Modelling Of Nuclear Reactor Multi Physics

Modelling of Nuclear Reactor Multiphysics: From Local Balance Equations to Macroscopic Models in Neutronics and Thermal-Hydraulics is an accessible guide to the advanced methods used to model nuclear reactor systems. The book addresses the frontier discipline of neutronic/thermal-hydraulic modelling of nuclear reactor cores, presenting the main techniques in a generic manner and for practical reactor calculations.The modelling of nuclear reactor systems is one of the most challenging tasks in complex system modelling, due to the many different scales and intertwined physical phenomena involved. The nuclear industry as well as the research institutes and universities heavily rely on the use of complex numerical codes. All the commercial codes are based on using different numerical tools for resolving the various physical fields, and to some extent the different scales, whereas the latest research platforms attempt to adopt a more integrated approach in resolving multiple scales and fields of physics. The book presents the main algorithms used in such codes for neutronic and thermal-hydraulic modelling, providing the details of the underlying methods, together with their assumptions and limitations. Because of the rapidly expanding use of coupled calculations for performing safety analyses, the analysists should be equally knowledgeable in all fields (i.e. neutron transport, fluid dynamics, heat transfer).The first chapter introduces the book’s subject matter and explains how to use its digital resources and interactive features. The following chapter derives the governing equations for neutron transport, fluid transport, and heat transfer, so that readers not familiar with any of these fields can comprehend the book without difficulty. The book thereafter examines the peculiarities of nuclear reactor systems and provides an overview of the relevant modelling strategies. Computational methods for neutron transport, first at the cell and assembly levels, then at the core level, and for one-/two-phase flow transport and heat transfer are treated in depth in respective chapters. The coupling between neutron transport solvers and thermal-hydraulic solvers for coarse mesh macroscopic models is given particular attention in a dedicated chapter. The final chapter summarizes the main techniques presented in the book and their interrelation, then explores beyond state-of-the-art modelling techniques relying on more integrated approaches. Covers neutron transport, fluid dynamics, and heat transfer, and their interdependence, in one reference Analyses the emerging area of multi-physics and multi-scale reactor modelling Contains 71 short videos explaining the key concepts and 77 interactive quizzes allowing the readers to test their understanding

A nuclear reactor operates in an environment where complex multi-physics and multi-scale phenomena exist, and it requires consideration of coupling among neutronics, thermal hydraulics, fuel performance, chemical dynamics, and coupling between the reactor core and first circuit. Safe, reliable, and economical operation can be achieved by leveraging high-fidelity numerical simulation, and proper considerations for coupling among different physics and required to provide powerful numerical simulation tools. In the past simplistic models for some of the physics phenomena are used, with the recent development of advanced numerical methods, software design, and high-performance computing power, the appeal of multi-physics and multi-scale modeling and simulation has been broadened.

Multi-Physics Modelling (MPM) is an innovative simulation technique that looks very promising for the employment in the field of nuclear engineering as an integrative analysis support in the design development of current and innovative nuclear reactors. This book presents a Multi-Physics Modelling (MPM) approach to the analysis of nuclear reactor core behaviour, developed to study the coupling between neutronics and thermo-hydrodynamics. Reference is made to the Molten Salt Reactor, one of the innovative nuclear systems under development in the framework of the Generation IV International Forum, but the same methodology can be applied to other reactor systems.

Verification, Validation and Uncertainty Quantification in Multi-Physics Modeling of Nuclear Reactors is a key reference for those tasked with ensuring the credibility and reliability of engineering models and simulations for the nuclear industry and nuclear energy research. Sections discuss simulation challenges and revise key definitions, concepts and terminology. Chapters cover solution verification, the frontier discipline of multi-physics coupling verification, model validation and its applications to single and multi-scale models, and uncertainty quantification. This essential guide will greatly assist engineers, scientists, regulators and students in applying rigorous verification, validation and uncertainty quantification methodologies to the M&S tools used in the industry. The book contains a strong focus on the verification and validation procedures required for the emerging multi-physics M&S tools that have great potential for use in the licensing of new reactors, as well as for power uprating and life extensions of operating reactors. Uniquely--and crucially for nuclear engineers--demonstrates the application of verification, validation and uncertainty methodologies to the modeling and simulation (M&S) of nuclear reactors Equips the reader to develop a rigorously defensible validation process irrespective of the particular M&S tool used Brings the audience up-to-speed on validation methods for traditional M&S tools Extends the discussion to the emerging area of validation of multi-physics and multi-scale nuclear reactor simulations

