Download or read book Core Physics of Pebble Bed High Temperature Nuclear Reactors written by and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Physics of High Temperature Reactors written by Luigi Massimo and published by Elsevier. This book was released on 2013-10-22 with total page 249 pages. Available in PDF, EPUB and Kindle. Book excerpt: Physics of High-Temperature Reactors focuses on the physics of high-temperature reactors (HTRs) and covers topics ranging from fuel cycles and refueling strategies to neutron cross-sections, transport and diffusion theory, and resonance absorption. Spectrum calculations and cross-section averaging are also discussed, along with the temperature coefficient and reactor control. Comprised of 16 chapters, this book begins with a general description of the HTR core as well as its performance limitations. The next chapter deals with general considerations about HTR physics, including quantities to be determined and optimized in the design of nuclear reactors. Potential scattering and resonance reactions between neutrons and atomic nuclei are then considered, together with basic aspects of transport and diffusion theory. Subsequent chapters explore methods for solving the diffusion equation; slowing-down and neutron thermalization in graphite; HTR core design, fuel management, and cost calculations; and core dynamics and accident analysis. The final chapter describes the sequence of reactor design calculations. This monograph is written primarily for students of HTR physics who are preparing to enter the field as well as technologists of other disciplines who are working on the system.

Download or read book The pebble bed high temperature reactor as a source of nuclear process heat written by and published by . This book was released on 1974 with total page 73 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The pebble bed high temperature reactor as a source of nuclear process heat written by and published by . This book was released on 1974 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Pebble Bed High Temperature Reactor as a Source of Nuclear Process Heat written by and published by . This book was released on 1974 with total page 73 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Optimized Core Design and Fuel Management of a Pebble bed Type Nuclear Reactor written by Brian Boer and published by . This book was released on 2008 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Very High Temperature Reactor (VHTR) has been selected by the international Generation IV research initiative as one of the six most promising nuclear reactor concepts that are expected to enter service in the second half of the 21st century. As one of the fourth generation nuclear reactors, the VHTR is characterized by high plant efficiency and a high fuel discharge burn-up level. More specifically, the (pebble-bed type) High Temperature Reactor (HTR) is known for its inherently safe characteristics, coming from a negative temperature reactivity feedback, a low power density and a large thermal inertia of the core.

