Fundamentals of 3-D Neutron Kinetics and Current Status

This lecture includes the following topics: 1) A summary of the cell and lattice calculations used to generate the neutron reaction data for neutron kinetics, including the spectral and burn up calculations of LWR cells and fuel assembly lattices, and the main nodal kinetics parameters: mean neutron generation time and delayed neutron fraction; 2) the features of the advanced nodal methods for 3-D LWR core physics, including the treatment of partially inserted control rods, fuel assembly grids, fuel burn up and xenon and samarium transients, and ex core detector responses, that are essential for core surveillance, axial offset control and operating transient analysis; 3) the advanced nodal methods for 3-D LWR core neutron kinetics (best estimate safety analysis, real time simulation); and 4) example applications to 3-D neutron kinetics problems in transient analysis of PWR cores, including model, benchmark and operational transients without, or with simple, thermal-hydraulics feedback

Basis for Coupled 3-D Neutronics-Thermal-Hydraulics

The purpose of this seminar is first to discuss the basis of the coupling between 3-D Neutron- Kinetics and Thermal-Hydraulics codes, including the control and 3-D variables to interchange, the transform of the 3-D NK and TH core nodalizations, and the schemes for temporal coupling and time-step control. As representative examples of the NK-TH core coupling, we discuss first the integration of a 3-D NK nodal code with a TH subchannel code, for detailed transient core analysis; and second the coupling of 3-D NK nodal codes with TH system codes, for general transient and safety analysis. In chapter 2, we analyze several prototype model transients in PWR, where large 3-D core asymmetries are found and the NK-TH coupling is quite significant, including loss-of-flow and symmetric and asymmetric core cooling, considering the effects on the responses of the excore detectors. In chapter 3, we discuss the analysis of an increase-of-flow transient actually occurred in an operating PWR and the comparison with the measured data. In chapter 4, we summarize the phenomena and results of the calculations of the NEA/NSC Benchmark on the main steam line break (MSLB) transient in a PWR. Finally, we will discuss the state-of-the-art issues in LWR coupled NK-TH 3-D transient analysis and ongoing and planned computational developments

Development of an Analytic Nodal Diffusion Solver in Multigroups for 3D Reactor Cores with Rectangular or Hexagonal Assemblies.

More accurate modelling of physical phenomena involved in present and future nuclear reactors requires a multi-scale and multi-physics approach. This challenge can be accomplished by the coupling of best-estimate core-physics, thermal-hydraulics and multi-physics solvers. In order to make viable that coupling, the current trends in reactor simulations are along the development of a new generation of tools based on user-friendly, modular, easily linkable, faster and more accurate codes to be integrated in common platforms. These premises are in the origin of the NURESIM Integrated Project within the 6th European Framework Program, which is envisaged to provide the initial step towards a Common European Standard Software Platform for nuclear reactors simulations. In the frame of this project and to reach the above-mentioned goals, a 3-D multigroup nodal solver for neutron diffusion calculations called ANDES (Analytic Nodal Diffusion Equation Solver) has been developed and tested in-depth in this Thesis. ANDES solves the steady-state and time-dependent neutron diffusion equation in threedimensions and any number of energy groups, utilizing the Analytic Coarse-Mesh Finite-Difference (ACMFD) scheme to yield the nodal coupling equations. It can be applied to both Cartesian and triangular-Z geometries, so that simulations of LWR as well as VVER, HTR and fast reactors can be performed. The solver has been implemented in a fully encapsulated way, enabling it as a module to be readily integrated in other codes and platforms. In fact, it can be used either as a stand-alone nodal code or as a solver to accelerate the convergence of whole core pin-by-pin code systems. Verification of performance has shown that ANDES is a code with high order definition for whole core realistic nodal simulations. In this paper, the methodology developed and involved in ANDES is presented

An ANP approach for the stakeholder analysis in participatory environmental management. The case of Spanish wetland La Albufera

Trabajo presentado al International Symposium of the Analytic Hierarchy Process celebrado en washington (US) del 29 de junio al 2 de julio de 2014.The aim of this paper is to analyze the influence of the stakeholders in a participatory decision making process. For that, the relationships and influences among stakeholders involved in a specific environmental problem, namely rice straw management in the Natural Park of La Albufera, Valencia (Spain), have been studied using an Analytic Network Process approach. The main question we set is how to measure the influence among stakeholders. This a complex question in a real life problem, due to the difficulty for a stakeholder to answer the direct question: Who do you think exerts more influence on you when you have to solve a problem? In this work, we present a case study assuming that the information exchange is the way to measure the influence among the individuals in the network. We will use these data to solve an easy ANP model. This model is a first approach to prove the utility of ANP to measure the influences among stakeholders in a Social Network.N

An in-depth analysis of a TTO's objectives alignment within the university strategy: An ANP-based approach

[EN] This paper presents the application of the Analytic Network Process for the analysis of the contribution of the third mission action plans to the research transfer policies set by the University Governing Body. The model is applied to the case study of the Technology Transfer Offices (TTO) of the Universitat Politècnica de València (Spain). The paper develops a rigorous decision-making tool that helps TTO managers analyse the effectiveness of TTO activities and their degree of alignment with the institution¿s objectives. This work considers TTO managers¿ qualitative information and value judgments about the activities performed.This work has been funded by Universitat Politecnica de Valencia PAID-06-2011/2042. The translation of this paper has been funded by the Universitat Politecnica de Valencia.Aragonés-Beltrán, P.; Poveda Bautista, R.; Jiménez-Sáez, F. (2017). An in-depth analysis of a TTO's objectives alignment within the university strategy: An ANP-based approach. Journal of Engineering and Technology Management. 44:19-43. doi:10.1016/j.jengtecman.2017.03.002S19434

