Materials Selection Criteria for Nuclear Power Applications: A Decision Algorithm
Materials Selection Criteria for Nuclear Power Applications: A Decision Algorithm An innovative methodology based on stringency levels is proposed in this paper and improves the current selection method for structural materials used in demanding industrial applications. This paper describes a new approach for quantifying the stringency of materials requirements based on a novel deterministic algorithm to prevent potential failures. We have applied the new methodology to different standardized specifications used in pressure vessels design, such as SA-533 Grade B Cl.1, SA-508 Cl.3 (issued by the American Society of Mechanical Engineers), DIN 20MnMoNi55 (issued by the German Institute of Standardization) and 16MND5 (issued by the French Nuclear Commission) specifications and determine the influence of design code selection. This study is based on key scientific publications on the influence of chemical composition on the mechanical behavior of materials, which were not considered when the technological requirements were established in the aforementioned specifications.…
Quantitative model for predicting the suitability of candidate materials for reactor pressure-vessels manufacturing
Quantitative model for predicting the suitability of candidate materials for reactor pressure-vessels manufacturing In this work, an integrative approach that eases the material selection stage is presented. Twenty different specifications of materials from 1st to 4th generation of pressurized water reactors have been analyzed, covering the main designs of pressurized reactors from Western Europe, Japan and Russia. Thus, the results show that steels 15Kh2MFAA, 20MnMoNi55 and SA533 Gr.B Cl.1 are the best material options to prevent the embrittlement induced by radiation… See all…
Análisis de requisitos tecnológicos de materiales especificados en normativas reguladas y su repercusión sobre la fabricación de recipientes especiales para la industria nuclear
Análisis de requisitos tecnológicos de materiales especificados en normativas reguladas y su repercusión sobre la fabricación de recipientes especiales para la industria nuclear Resumen Durante la concepción de cualquier proyecto industrial que contenga la construcción o fabricación de algún elemento con función estructural, es de suma importancia tras la selección de los materiales a emplear, realizar una adecuada selección de la normativa que describe los requisitos tecnológicos, con el objeto de asegurar que los materiales sean adecuados para la finalidad inicialmente prevista. En la práctica, en base a las principales propiedades químicas y mecánicas del material, se establecen equivalencias entre las distintas especificaciones normalizadas de materiales. No obstante, los requisitos tecnológicos especificados por las distintas normativas para los materiales considerados como equivalentes, presentan en muchos casos diferencias significativas. En base a esto, en la presente Tesis Doctoral se analizan requisitos tecnológicos de materiales empleados en la fabricación de recipientes especiales…
Fragilización por irradiación neutrónica de la vasija: algunas consideraciones para la selección de materiales
Fragilización por irradiación neutrónica de la vasija: algunas consideraciones para la selección de materiales Los materiales expuestos a radiación neutrónica generada por reacciones de fisión nuclear sufren un daño considerable a dosis muy bajas de irradiación, sufriendo una reducción de su ductilidad. Así, la fragilización por irradiación de aceros es el principal mecanismo de envejecimiento que afecta a las vasijas a presión de los reactores nucleares de agua ligera. En este sentido, existen numerosas bases de datos que muestran resultados obtenidos en los programas de vigilancia de las propiedades mecánicas de aceros de vasija. Así, el objeto del presente trabajo es realizar un análisis técnico de requisitos de composición química de materiales de vasija empleando un modelo de decisión basado en niveles de severidad. En este estudio se han tenido en cuenta ciertos resultados obtenidos durante la realización de programas de vigilancia de propiedades mecánicas. Así, el estudio realizado aúna…
Prediction of the Mechanical Behaviour of Cladding Materials for Nuclear Reactor Pressure–Vessels Based on the Analysis of Technological Requirements
Prediction of the Mechanical Behaviour of Cladding Materials for Nuclear Reactor Pressure–Vessels Based on the Analysis of Technological Requirements A prediction of the mechanical behaviour based on the analysis of standardized requirements is essential to optimize the technical characteristics of materials used in cladding automatic-processes for nuclear reactor pressure-vessels, being crucial to prevent failures. The aim of this work is to develop a quantitative analysis of requirements of the AISI 304 and AISI 347 materials, and their German equivalents, DIN X5CrNi18-10 and DIN X6CrNiNb18-10, respectively, in order to predict the mechanical behavior. To this purpose, we have carried out prediction studies based on the estimation of ferrite-δ content and its relationship with hot-cracking described in the literature. Additionally, chemical and mechanical requirements have been evaluated by the application of a deterministic algorithm based on Stringency Levels. Results show that steel DIN X6CrNiNb18-10 can be defined as the best option, because…
