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Evaluation of elastic constants of materials using the frequency spectrum
Get PDFThe characterization of materials made with the support of non-destructive techniques has great importance in industrial applications. The ultrasonic techniques are distinguished by good resolution to measure small variations of wave velocities as a result of changes in the character suffered by a particular material. In general these ultrasonic techniques are studied in the time domain, which represents an experimental difficulties when thin materials are analyzed, as well as to attenuate the ultrasonic signal drastically. An ultrasonic technique that uses the frequency domain is used in this study aiming to provide good time measurements to calculate the elastic constants of the first order in an aluminum alloy 6351. With the aid of a statistical approach was possible to have good results of tests performed when compared by a time domain technique already well explored in Ultrasound works produced in the Nuclear Engineering Institute Laboratory (LABUS / IEN) and also presented in most of the package, in good agreement with the theoretical model established in literature and used to validate the experiment, which was found in the results with good approximation. The relevance of this work in the nuclear area is associated with the interest to know the mechanical properties of structural components of the nuclear industry, which is currently studied as a rule, resorting to the computer simulations or previously during the operation of the system
Integration of computerized operation support systems on a nuclear power plant environment
Get PDFAutomation of certain tasks in a Nuclear Power Plant (NPP) control room is expected to result in reduced operators’ mental workload, which may induce other benefits such as enhanced situation awareness and improved system performance. The final goal should be higher level of operational safety. Thus, recent works are increasingly assessing automation. The LABIHS compact NPP simulator, though, still operates under strictly manual printed hard-copy procedures, despite of the fact that the simulator incorporates several advancements in design of digitalized Human–System Interfaces (HSIs). This work presents the development, implementation and integration of selected components to achieve increased level of computerized/automated operation of the LABIHS compact NPP simulator. Specifically, we discuss three components: (i) Automatic Plant Mode Detection, (ii) Automatic Alarm Filtering, and (iii) Computerized Procedures. Each one of these components has to be carefully designed/integrated so that one can avoid the undesired effects of some known implementations of automated systems on NPP, such as the reduction in the operator's system awareness, an increase in monitoring workload, and the degradation in manual skills, which could lead to automation-induced system failures
A fuzzy framework for the usability evaluation of nuclear medical equipment.
No full textA fuzzy framework for the usability evaluation of nuclear medical equipmen
Preliminar analysis in support to the experimental activities on the mixing process in the pressurizer of a small modular reactor integrated primary system
Get PDFNowadays, there is a renewed interest in the development of advanced/innovative small and medium sized modular reactors (SMRs). The SMRs are variants of the Generation IV systems and usually have attractive characteristics of simplicity, enhanced safety and require limited financial resources. The concept of the integrated primary system reactor (IPSR) is characterized by the inclusion of the entire primary system within a single pressure vessel, including the steam generator and pressurizer. The pressurizer is located within the reactor vessel top, this configuration involves changes on the techniques and is necessary investigate the boron mixing. The present work represents a contribution to the design of an experimental facility planned to provide data relevant for the mixing phenomena in the pressurizer of a compact modular reactor. In particular, in order to evaluate the boron concentration in the surge orifices to simulate the in-surge and out-surge in a facility, scaled 1:200, respect to the ¼ of the pressurizer. The facility behavior studied from one inlet and one outlet of the test section with represent one in-surge e one out-surge the pressurizer of a small modular reactor integrated primary system
Diagnóstico de regimes bifásicos em um circuito de circulação natural através de uma técnica de visualização
Get PDFEste trabalho apresenta uma técnica de visualização para diagnóstico de regimes de escoamento bifásico água-vapor em um circuito de circulação natural. Os experimentos foram realizados no Circuito de Circulação Natural (CCN) do Laboratório de Termo-Hidráulica Experimental do Instituto de Engenharia Nuclear (LTE/IEN/CNEN), o qual consiste de um aquecedor, um trocador de calor, tubulações interligando estes componentes (perna quente, perna fria), e uma coluna de expansão. Na perna quente há uma seção transparente onde é possível observar o escoamento durante a operação do circuito em regime bifásico. Uma câmera de vídeo de alta velocidade foi posicionada em frente a seção transparente para filmagem, sendo os filmes gerados armazenados em um computador. Um aplicativo em MATLAB foi desenvolvido para o processamento das imagens. Esse aplicativo identifica a passagem de água e vapor por meio da diferença de pixels, gerando imagens em preto e branco correspondentes, respectivamente, a água e ao vapor. A partir do cálculo das áreas ocupadas pela água e bolhas de vapor nas imagens, obteve-se um indicador do regime de escoamento bifásico na forma de uma estimativa percentual da ocorrência de bolhas. Através desta metodologia três regimes foram diagnosticados: bubbly, “slug” e “churn”. Os resultados do software de diagnóstico concordam de modo satisfatório com a verificação visual dos vídeos filmados
Insights of probabilistic risk analysis on the development of severe accident management guidance: a case study for a plant similar to Angra I
Get PDFProbabilistic Risk Analysis (PRA) surges as a way to evaluate the risk of Nuclear Power Plants (NPPs) and to quantify it. Its objective was to track sequences of accidents and define mitigate actions to prevent core damage. But when the core is damaged the question is how to avoid releases of radionuclides to the environment. PRA evaluates this scenario too and is input to the Severe Accident Management Guidance (SAMG). This paper aims in the interaction between PRA and SAMG, both under development for the Brazilian NPPs, focusing in one specific Plant Damage State (PDS). The objective is to develop an Accident Progression Event Tree (APET) proposing the mitigate actions for the event, helping to understand the phenomena
Organizational model of the nuclear sector
Get PDFThe Brazilian Constitution prohibits private investment in many activities of the Nuclear Industry. Right now, it is in progress a constitutional amendment that allows private companies to build and operate nuclear power plants of its own. This work rescues the historical reasons that led the Congress of 1988 to choose the State owned model for this sector. In addition, the arguments that are used to propose the present changes are repeated here. As indicated in INAC 2015 website, "sustainable development is supported by three pillars: social, economic and environmental." Thus, the organizational model to be adopted for the Nuclear Sector must meet these requirements. The official objectives of the energy sector, as set out in the law 9,478, are remembered. New objectives, better established, and also adapted to the electrical subsector, are shown. Besides the use of these objectives to choose the sources and related technologies for the electric generation, they also can be used as evaluation criteria to help in the decision process of the organizational model for the Nuclear Sector. Acting in this way, it is ensured that social, economic and environmental requirements are being attended. Finally, if the developed evaluation criteria are applied, the impacts of each organizational model can be analyzed and preliminary conclusion and recommendation can be made
I0002 - Coleção de slides do Instituto de Engenharia Nuclear (IEN)
No full textColeção de slides, contendo 322 itens, pertencentes ao acervo de Documentos Históricos do instituto de Engenharia Nuclear
I0088 - Imagem da construção do Ciclotron
No full textDimensão: 8,8x12,6 cmFoto colorida do interior da caverna durante a construção do Ciclotron Compacto de Energia Variável, no Instituto de Engenharia Nuclear, na Ilha do Fundão, Rio de Janeiro
I0111 - Imagem do Ciclotron
No full textDimensão: 8,9x12,2 cmFoto P&B da vista geral da caverna do Ciclotron Compacto de Energia Variável, no Instituto de Engenharia Nuclear, na Ilha do Fundão, Rio de Janeiro