Download or read book Pebble Bed Reactors Design Optimization Methods and Their Application to the Pebble Bed Fluoride Salt Cooled High Temperature Reactor PB FHR written by Anselmo Tomas Cisneros and published by . This book was released on 2013 with total page 859 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Fluoride salt cooled High temperature Reactor (FHR) is a class of advanced nuclear reactors that combine the robust coated particle fuel form from high temperature gas cooled reactors, direct reactor auxillary cooling system (DRACS) passive decay removal of liquid metal fast reactors, and the transparent, high volumetric heat capacitance liquid fluoride salt working fluids - flibe (33%7Li2F-67%BeF) - from molten salt reactors. This combination of fuel and coolant enables FHRs to operate in a high-temperature low-pressure design space that has beneficial safety and economic implications. In 2012, UC Berkeley was charged with developing a pre-conceptual design of a commercial prototype FHR - the Pebble Bed- Fluoride Salt Cooled High Temperature Reactor (PB-FHR) - as part of the Nuclear Energy University Programs' (NEUP) integrated research project. The Mark 1 design of the PB-FHR (Mk1 PB-FHR) is 236 MWt flibe cooled pebble bed nuclear heat source that drives an open-air Brayton combine-cycle power conversion system. The PB-FHR's pebble bed consists of a 19.8% enriched uranium fuel core surrounded by an inert graphite pebble reflector that shields the outer solid graphite reflector, core barrel and reactor vessel. The fuel reaches an average burnup of 178000 MWt-d/MT. The Mk1 PB-FHR exhibits strong negative temperature reactivity feedback from the fuel, graphite moderator and the flibe coolant but a small positive temperature reactivity feedback of the inner reflector and from the outer graphite pebble reflector. A novel neutronics and depletion methodology - the multiple burnup state methodology was developed for an accurate and efficient search for the equilibrium composition of an arbitrary continuously refueled pebble bed reactor core. The Burnup Equilibrium Analysis Utility (BEAU) computer program was developed to implement this methodology. BEAU was successfully benchmarked against published results generated with existing equilibrium depletion codes VSOP and PEBBED for a high temperature gas cooled pebble bed reactor. Three parametric studies were performed for exploring the design space of the PB-FHR -- to select a fuel design for the PB-FHR] to select a core configuration; and to optimize the PB-FHR design. These parametric studies investigated trends in the dependence of important reactor performance parameters such as burnup, temperature reactivity feedback, radiation damage, etc on the reactor design variables and attempted to understand the underlying reactor physics responsible for these trends. A pebble fuel parametric study determined that pebble fuel should be designed with a carbon to heavy metal ratio (C/HM) less than 400 to maintain negative coolant temperature reactivity coefficients. Seed and thorium blanket-, seed and inert pebble reflector- and seed only core configurations were investigated for annular FHR PBRs - the C/HM of the blanket pebbles and discharge burnup of the thorium blanket pebbles were additional design variable for core configurations with thorium blankets. Either a thorium blanket or graphite pebble reflector is required to shield the outer graphite reflector enough to extend its service lifetime to 60 EFPY. The fuel fabrication costs and long cycle lengths of the thorium blanket fuel limit the potential economic advantages of using a thorium blanket. Therefore, the seed and pebble reflector core configuration was adopted as the baseline core configuration. Multi-objective optimization with respect to economics was performed for the PB-FHR accounting for safety and other physical design constraints derived from the high-level safety regulatory criteria. These physical constraints were applied along in a design tool, Nuclear Application Value Estimator, that evaluated a simplified cash flow economics model based on estimates of reactor performance parameters calculated using correlations based on the results of parametric design studies for a specific PB-FHR design and a set of economic assumptions about the electricity market to evaluate the economic implications of design decisions. The optimal PB-FHR design - Mark 1 PB-FHR - is described along with a detailed summary of its performance characteristics including: the burnup, the burnup evolution, temperature reactivity coefficients, the power distribution, radiation damage distributions, control element worths, decay heat curves and tritium production rates. The Mk1 PB-FHR satisfies the PB-FHR safety criteria. The fuel, moderator (pebble core, pebble shell, graphite matrix, TRISO layers) and coolant have global negative temperature reactivity coefficients and the fuel temperatures are well within their limits.

Download or read book Advanced Core Design And Fuel Management For Pebble Bed Reactors written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A method for designing and optimizing recirculating pebble-bed reactor cores is presented. At the heart of the method is a new reactor physics computer code, PEBBED, which accurately and efficiently computes the neutronic and material properties of the asymptotic (equilibrium) fuel cycle. This core state is shown to be unique for a given core geometry, power level, discharge burnup, and fuel circulation policy. Fuel circulation in the pebble-bed can be described in terms of a few well?defined parameters and expressed as a recirculation matrix. The implementation of a few heat?transfer relations suitable for high-temperature gas-cooled reactors allows for the rapid estimation of thermal properties critical for safe operation. Thus, modeling and design optimization of a given pebble-bed core can be performed quickly and efficiently via the manipulation of a limited number key parameters. Automation of the optimization process is achieved by manipulation of these parameters using a genetic algorithm. The end result is an economical, passively safe, proliferation-resistant nuclear power plant.

Download or read book Molten Salt Reactors and Thorium Energy written by Thomas James Dolan and published by Elsevier. This book was released on 2024-01-25 with total page 1068 pages. Available in PDF, EPUB and Kindle. Book excerpt: Molten Salt Reactors and Thorium Energy, Second Edition is a fully updated comprehensive reference on the latest advances in MSR research and technology. Building on the successful first edition, Tom Dolan and the team of experts have fully updated the content to reflect the impressive advances from the last 5 years, ensuring this book continues to be the go-to reference on the topic. This new edition covers progress made in MSR design, details innovative experiments, and includes molten salt data, corrosion studies and deployment plans. The successful case studies section of the first edition have been removed, expanded, and fully updated, and are now published in a companion title called Global Case Studies on Molten Salt Reactors. Readers will gain a deep understanding of the advantages and challenges of MSR development and thorium fuel use, as well as step-by-step guidance on the latest in MSR reactor design. Each chapter provides a clear introduction, covers technical issues and includes examples and conclusions, while promoting the sustainability benefits throughout. - A fully updated comprehensive handbook on Molten Salt Reactors and Thorium Energy, written by a team of global experts - Covers MSR applications, technical issues, reactor types and reactor designs - Includes 3 brand new chapters which reflect the latest advances in research and technology since the first edition published - Presents case studies on molten salt reactors which aid in the transition to net zero by providing abundant clean, safe energy to complement wind and solar powe

