. This country is one of the countries that stand out for power generation capacity from the winds in several areas, especially Rio Grande do Norte (RN), which is one of the states with highest installed power and great potential to be explored. In this context arises the purpose of this work to identify the incentive to develop policies of wind energy in Rio Grande do Norte. The study was conducted by a qualitative methodology of data analysis called content analysis, oriented for towards message characteristics, its informational value, the words, arguments and ideas expressed in it, constituting a thematic analysis. To collect the data interviews were conducted with managers of major organizations related to wind energy in Brazil and in the state of Rio Grande do Norte. The identification of incentive policies was achieved in three stages: the first seeking incentives policies in national terms, which are applied to all states, the second with the questionnaire application and the third to research and data collection for the development of the installed power of the RN as compared to other states. At the end, the results demonstrated hat in Rio Grande do Norte state there is no incentive policy for the development of wind power set and consolidated, specific actions in order to optimize the bureaucratic issues related to wind farms, especially on environmental issues. The absence of this policy hinders the development of wind energy RN, considering result in reduced competitiveness and performance in recent energy auctions. Among the perceived obstacles include the lack of hand labor sufficient to achieve the reporting and analysis of environmental licenses, the lack of updating the wind Atlas of the state, a shortfall of tax incentives. Added to these difficulties excel barriers in infrastructure and logistics, with the lack of a suitable port for large loads and the need for reform, maintenance and duplication of roads and highways that are still loss-making. It is suggested as future work the relationship of the technology park of energy and the development of wind power in the state, the influence of the technology park to attract businesses and industries in the wind sector to settle in RN and a comparison of incentive policies to development of wind energy in the Brazilian states observing wind development in the same states under study.

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Ceramic materials have been widely used for various purposes in many different industries due to certain characteristics, such as high melting point and high resistance to corrosion. Concerning the areas of applications, automobile, aeronautics, naval and even nuclear, the characteristics of these materials should be strictly controlled. In the nuclear area, ceramics are of great importance once they are the nuclear fuel pellets and must have, among other features, a well controlled porosity due to mechanical strength and thermal conductivity required by the application. Generally, the techniques used to characterize nuclear fuel are destructive and require costly equipment and facilities. This paper aims to present a nondestructive technique for ceramic characterization using ultrasound. This technique differs from other ultrasonic techniques because it uses ultrasonic pulse in frequency domain instead of time domain, associating the characteristics of the analyzed material with its frequency spectrum. In the present work, 40 Alumina (Al2O3) ceramic pellets with porosities ranging from 5% to 37%, in absolute terms measured by Archimedes technique, were tested. It can be observed that the frequency spectrum of each pellet varies according to its respective porosity and microstructure, allowing a fast and non-destructive association of the same characteristics with the same spectra pellets.

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In Nuclear Medicine, radioiodine, in various chemical forms, is a key tracer used in diagnostic practices and/or therapy. Due to its high volatility, medical professionals may incorporate radioactive iodine during the preparation of the dose to be administered to the patient. In radioactive iodine therapy doses ranging from 3.7 to 7.4GBq per patient are employed. Thus, aiming at reducing the risk of occupational contamination, we developed a low cost filter to be installed at the exit of the exhaust system where doses of radioactive iodine are fractionated, using domestic technology. The effectiveness of radioactive iodine retention by silver impregnated silica [10%] crystals and natural activated carbon was verified using radiotracer techniques. The results showed that natural activated carbon is effective for I2 capture for a large or small amount of substrate but its use is restricted due to its low flash point (150º C). Besides, when poisoned by organic solvents, this flash point may become lower, causing explosions if absorbing large amounts of nitrates. To hold the CH3I gas, it was necessary to increase the volume of natural activated carbon since it was not absorbed by SiO2 + Ag crystals. We concluded that, for an exhaust flow range of (306 4) m3/h, a double stage filter using SiO2 + Ag in the first stage and natural activated carbon in the second is sufficient to meet radiological safety requirements.