Download or read book HTR 2014 Paper Comparison of Fission Product Release Predictions Using PARFUME with Results from the AGR 1 Safety Tests written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Safety tests were conducted on fourteen fuel compacts from AGR-1, the first irradiation experiment of the Advanced Gas Reactor (AGR) Fuel Development and Qualification program, at temperatures ranging from 1600 to 1800°C to determine fission product release at temperatures that bound reactor accident conditions. The PARFUME (PARticle FUel ModEl) code was used to predict the release of fission products silver, cesium, strontium, and krypton from fuel compacts containing tristructural isotropic (TRISO) coated particles during the safety tests, and the predicted values were compared with experimental results. Preliminary comparisons between PARFUME predictions and post-irradiation examination (PIE) results of the safety tests show an overall over-prediction of the fractional release of these fission products, which is largely attributed to an over-estimation of the diffusivities used in the modeling of fission product transport in TRISO-coated particles. Correction factors to these diffusivities were assessed for silver and cesium in order to enable a better match between the modeling predictions and the safety testing results. In the case of strontium, correction factors could not be assessed because potential release during the safety tests could not be distinguished from matrix content released during irradiation. In the case of krypton, all the coating layers are partly retentive and the available data did not allow to determine their respective retention powers, hence preventing to derive any correction factors.

Download or read book HTR 2014 Paper Comparison of Fission Product Release Predictions Using PARFUME with Results from the AGR 1 Irradiation Experiment written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The PARFUME (PARticle FUel ModEl) code was used to predict fission product release from tristructural isotropic (TRISO) coated fuel particles and compacts during the first irradiation experiment (AGR-1) of the Advanced Gas Reactor Fuel Development and Qualification program. The PARFUME model for the AGR-1 experiment used the fuel compact volume average temperature for each of the 620 days of irradiation to calculate the release of fission products silver, cesium, and strontium from a representative particle for a select number of AGR-1 compacts. Post-irradiation examination (PIE) measurements provided data on release of fission products from fuel compacts and fuel particles, and retention of fission products in the compacts outside of the SiC layer. PARFUME-predicted fractional release of these fission products was determined and compared to the PIE measurements. Results show an overall over-prediction of the fractional release of cesium by PARFUME. For particles with failed silicon carbide (SiC) layers, the over-prediction is by a factor of about two, corresponding to an over-estimation of the diffusivity in uranium oxycarbide (UCO) by a factor of about 100. For intact particles, whose release is much lower, the over-prediction is by an average of about an order of magnitude, which could additionally be attributed to an over-estimated diffusivity in SiC by about 30%. The release of strontium from intact particles is also over-estimated by PARFUME, which also points towards an over-estimated diffusivity of strontium in either SiC or UCO, or possibly both. The measured strontium fractional release from intact particles varied considerably from compact to compact, making it difficult to assess the effective over-estimation of the diffusivities. Furthermore, the release of strontium from particles with failed SiC is difficult to observe experimentally due to the release from intact particles, preventing any conclusions to be made on the accuracy or validity of the PARFUME predictions and the modeled diffusivity of strontium in UCO. In the case of silver, the comparisons between PARFUME and PIE are better than for cesium and strontium. They show a trend of over-prediction at low burnup and under-prediction at high burnup. PARFUME has limitations in the modeling of the temporal and spatial distributions of the temperature and burnup across the compacts, which affects the accuracy of its predictions. Nevertheless, the comparisons lie in the same order of magnitude.