Novel computer-aided methodology for selecting materials for the nuclear industry
Novel computer-aided methodology for selecting materials for the nuclear industry Since, in the design phase of the project, the materials selection is a difficult task it is necessary to have a methodology to help in the selection process of materials. The objective of this research work is the development of a computer-aided methodology for selecting materials standards. The comparison between two specifications of nuclear materials such as the SA-508 Cl.3 specification (described in ASME B&PV Code) and the DIN 20MnMoNi55 one (described in the KTA standards) was chosen as a case study. The methodology developed is based on a evaluation method of stringency of requirements using a numerical weighting process based on the opinion of a prestigious experts panel in selection of materials for the nuclear industry. The developed program has the advantage that after making any changes in the input parameters, the final value is recalculated instantly, being very…
Nueva metodología asistida por ordenador para la selección de materiales destinados a la industria nuclear
Nueva metodología asistida por ordenador para la selección de materiales destinados a la industria nuclear Dado que en la fase de diseño de proyecto, la selección de materiales puede ser una ardua tarea, resulta necesario disponer de una metodología de ayuda en dicho proceso de selección. El objetivo de este trabajo de investigación es el desarrollo de una herramienta informatizada para la selección de normativa de materiales. Se ha escogido como caso de estudio la comparación de dos especificaciones de materiales como son, la especificación SA-508 Cl.3 descrita en el código ASME B&PV y la DIN 20MnMoNi55 descrita en las normas KTA. La herramienta desarrollada se basa en una metodología de niveles de severidad de requisitos, empleando un proceso de ponderación numérica basado en la consulta a un prestigioso panel de expertos en selección de materiales para la industria nuclear. El programa desarrollado presenta como ventaja que, tras realizar cualquier…
Consideraciones técnicas acerca de los programas regulados para la vigilancia de las propiedades de aceros de vasija en reactores nucleares
Consideraciones técnicas acerca de los programas regulados para la vigilancia de las propiedades de aceros de vasija en reactores nucleares Revista Industria Química. La vasija del reactor es uno de los componentes más críticos para la extensión del periodo de operación de centrales nucleares. Para evitar accidentes es necesario realizar una adecuada selección de requisitos tecnológicos de diseño y fabricación de la vasija, así como un correcto seguimiento del comportamiento de los materiales. Palabras clave: Energía nuclear, Regulación vida útil, Envejecimiento aceros, Programas de vigilancia The reactor vessel is one of the most critical for extending the period of operation of nuclear power plants components. To avoid accidents is necessary to make a proper selection of technological requirements, design and manufacture of the vessel, as well as proper monitoring of the behavior of materials… See all…
Proposal to quantify the efficacy of technological requirements of structural materials for the nuclear sector
Proposal to quantify the efficacy of technological requirements of structural materials for the nuclear sector Equivalences between different standardized specifications of materials are usually established with respect to their main chemical and mechanical properties. However, the technological requirements described by equivalent specifications sometimes exhibit significant differences between them. Additionally, publications of key importance about the influence of the chemical composition on the mechanical behaviour of material have not often been taken into account. The aim of this work is to develop a decision tool to distinguish between two different specifications based in the quantification of the efficacy of technological requirements. We have developed a deterministic algorithm that provides a quantifiable value of the efficacy of each requirement, which has been defined as Stringency Level. This methodology has been applied to SA 508 Class 3 nuclear specification included in ASME B&PV American Code and DIN 20MnMoNi55 as described by KTA German…
Novel Approach in Materials Selection for Reactor Pressure-Vessels Manufacturing
Novel Approach in Materials Selection for Reactor Pressure-Vessels Manufacturing A novel prediction method of irradiation embrittlement in reactor pressure vessels (RPV) steels is proposed in this work in order to improve the current materials selection methods for nuclear power applications. This work describes a new approach, based on a decision algorithm called stringency level method (SLM), for quantifying the stringency of chemical and mechanical requirements of the most relevant structural materials used in the manufacturing of all generations of RPVs. More than 200 different technological requirements from 20 different material specifications are analyzed. Additionally, we compare the outputs obtained from SLM with the embrittlement prediction model proposed by American regulatory guide 1.99 (R.G. 1.99 Rev.2). From this integrated approach, the final results show that steel DIN 20MnMoNi55 is the best material option, followed by WWER 15Kh2MFAA and SA-533 Gr.B Cl.1. Thus, more recently developed materials exhibit requirements more stringent than…