Download or read book Fundamentals of Nuclear Reactor Physics written by Elmer E. Lewis and published by Elsevier. This book was released on 2008-01-18 with total page 311 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fundamentals of Nuclear Reactor Physics offers a one-semester treatment of the essentials of how the fission nuclear reactor works, the various approaches to the design of reactors, and their safe and efficient operation . It provides a clear, general overview of atomic physics from the standpoint of reactor functionality and design, including the sequence of fission reactions and their energy release. It provides in-depth discussion of neutron reactions, including neutron kinetics and the neutron energy spectrum, as well as neutron spatial distribution. It includes ample worked-out examples and over 100 end-of-chapter problems. Engineering students will find this applications-oriented approach, with many worked-out examples, more accessible and more meaningful as they aspire to become future nuclear engineers. - A clear, general overview of atomic physics from the standpoint of reactor functionality and design, including the sequence of fission reactions and their energy release - In-depth discussion of neutron reactions, including neutron kinetics and the neutron energy spectrum, as well as neutron spatial distribution - Ample worked-out examples and over 100 end-of-chapter problems - Full Solutions Manual

Download or read book Heat Transfer in Pebble Bed Nuclear Reactor Cores Cooled by Fluoride Salts written by Lakshana Ravindranath Huddar and published by . This book was released on 2016 with total page 165 pages. Available in PDF, EPUB and Kindle. Book excerpt: ABSTRACT Heat Transfer in Pebble-Bed Nuclear Reactor Cores Cooled by Fluoride Salts By Lakshana Ravindranath Huddar Doctor of Philosophy in Engineering - Nuclear Engineering University of California, Berkeley Professor Per F. Peterson, Chair With electricity demand predicted to rise by more than 50% within the next 20 years and a burgeoning world population requiring reliable emissions-free base-load electricity, can we design advanced nuclear reactors to help meet this challenge? At the University of California, Berkeley (UCB) Fluoride-salt-cooled High Temperature Reactors (FHR) are currently being investigated. FHRs are designed with better safety and economic characteristics than conventional light water reactors (LWR) currently in operation. These reactors operate at high temperature and low pressure making them more efficient and safer than LWRs. The pebble-bed FHR (PB-FHR) variant includes an annular nuclear reactor core that is filled with randomly packed pebble fuel. It is crucial to characterize the heat transfer within this unique geometry as this informs the safety limits of the reactor. The work presented in this dissertation focused on furthering the understanding of heat transfer in pebble-bed nuclear reactor cores using fluoride salts as a coolant. This was done through experimental, analytical and computational techniques. A complex nuclear system with a coolant that has never previously been in commercial use requires experimental data that can directly inform aspects of its design. It is important to isolate heat transfer phenomena in order to understand the underlying physics in the context of the PB-FHR, as well as to make decisions about further experimental work that needs to be done in support of developing the PB-FHR. Certain organic oils can simulate the heat transfer behaviour of the fluoride salt if relevant non-dimensional parameters are matched. The advantage of this method is that experiments can be done at a much lower temperature and at a smaller geometric scale compared to FHRs, thereby lowering costs. In this dissertation, experiments were designed and performed to collect data demonstrating similitude. The limitations of these experiments were also elucidated by underlining key distortions between the experimental and the prototypical conditions. This dissertation is broadly split into four parts. Firstly, the heat transfer phenomenology in the PB-FHR core was outlined. Although the viscous dissipation term and the thermal diffusion term (including thermal dispersion) were similar in magnitude, they were overshadowed by the advection term which was about 104 times bigger during normal operation and 105 times bigger during accident transients in which natural circulation becomes the main mode of fluid flow. Thus it is safe to neglect the viscous dissipation and the thermal diffusion terms in the PB-FHR core without a significant loss of accuracy. Secondly, separate effects tests (SET) were performed using simulant oils, and the results were compared to the prototypical conditions using flinak as the fluoride salt. The main purpose of these experiments was to study natural convection heat transfer and identify any distortions between the two cases. An isolated copper sphere was immersed in flinak and a parallel experiment was performed using simulant oil. A large discrepancy between the flinak and the oil was noted, due to distortions from assuming quasi-steady state conditions. A steady state experiment using a cylindrical heater immersed in oil was also performed, and the results compared to a similar experiment done at Oak Ridge National Laboratory (ORNL) using flinak. The Nusselt numbers matched within 10% for laminar flows. This supports the conclusion that natural convection similitude does exist for oils used in scaled experiments, allowing natural convection data to be used for for FHR and MSR modeling. This is important, due to the lack of significant experimental data showing natural convection in fluoride salts, so these SETs add to the overall understanding of their heat transfer properties. With the knowledge of the distortions between the oil and the salt, an experiment to measure heat transfer coefficients within a pebble-bed test section was designed, constructed and performed. Oil was pumped through a test section filled with randomly packed copper spheres. The temperature of the oil was pulsed at a constant frequency, which caused a temperature difference between the pebbles and the oil. An excellent match was found between the measured heat transfer coefficients and the literature. This data provides an essential closure parameter for multiphysics modeling of the PB-FHR. Using frequency response techniques in scaled experiments is an innovative approach for extracting dynamic responses to coolant-structure interactions. Finally, an integrated model of the passive decay heat removal system was presented using Flownex and the simulations compared to experimental data. A good match was found with the data, which was within 14%. The work presented in this dissertation shows fundamental details on heat transfer in the PB-FHR core using experimental data and simulations, leading us closer to developing advanced nuclear reactors that can later be commercialized. Advanced nuclear reactors such as the PB-FHR have immense potential in reducing greenhouse gas emissions and combating climate change while being exceedingly safe and providing reliable electricity.