Download or read book Comparison of Fission Product Release Predictions Using PARFUME with Results from the AGR 1 Safety Tests 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 Comparison of Fission Product Release Predictions Using PARFUME with Results from the AGR 1 Irradiation Experiment written by and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This report documents comparisons between post-irradiation examination measurements and model predictions of silver (Ag), cesium (Cs), and strontium (Sr) release from selected tristructural isotropic (TRISO) fuel particles and compacts during the first irradiation test of the Advanced Gas Reactor program that occurred from December 2006 to November 2009 in the Advanced Test Reactor (ATR) at Idaho National Laboratory (INL). The modeling was performed using the particle fuel model computer code PARFUME (PARticle FUel ModEl) developed at INL. PARFUME is an advanced gas-cooled reactor fuel performance modeling and analysis code (Miller 2009). It has been developed as an integrated mechanistic code that evaluates the thermal, mechanical, and physico-chemical behavior of fuel particles during irradiation to determine the failure probability of a population of fuel particles given the particle-to-particle statistical variations in physical dimensions and material properties that arise from the fuel fabrication process, accounting for all viable mechanisms that can lead to particle failure. The code also determines the diffusion of fission products from the fuel through the particle coating layers, and through the fuel matrix to the coolant boundary. The subsequent release of fission products is calculated at the compact level (release of fission products from the compact) but it can be assessed at the particle level by adjusting the diffusivity in the fuel matrix to very high values. Furthermore, the diffusivity of each layer can be individually set to a high value (typically 10-6 m2/s) to simulate a failed layer with no capability of fission product retention. In this study, the comparison to PIE focused on fission product release and because of the lack of failure in the irradiation, the probability of particle failure was not calculated. During the AGR-1 irradiation campaign, the fuel kernel produced and released fission products, which migrated through the successive layers of the TRISO-coated particle and potentially through the compact matrix. The release of these fission products was measured in PIE and modeled with PARFUME.

Download or read book A comparison of the fission product release predictions of MATREL and FASTGRASS during a severe reactor accident written by A. J. Manley and published by . This book was released on 1985 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Modeling of Fission Product Release from HTR high Temperature Reactor Fuel for Risk Analyses written by and published by . This book was released on 1989 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The US and FRG have developed methodologies to determine the performance of and fission product release from TRISO-coated fuel particles under postulated accident conditions. The paper presents a qualitative and quantitative comparison of US and FRG models. The models are those used by General Atomics (GA) and by the German Nuclear Research Center at Juelich (KFA/ISF). A benchmark calculation was performed for fuel temperatures predicted for the US Department of Energy sponsored Modular High Temperature Gas Cooled Reactor (MHTGR). Good agreement in the benchmark calculations supports the on-going efforts to verify and validate the independently developed codes of GA and KFA/ISF. This work was performed under the US/FRG Umbrella Agreement for Cooperation on Gas Cooled Reactor Development. 6 refs., 3 figs., 3 tabs.

Download or read book Kinetics of Fission Product Release Prior to Fuel Slumping written by and published by . This book was released on 1987 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper describes the primary physical/chemical models recently incorporated into a mechanistic code (FASTGRASS) for the estimation of fission product release from fuel, and compares predicted results with test data. The theory of noble gas behavior is discussed in relation to its effect on the release behavior of I, Cs, Te, Ba, and Sr. The behavior of these fission products in the presence of fuel liquefaction/dissolution and oxidation grain-growth phenomena is presented, as is the chemistry of Sr, Ba, I, and Cs. Comparison of code predictions with data indicates the following trends. Fission product release behavior from solid strongly depends on fuel microstructure, irradiation history, time at temperature, and internal fuel rod chemistry. Fuel liquefaction/dissolution, fracturing, and oxidation also exert a pronounced effect on release during fuel rod degradation. For very low burnup fuel appreciable fission product retention in previously liquefied fuel can occur due to the low concentration of fission products, and the limited growth of bubbles in the liquefied material. 24 refs., 13 figs., 9 tabs.

Download or read book Data Summary Report for Fission Product Release Test VI 1 written by and published by . This book was released on 1989 with total page 59 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Assessment of Improved Fission product Transport Models in VICTORIA Against the ORNL HI and VI Tests written by and published by . This book was released on 1991 with total page 23 pages. Available in PDF, EPUB and Kindle. Book excerpt: New models for the release of fission-products from fuel have recently been incorporated into a comprehensive code, VICTORIA, for the prediction of radionuclide behavior under severe reactor accident conditions as an alternative to a simple Booth diffusion calculation. It is widely known that the Booth model has severe limitations when used under conditions of changing temperature and power. A new transport model based on a two node diffusive flow formulation has been implemented into VICTORIA. In addition to the diffusive flow model, other mechanisms such as grain growth, grain boundary sweeping and intergranular bubble behavior are taken into account. These physically based models focus on fission-product behavior in intact fuel geometries. While the VICTORIA program is primarily concerned with the behavior of severely degraded fuel geometries, the capability for accurately characterizing fission-product release from intact fuel must be demonstrated before other geometries can be reliably modeled. Results of VICTORIA simulations are compared with the results of in-cell heating tests on irradiated fuel. The fission-product transport models involved in these simulations are assessed and their predictive capability examined. 10 refs., 7 figs., 2 tabs.

