ALFREDO JOSE ALVIM DE CASTRO

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2017 - 20193
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Data final: 2019 × Data inicial: 2010 × Assunto: experimental data ×

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    Artigo IPEN-doc 26348
    Development of a new test section for the experimental analysis of critical velocity in flat plate fuel element for nuclear research reactor
    2019 - CASTRO, ALFREDO J.A. de; CEZARIO, PAULO F.S.
    The fuel elements of a MTR type nuclear reactor are mostly composed of aluminum containing the core of uranium sílica (U3Si2) dispersed in an aluminum matrix. These plates have a thickness of the order of millimeters and are much longer in relation to their thickness. This configuration, combined with the need for a flow at high flow rates to ensure the cooling of the fuel element in operation, may create problems of mechanical failure of fuel plate. In the case of critical velocity, excessive permanent deflections of the plates can cause blockage of the flow channel in the reactor core and lead to overheating in the plates. In the first work a test section that simulates a plate-like fuel element with three cooling channels was developed. The dimensions of the test section were based on the dimensions of the Fuel Element of the Brazilian Multipurpose Reactor (RMB). The critical velocity was reached with 14.5 m/s leading to the consequent plastic deformation of the flow channel plates. The signals of extensometers from the test section also showed excitation frequencies due to fluid related phenomena, for example: pressure pulse due to cavitations, fluid resonances, etc. The new test section is being designed to allow internal instrumentation and visualization for a better understanding of the fluid structure coupling. With this new section of test we intend to generate data that allow the assembly of a model that can better simulate the phenomenon of critical velocity for the RMB.
  • Imagem de Miniatura
    Artigo IPEN-doc 25523
    Experimental investigation of critical velocity in fuel element for the RMB reactor
    2018 - CASTRO, ALFREDO J.A. de; ANDRADE, DELVONEI A. de
    The fuel elements of a MTR (Material Testing Reactor) type nuclear reactor are mostly composed of aluminum-coated fuel plates containing the core of uranium silica (U3Si2) dispersed in an aluminum matrix. These plates have a thickness of the order of millimeters and are much longer in relation to their thickness. They are arranged in parallel inside the fuel element assembly to form channel gaps between them of only a few millimeters wide through which the coolant flows. This configuration, combined with the need for a flow at high flow rates to ensure the cooling of the fuel element in operation, may create problems of mechanical failure of fuel plate due to the vibration induced by the flow in the channels. In the case of critical velocity, excessive permanent deflections of the plates can cause blockage of the flow channel in the reactor core and, lead to overheating in the plates. For this work an experimental loop capable of high volume flows and a test section that simulates a plate-like fuel element with three cooling channels was developed. The dimensions of the test section were based on the dimensions of the Fuel Element of the Brazilian Multipurpose Reactor (RMB), whose project is being coordinated by the National Commission of Nuclear Energy (CNEN). The experiments performed had the objective of reaching Miller's critical velocity condition. The critical velocity was reached with 14.5 m/s leading to the consequent plastic deformation of the flow channel plates.
  • Imagem de Miniatura
    Artigo IPEN-doc 24029
    Experimental investigation of critical velocity in a parallel plate research reactor fuel assembly
    2017 - CASTRO, ALFREDO J.A.; SCURO, NIKOLAS L.; ANDRADE, DELVONEI A.
    The fuel elements of a MTR (Material Testing Reactor) type nuclear reactor are mostly composed of aluminumcoated fuel plates containing the core of uranium silica (U3Si2) dispersed in an aluminum matrix. These plates have a thickness of the order of millimeters and are much longer in relation to their thickness. They are arranged in parallel in the assembly of the fuel element to form channels between them a few millimeters in thickness, through which there is a flow of the coolant. This configuration, combined with the need for a flow at high flow rates to ensure the cooling of the fuel element in operation, may create problems of mechanical failure of fuel plate due to the vibration induced by the flow in the channels. In the case of critical velocity excessive permanent deflections of the plates can cause blockage of the flow channel in the reactor core and lead to overheating in the plates. For this study an experimental bench capable of high volume flows and a test section that simulates a plate-like fuel element with three cooling channels were developed. The dimensions of the test section were based on the dimensions of the Fuel Element of the Brazilian Multipurpose Reactor (RMB), whose project is being coordinated by the National Commission of Nuclear Energy (CNEN). The experiments performed attained the objective of reaching Miller's critical velocity condition. The critical velocity was reached with 14.5 m/s leading to the consequent plastic deformation of the flow channel plates.