Download or read book Very High Temperature Reactor VHTR Deep Burn Core and Fuel Analysis Complete Design Selection for the Pebble Bed Reactor written by and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Deep-Burn (DB) concept focuses on the destruction of transuranic nuclides from used light water reactor fuel. These transuranic nuclides are incorporated into TRISO coated fuel particles and used in gas-cooled reactors with the aim of a fractional fuel burnup of 60 to 70% in fissions per initial metal atom (FIMA). This high performance is expected through the use of multiple recirculation passes of the fuel in pebble form without any physical or chemical changes between passes. In particular, the concept does not call for reprocessing of the fuel between passes. In principle, the DB pebble bed concept employs the same reactor designs as the presently envisioned low-enriched uranium core designs, such as the 400 MWth Pebble Bed Modular Reactor (PBMR-400). Although it has been shown in the previous Fiscal Year (2009) that a PuO2 fueled pebble bed reactor concept is viable, achieving a high fuel burnup, while remaining within safety-imposed prescribed operational limits for fuel temperature, power peaking and temperature reactivity feedback coefficients for the entire temperature range, is challenging. The presence of the isotopes 239-Pu, 240-Pu and 241-Pu that have resonances in the thermal energy range significantly modifies the neutron thermal energy spectrum as compared to a" standard," UO2-fueled core. Therefore, the DB pebble bed core exhibits a relatively hard neutron energy spectrum. However, regions within the pebble bed that are near the graphite reflectors experience a locally softer spectrum. This can lead to power and temperature peaking in these regions. Furthermore, a shift of the thermal energy spectrum with increasing temperature can lead to increased absorption in the resonances of the fissile Pu isotopes. This can lead to a positive temperature reactivity coefficient for the graphite moderator under certain operating conditions. The effort of this task in FY 2010 has focused on the optimization of the core to maximize the pebble discharge burnup level, while retaining its inherent safety characteristics. Using generic pebble bed reactor cores, this task will perform physics calculations to evaluate the capabilities of the pebble bed reactor to perform utilization and destruction of LWR used-fuel transuranics. The task will use established benchmarked models, and will introduce modeling advancements appropriate to the nature of the fuel considered (high TRU content and high burn-up).

