Computer-aided sensitivity analysis of a multicriteria decision-making methodology for the evaluation of materials requirements stringency in the nuclear components manufacturing
Computer-aided sensitivity analysis of a multicriteria decision-making methodology for the evaluation of materials requirements stringency in the nuclear components manufacturing A methodology developed specifically for the evaluation of requirements of materials intended to high-demanding applications is the stringency levels methodology. The objective of this work is to perform a sensitivity analysis of the methodology of multicriteria stringency levels for the evaluation of technological requirements of materials, creating a new methodology that provides a final results studying variability that let us make an objective decision. The case study has been the evaluation of steels used in the manufacture of components housed in the primary loop of a nuclear power plant. To ease the calculation of the stringency levels, the algorithm has been computed in Labview®. Considering the dispersion that can generate the numerical weighting process, the analysis has shown that the variability in calculated values is not significant. The analysis proposed…
Analytical and numerical study for selecting polymeric matrix composites intended to demanding nuclear applications
Analytical and numerical study for selecting polymeric matrix composites intended to demanding nuclear applications This study describes a methodological proposal to select composite materials which are suitable to be employed to manufacture pipes that can properly withstand environments subjected to gamma and neutronic radiation. The methodology is used to select (see Figure 1) the optimal composite material whose properties are used afterwards to simulate several pipe sections by Finite Element Analysis, comparing the results with a well-known nuclear ferritic steel used in the manufacture of primary loop components. The most suitable composite material according to the defined criteria is composed of a phenolic resin matrix reinforced with long boron fibres and exhibit great properties to be used in a nuclear reactor environment: good radiation resistance and mechanical properties with a very low density and low cost. It can be concluded that, in some cases, composite material pipes could be an…
Requisitos previos a la fabricación de recipientes a presión en la industria nuclear
Requisitos previos a la fabricación de recipientes a presión en la industria nuclear La normativa de aplicación a la fabricación de vasijas y recipientes a presión establece una serie de requisitos a considerar antes del comienzo de la fabricación. Así, en este trabajo se exponen y analizan algunos requisitos preliminares establecidos en las normativas de diseño y fabricación americana y alemana, necesarios a considerar antes del inicio de la fabricación… See all…
Análisis técnico de factores críticos con influencia sobre la Corrosión Bajo Aislamiento y metodología de inspección basada en riesgo para su detección
Análisis técnico de factores críticos con influencia sobre la Corrosión Bajo Aislamiento y metodología de inspección basada en riesgo para su detección La corrosión bajo aislamiento es un fenómeno que normalmente afecta a tuberías y equipos a presión de acero al carbono, como resultado de la entrada o condensación de agua bajo el aislamiento térmico. Dentro de esta categoría de corrosión se puede incluir también la corrosión generada –por la misma causa– bajo el calorifugado de tubería y de equipos a presión. Este problema puede afectar a cualquier planta de proceso industrial, así como a centrales de generación de energía eléctrica basadas en un ciclo térmico como son las centrales nucleares con tecnología de reactor de agua ligera, que están en operación actualmente en nuestro país… See all…
Analytical and numerical study for selecting polymeric matrix composites intended to nuclear applications
Analytical and numerical study for selecting polymeric matrix composites intended to nuclear applications This study describes a methodological proposal to select composite materials which are suitable to be employed to manufacture pipes that can properly withstand environments subjected to gamma and neutronic radiation. The methodology is used to select, among many others, the optimal composite material whose properties are used afterwards to simulate several pipe sections by finite element analysis, comparing the results with a well-known nuclear-grade steel, WWER 15Kh2MFAA. The most suitable composite material according to the defined criteria is composed of a phenolic resin matrix reinforced with long boron fibres and exhibit great properties to be used in a nuclear reactor environment: good radiation resistance and mechanical properties with a very low density at low cost. It can be concluded that, in some cases, composite material pipes can be a better option than steel ones. Extending the method…
Evaluación cuantitativa del riesgo de fallos en servicio como herramienta para la gestión de la integridad de materiales en centrales nucleares