Experimental Nuclear Reactor Analysis: Theory, Numerical Models and Experimental Analysis presents a consolidated resource on reactor analysis, comprising theoretical concepts of reactor physics, dynamics and thermal-hydraulics. Each element is applied to predict the behaviour of the TRIGA test reactor and its validation with the experimental data. Edited by Dr. Antonio Cammi and written by a team of expert contributors, this book is divided into three parts which provide the reader with a very thorough understanding of the different facets of nuclear reactor analysis. Part one presents various theoretical aspects which are required for the development of a computational model and experimental activities such as nuclear reactor physics, dynamics and control, and nuclear thermal hydraulics. The second part considers the concepts discussed in the first part, but applies them to develop computational tools for modelling the thermal-hydraulic and neutronic behaviour of reactors. The third part explores experiments designed to verify the results of computational models presented, along with a detailed description and analysis of the obtained results. This book serves as a complete guide to reactor analysis providing important theoretical background followed by a more advanced exploration and analysis of the experimental procedure and applications. Where readers do not have access to a test facility, the knowledge and practical understanding obtained from this book will ensure they are equipped with a very detailed insight and understanding of experimental reactor analysis, ready to apply to their own research and professional projects. Includes coverage of the computational models for the prediction of nuclear reactor neutronics and thermal-hydraulics Presents a description of experimental setup and procedure using TRIGA reactor and detailed analysis of obtained results and validation of computational predictions Contains exercises and applications throughout to deepen knowledge and understanding

Control analysis and design of large nuclear reactors requires a suitable mathematical model representing the steady state and dynamic behavior of the reactor with reasonable accuracy. This task is, however, quite challenging because of several complex dynamic phenomena existing in a reactor. Quite often, the models developed would be of prohibitively large order, non-linear and of complex structure not readily amenable for control studies. Moreover, the existence of simultaneously occurring dynamic variations at different speeds makes the mathematical model susceptible to numerical ill-conditioning, inhibiting direct application of standard control techniques. This monograph introduces a technique for mathematical modeling of large nuclear reactors in the framework of multi-point kinetics, to obtain a comparatively smaller order model in standard state space form thus overcoming these difficulties. It further brings in innovative methods for controller design for systems exhibiting multi-time-scale property, with emphasis on three-time-scale systems.

This volume represents the second of our occasional departures from the format of an annual review series, being devoted to one coherent topic. We have the pleasure therefore in presenting a concerted sequence of articles on the use of Simulators for Nuclear Power. An essential attribute of a quantified engineer in any discipline is to be able to model and predict, i.e. to analyze, the behaviour of the subject under scrutiny. Simulation goes, one would argue, a step further. The engineer providing a simulator takes a broader view of the system studied and makes the analysis available to a wider audience. Hence simulation may have a part to play in design but also in operation, in accident studies and also in training. It leads to synthesis as well as analysis. There is no doubt that the massive scale and the economic investment implied in nuclear power programmes demands an increased infra-structure in licensing and training as well as in design and operation. The simulator is a cheap alter native - admittedly cheap only in relative terms - but also perhaps an essential method of providing realistic experience with negligible or at least small risk. Nuclear power therefore has led to a wide range of simulators. At the same time we would not overlook the sub stantial role played by simulators in say the aero-industry; indeed the ergonomic and psychological studies associated with that industry hold many lessons.

This book contains selected papers of the 11th OpenFOAM® Workshop that was held in Guimarães, Portugal, June 26 - 30, 2016. The 11th OpenFOAM® Workshop had more than 140 technical/scientific presentations and 30 courses, and was attended by circa 300 individuals, representing 180 institutions and 30 countries, from all continents. The OpenFOAM® Workshop provided a forum for researchers, industrial users, software developers, consultants and academics working with OpenFOAM® technology. The central part of the Workshop was the two-day conference, where presentations and posters on industrial applications and academic research were shown. OpenFOAM® (Open Source Field Operation and Manipulation) is a free, open source computational toolbox that has a larger user base across most areas of engineering and science, from both commercial and academic organizations. As a technology, OpenFOAM® provides an extensive range of features to solve anything from complex fluid flows involving chemical reactions, turbulence and heat transfer, to solid dynamics and electromagnetics, among several others. Additionally, the OpenFOAM technology offers complete freedom to customize and extend its functionalities.