Download or read book Comparison of fission gas release data with Supatrice 2 predictions at S G H W R fuel ratings written by C. B. Cowking and published by . This book was released on 1968 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Heterogeneous Photocatalysis Using Inorganic Semiconductor Solids written by Umar Ibrahim Gaya and published by Springer Science & Business Media. This book was released on 2013-11-08 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book underscores the essential principles of photocatalysis and provides an update on its scientific foundations, research advances, and current opinions, and interpretations. It consists of an introduction to the concepts that form the backbone of photocatalysis, from the principles of solid-state chemistry and physics to the role of reactive oxidizing species. Having recognised the organic link with chemical kinetics, part of the book describes kinetic concepts as they apply to photocatalysis. The dependence of rate on the reaction conditions and parameters is detailed, the retrospective and prospective aspects of the mechanism of photocatalysis are highlighted, and the adsorption models, photocatalytic rate expressions, and kinetic disguises are examined. This book also discusses the structure, property, and activity relationship of prototypical semiconductor photocatalysts and reviews how to extend their spectral absorption to the visible region to enable the effective use of visible solar spectrum. Lastly, it presents strategies for deriving substantially improved photoactivity from semiconductor materials to support the latest applications and potential trends.

Download or read book Management of Nuclear Power Plant Projects written by IAEA and published by International Atomic Energy Agency. This book was released on 2020-11-25 with total page 221 pages. Available in PDF, EPUB and Kindle. Book excerpt: Member States intending to introduce a nuclear power programme will need to pass through several phases during the implementation. Experience shows that careful planning of the objectives, roles, responsibilities, interfaces and tasks to be carried out in different phases of a nuclear project is important for success. This publication presents a harmonized approach that may be used to structure the owner/operator management system and establish and manage nuclear projects and their development activities irrespective of the adopted approach. It has been developed from shared management practices and consolidated experiences provided by nuclear project management specialists through a series of workshops and working groups organized by the IAEA. The resultant publication presents a useful framework for the management of nuclear projects from initiation to closeout and captures international best practices.

Download or read book Thermal and Flow Design of Helium cooled Reactors written by Gilbert Melese and published by . This book was released on 1984 with total page 444 pages. Available in PDF, EPUB and Kindle. Book excerpt: This source book provides both an overview of gas-cooled reactors and a detailed look at the high-temperature gas-cooled reactor (HTGR). Taking a worldwide perspective, this book reviews the early development of the HTGR and explores potential future development and applications.

Download or read book Fission Product Processes In Reactor Accidents written by J. T. Rogers and published by CRC Press. This book was released on 2020-12-17 with total page 883 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Three Mile Island and Chernobyl nuclear incidents emphasized the need for the world-wide nuclear community to cooperate further and exchange the results of research in this field in the most open and effective manner. Recognizing the roles of heat and mass transfer in all aspects of fission-product behavior in sever reactor accidents, the Executive Committee of the International Centre for Heat and Mass Transfer organized a Seminar on Fission Product Transport Processes in Reactor Accidents. This book contains the eleven of the lectures and all the papers presented at the seminar along with four invited papers that were not presented and a summary of the closing session.

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 Complex Concentrated Alloys CCAs written by Sundeep Mukherjee and published by MDPI. This book was released on 2020-11-04 with total page 278 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a collection of several unique articles on the current state of research on complex concentrated alloys, as well as their compelling future opportunities in wide ranging applications. Complex concentrated alloys consist of multiple principal elements and represent a new paradigm in structural alloy design. They show a range of exceptional properties that are unachievable in conventional alloys, including high strength–ductility combination, resistance to oxidation, corrosion/wear resistance, and excellent high-temperature properties. The research articles, reviews, and perspectives are intended to provide a wholistic view of this multidisciplinary subject of interest to scientists and engineers.

Download or read book Zeolites and Metal organic Frameworks written by Vincent Blay and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book examines Zeolites and Metal-Organic Frameworks. It explains the different synthetic routes available to prepare these materials, and examines how they are used by science and industry.