Evaluación cuantitativa del riesgo de fallos en servicio como herramienta para la gestión de la integridad de materiales en centrales nucleares En plantas de generación de energía mediante fisión nuclear -al igual que en otras plantas de proceso- es esencial identificar potenciales mecanismos de degradación de materiales, debidos a las severas condiciones de operación, con objeto de minimizar riesgos de fallo derivados. El objetivo del presente trabajo es realizar una revisión de las sistemáticas impulsadas por las agencias internacionales (como la IAEA e INPO) para la identificación y evaluación de riesgos en centrales nucleares, presentando una metodología nueva que permite evaluar cuantitativamente el riesgo de fallo de componentes con objeto de optimizar los planes de gestión del riesgo existentes. La metodología presentada -que incluye estrategias fundamentadas en las recomendaciones de las agencias internacionales- refrenda el hecho de que dichas acciones de gestión y mitigación del riesgo se encuentra en constante…
Análisis técnico-económico de la vida útil de materiales, equipos e infraestructuras para el transporte de hidrocarburos
Análisis técnico-económico de la vida útil de materiales, equipos e infraestructuras para el transporte de hidrocarburos La gestión de activos en el negocio del transporte de hidrocarburos es una tarea compleja que contempla numerosos aspectos. Para simplificar la evaluación de la vida útil de estos activos, en el presente trabajo se presenta una metodología para la evaluación de la vida útil de materiales, equipos e infraestructuras considerando aspectos técnico-económicos… View all…
Prediction of the Bilinear Stress-Strain Curve of Aluminum Alloys Using Artificial Intelligence and Big Data
Prediction of the Bilinear Stress-Strain Curve of Aluminum Alloys Using Artificial Intelligence and Big Data Aluminum alloys are among the most widely used materials in demanding industries such as aerospace, automotive or food packaging and, therefore, it is essential to predict the behavior and properties of each component. Tools based on artificial intelligence can be used to face this complex problem. In this work, a computer-aided tool is developed to predict relevant mechanical properties of aluminum alloys-Young’s modulus, yield stress, ultimate tensile strength and elongation at break. These predictions are based on the alloy chemical composition and tempers, and are employed to estimate the bilinear approximation of the stress-strain curve, very useful as a decision tool that helps in the selection of materials. The system is based on the use of artificial neural networks supported by a big data collection about technological characteristics of thousands of commercial materials. Thus, the…
Prediction of Physical and Mechanical Properties for Metallic Materials Selection Using Big Data and Artificial Neural Networks
Prediction of Physical and Mechanical Properties for Metallic Materials Selection Using Big Data and Artificial Neural Networks In this work, a computer-aided tool is developed to predict relevant physical and mechanical properties that are involved in the selection tasks of metallic materials. The system is based on the use of artificial neural networks supported by big data collection of information about the technological characteristics of thousands of materials. Thus, the volume of data exceeds 43k. The system can access an open online material library (a website where material data are recorded), download the required information, read it, filter it, organise it and move on to the step based on artificial intelligence. An artificial neural network (ANN) is built with thousands of perceptrons, whose topology and connections have been optimised to accelerate the training and predictive capacity of the ANN. After the corresponding training, the system is able to make predictions…
Fitness for Service and Reliability of Materials for Manufacturing Components Intended for Demanding Service Conditions in the Petrochemical Industry
Fitness for Service and Reliability of Materials for Manufacturing Components Intended for Demanding Service Conditions in the Petrochemical Industry A methodology has been developed to quantitatively assess the suitability of use and fitness for service of candidate materials using a novel approach that includes multiple perspectives. As a case study, a carbon steel pipe has been selected for operation in the petrochemical sector. The materials studied were the following: American Petroleum Institute (API) A25, A, B, X42, X46, X52, X56, X60, X65 and X70, as well as American Society for Testing and Materials (ASTM) A-106 Gr. A, B and C. The developed model combines an analytical multiperspective approach with calculation methods based on recognized prestige standards. In the present study, the following material degradation mechanisms have been considered: generalized corrosion, fracture due to mechanical overload and high-temperature degradation. Several novel analysis elements have been incorporated into this new methodology, such…