Selección de mercados para la exportación intracomunitaria de alcachofa en conserva mediante técnicas de decisión multicriterio discretas. Estudio comparativo

Trabajo presentado al XVI Congreso Internacional de Ingeniería de Proyectos (AEIPRO), celebrado en Valencia (España) del 11 al 13 de julio de 2012.[EN]: The object of this study is to determine the priorities for export and introduction into European Union countries canned the product of artichoke, specifically established as alternatives, Germany, France and Italy, in the case of Germany for its growing import market, and France and Italy, for its great tradition in the consumption of artichoke. The company is engaged in the manufacture of canned vegetables, for the study were taken into account the current economic situation affecting the European economic community and that will be vital for proper prioritization of the different alternatives. After identification and selection and appointment of expert decision maker down the 27 criteria, such as income per capita, dynamic import and consumption of canned artichokes, which are included within the following groups: 1) intra-Community transactions, 2)target market environment, 3) economic situation, 4) consumer Tradition, 5) Quality and environmental processes, 6) product Quality required.[ES]: En el contexto económico actual, las empresas dedicadas a la producción agrícola tienen que abrir nuevos mercados a la exportación. Las pequeñas y medianas empresas del sector no pueden abarcar todos los mercados potenciales y tienen que concentrar sus recursos en algunos mercados específicos. El objeto de este estudio es ayudar a una pequeña empresa de conservas vegetales a establecer las prioridades de introducción de sus productos en países de la unión europea. Se establecen como alternativas, Alemania, Francia e Italia, en el caso de Alemania por su creciente mercado importador, y Francia e Italia, por su gran tradición en el consumo de estos productos. Se trata de un problema de toma de decisiones complejo debido a los criterios que se han de tener en cuenta. Para ello, en este trabajo se propone el uso de diferentes técnicas de toma de decisiones multicriterio (AHP, ANP, PROMETHEE y TOPSIS), y se realiza un análisis comparativo de los resultados obtenidos.Peer reviewe

How to assess stakeholders' influence in project management? A proposal based on the Analytic Network Process

[EN] In this paper we present a methodology to measure stakeholders' influences within a project from the point of view of the Project Manager. It is a novel proposal for the definition of "influence" among stakeholders based on a multiperspective approach. The concept of influence is broken down into criteria, evaluating different aspects that together define an index which measures the influence of each stakeholder with respect to the rest of the project team. This index is calculated with the Analytic Network Process. The methodology has been applied to a maintenance project for the Spanish National Railway Infrastructure company. Results show that the most influential stakeholders are the Contractor and the Signaling systems provider accounting for 40% of the total influence. These results have helped the Project Manager to be aware of the two most influential stakeholders and set the guidelines for the stakeholder management in the future.Aragonés-Beltrán, P.; García-Melón, M.; Montesinos-Valera, J. (2017). How to assess stakeholders' influence in project management? A proposal based on the Analytic Network Process. International Journal of Project Management. 35(3):451-462. https://doi.org/10.1016/j.ijproman.2017.01.001S45146235

Análisis de la transmutación de Actínidos Minoritarios en un reactor rápido de sodio con modelo de carga homogéneo mediante el código MCNPX-CINDER

El reactor rápido refrigerado por sodio (SFR) constituye uno de los conceptos más prometedores de los seis considerados en la Generación IV de reactores nucleares, encontrándose actualmente en fase de investigación. En este marco surge el proyecto europeo CP ESFR (Collaborative Project for an European Sodium Fast Reactor) cuya finalidad es analizar los diversos desafíos y oportunidades que el desarrollo de este tipo de reactores plantea, ya sea en términos de seguridad, tecnología de sodio, capacidades transmutadoras, etc

Testing a Recent DEMATEL-Based Proposal to Simplify the Use of ANP

[EN] The Analytic Network Process (ANP) is a well-known multi-criteria decision method that allows the relationships between its elements to be incorporated into the model. The large number of questions to be answered is one of the main drawbacks of the method, since it is time consuming for decision makers and experts who participate in the decision process. A recent DEMATEL-based ANP proposal can significantly reduce the number and the complexity of questions. This proposal was simply exposed and lacked an experimental test with real cases. The fundamental objective of this work is to answer the question: Does it work? In this work, this new proposal is applied to 45 ANP cases published in the literature. Variants to the verified proposal have also been identified. The results obtained show that the values of the priorities and the ranks obtained with this new proposal are very similar to the results obtained with the ANP, reducing the number of questions required by 42% on average. Additionally, in this work you can find the compilation of the 45 ANP weighted supermatrices to use in your investigations.Schulze-González, E.; Pastor-Ferrando, J.; Aragonés-Beltrán, P. (2021). Testing a Recent DEMATEL-Based Proposal to Simplify the Use of ANP. Mathematics. 9(14):1-23. https://doi.org/10.3390/math9141605S12391

Selection of rail improvement projects using the Analytic Network Process

Trabajo presentado al XI International Symposium on the AHP celebrado en Nápoles (Italia) del 15 al 18 de Junio de 2011.In this artiele the applieation of the Analytie Network Process (ANP) to establish priorities arnong the portfolio of rail infrastructure rnaintenance, rehabilitation and improvernent projects in the area of Valencia (Spain) is presented. The problem is complex because of the large number and variety of projects to be considered and the great number of criteria that must be taken into account in the decision analysis process. The present work is a continuation of a previons research hased on the AHP model. The present study analyzes the different priority values of a particular group of projects obtained in ANP and AHP as well as changes in the weigbts of the criteria and the possibility of eliminating minor criteria from the model for the sake of simplicity.Peer Reviewe