Download or read book Handbook of Generation IV Nuclear Reactors written by Igor Pioro and published by Woodhead Publishing. This book was released on 2022-12-07 with total page 1112 pages. Available in PDF, EPUB and Kindle. Book excerpt: Handbook of Generation IV Nuclear Reactors, Second Edition is a fully revised and updated comprehensive resource on the latest research and advances in generation IV nuclear reactor concepts. Editor Igor Pioro and his team of expert contributors have updated every chapter to reflect advances in the field since the first edition published in 2016. The book teaches the reader about available technologies, future prospects and the feasibility of each concept presented, equipping them users with a strong skillset which they can apply to their own work and research. - Provides a fully updated, revised and comprehensive handbook dedicated entirely to generation IV nuclear reactors - Includes new trends and developments since the first publication, as well as brand new case studies and appendices - Covers the latest research, developments and design information surrounding generation IV nuclear reactors

Download or read book Advances in High Temperature Gas Cooled Reactor Fuel Technology written by International Atomic Energy Agency and published by . This book was released on 2012-06 with total page 639 pages. Available in PDF, EPUB and Kindle. Book excerpt: This publication reports on the results of a coordinated research project on advances in high temperature gas cooled reactor (HTGR) fuel technology and describes the findings of research activities on coated particle developments. These comprise two specific benchmark exercises with the application of HTGR fuel performance and fission product release codes, which helped compare the quality and validity of the computer models against experimental data. The project participants also examined techniques for fuel characterization and advanced quality assessment/quality control. The key exercise included a round-robin experimental study on the measurements of fuel kernel and particle coating properties of recent Korean, South African and US coated particle productions applying the respective qualification measures of each participating Member State. The summary report documents the results and conclusions achieved by the project and underlines the added value to contemporary knowledge on HTGR fuel.

Download or read book PHYSICS OF THE PEBBLE BED HIGH TEMPERATURE REACTOR IN MASSIVE WATER INGRESS ACCIDENTS IN GERMAN written by W. Scherer and published by . This book was released on 1989 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Handbook of Small Modular Nuclear Reactors written by Daniel T. Ingersoll and published by Woodhead Publishing. This book was released on 2020-10-22 with total page 648 pages. Available in PDF, EPUB and Kindle. Book excerpt: Handbook of Small Modular Nuclear Reactors, Second Edition is a fully updated comprehensive reference on Small Modular Reactors (SMRs), which reflects the latest research and technological advances in the field from the last five years. Editors Daniel T. Ingersoll and Mario D. Carelli, along with their team of expert contributors, combine their wealth of collective experience to update this comprehensive handbook that provides the reader with all required knowledge on SMRs, expanding on the rapidly growing interest and development of SMRs around the globe. This book begins with an introduction to SMRs for power generation, an overview of international developments, and an analysis of Integral Pressurized Water Reactors as a popular class of SMRs. The second part of the book is dedicated to SMR technologies, including physics, components, I&C, human-system interfaces and safety aspects. Part three discusses the implementation of SMRs, covering economic factors, construction methods, hybrid energy systems and licensing considerations. The fourth part of the book provides an in-depth analysis of SMR R&D and deployment of SMRs within eight countries, including the United States, Republic of Korea, Russia, China, Argentina, and Japan. This edition includes brand new content on the United Kingdom and Canada, where interests in SMRs have increased considerably since the first edition was published. The final part of the book adds a new analysis of the global SMR market and concludes with a perspective on SMR benefits to developing economies. This authoritative and practical handbook benefits engineers, designers, operators, and regulators working in nuclear energy, as well as academics and graduate students researching nuclear reactor technologies. Presents the latest research on SMR technologies and global developments Includes new case study chapters on the United Kingdom and Canada and a chapter on global SMR markets Discusses new technologies such as floating SMRs and molten salt SMRs

Download or read book The Pebble Bed High Temperature Reactor as a Source of Nuclear Process Heat written by and published by . This book was released on 1974 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt: