Download or read book On the Extension of Modern Best estimate Plus Uncertainy Methodologies to Future Fast Reactor and Advanced Fuel Licensing Initial Evaluation of Issues written by and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Closing the fuel cycle is the major technical challenge to expanding nuclear energy to meet the world's need for benign, environmentally safe electrical power. Closing the fuel cycle means getting the maximum amount of energy possible out of uranium fuel while in turn minimizing the amount of high-level waste that must be stored. DOE's Advance Fuel Cycle Initiative (AFCI) program addresses this challenge by recycling the transuranic (TRU) isotopes contained in spent nuclear fuel; recycling, in turn, minimizes the amount of high-level waste that would require storage in repositories. Developing new fuels and the plants that burn them is a lengthy and expensive process, typically spanning a period of two decades from concept to final licensing. A unique challenge to meeting the AFCI objectives in this area is that the experimental database is seriously incomplete. As such, using a traditional, heavily empirical approach to develop and qualify fuels and plant operation over the operational conditions of a AFCI plant will be very challenging, if not impossible, within the expected schedule and budgetary constraints. To address this concern AFCI has launched an advanced modeling and simulation (M & S) approach to revolutionize fuel development and fast reactor design. This new approach is predicated upon transferring the recent advances in computational sciences and computer technologies into the development of these program elements. The licensing process that has historically been used by the NRC for fuels qualification is based upon using a large body of experimental work to qualify and license a new fuel. If a modeling and simulation approach with more directed experimentation is to be considered as an alternative approach for licensing, then a framework needs to be developed that can be agreed to with the NRC early in the developmental process. The use of modeling and simulation as a means of demonstrating that a design can meet NRC requirements is not new and has precedence in the NRC. The method is generically referred to as a 'Best Estimate plus Uncertainty' approach (BE+U), since the goal of the methodology is to compare the model value (best estimate) plus any uncertainty to a figure of merit like cladding temperature. The challenges for extending the BE+U (1) method for fuel qualification for an Advanced Reactor Fuel are driven by: schedule, the need for data, the data sufficiency, the identification of important phenomenon, the process of validation (with focus on the multi-scale model), and the need to produce and extended best estimate plus uncertainty methodology. This paper examines these issues an offers up a proposed set of methods that extend the current BE+U methodology address most if not all of these challenges.
Download or read book Improved Best Estimate Plus Uncertainty Methodology Including Advanced Validation Concepts to License Evolving Nuclear Reactors written by and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Many evolving nuclear energy programs plan to use advanced predictive multi-scale multi-physics simulation and modeling capabilities to reduce cost and time from design through licensing. Historically, the role of experiments was primary tool for design and understanding of nuclear system behavior while modeling and simulation played the subordinate role of supporting experiments. In the new era of multi-scale multi-physics computational based technology development, the experiments will still be needed but they will be performed at different scales to calibrate and validate models leading predictive simulations. Cost saving goals of programs will require us to minimize the required number of validation experiments. Utilization of more multi-scale multi-physics models introduces complexities in the validation of predictive tools. Traditional methodologies will have to be modified to address these arising issues. This paper lays out the basic aspects of a methodology that can be potentially used to address these new challenges in design and licensing of evolving nuclear technology programs. The main components of the proposed methodology are verification, validation, calibration, and uncertainty quantification. An enhanced calibration concept is introduced and is accomplished through data assimilation. The goal is to enable best-estimate prediction of system behaviors in both normal and safety related environments. To achieve this goal requires the additional steps of estimating the domain of validation and quantification of uncertainties that allow for extension of results to areas of the validation domain that are not directly tested with experiments, which might include extension of the modeling and simulation (M & S) capabilities for application to full-scale systems. The new methodology suggests a formalism to quantify an adequate level of validation (predictive maturity) with respect to required selective data so that required testing can be minimized for cost saving purposes by showing further testing wold not enhance the quality of the validation of predictive tools. The proposed methodology is at a conceptual level. When matured and if considered favorably by the stakeholders, it could serve as a new framework for the next generation of the best estimate plus uncertainty licensing methodology that USNRC developed previously. In order to come to that level of maturity it is necessary to communicate the methodology to scientific, design and regulatory stakeholders for discussion and debates. This paper is the first step to establish this communication.
Download or read book Safety Margins of Operating Rectors written by M. Antila and published by International Atomic Energy Agency. This book was released on 2003 with total page 145 pages. Available in PDF, EPUB and Kindle. Book excerpt: This TECDOC deals with a basic concept of safety margins and their role in assuring safety of nuclear Installations. The document describes capabilities of thermal hydraulic computer codes used to determine safety margins, evaluation of uncertainties, methods for safety margin evaluation and utilization of safety margins in operation and modifications of nuclear power plants.
Download or read book IAEA Regional Workshop on Application of Best Estimate Plus Uncertainty BEPU analyses Methods in Nuclear Safety written by IAEA Regional Workshop on Application of Best Estimate plus Uncertainty (BEPU) Analyses Methods in Nuclear Safety and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Bulletin of the Atomic Scientists written by and published by . This book was released on 1953-05 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Bulletin of the Atomic Scientists is the premier public resource on scientific and technological developments that impact global security. Founded by Manhattan Project Scientists, the Bulletin's iconic "Doomsday Clock" stimulates solutions for a safer world.
Download or read book Bulletin of the Atomic Scientists written by and published by . This book was released on 1971-09 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Bulletin of the Atomic Scientists is the premier public resource on scientific and technological developments that impact global security. Founded by Manhattan Project Scientists, the Bulletin's iconic "Doomsday Clock" stimulates solutions for a safer world.
Download or read book Status of Fast Reactor Research and Technology Development written by International Atomic Energy Agency and published by . This book was released on 2012 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Based on a recommendation from the Technical Working Group on Fast Reactors, this publication is a regular update of previous publications on fast reactor technology. The publication provides comprehensive and detailed information on the technology of fast neutron reactors. The focus is on practical issues that are useful to engineers, scientists, managers, university students and professors. The main issues of discussion are experience in design, construction, operation and decommissioning, various areas of research and development, engineering, safety and national strategies, and public acceptance of fast reactors. In the summary the reader will find national strategies, international initiatives on innovative (i.e. Generation IV) systems and an assessment of public acceptance as related to fast reactors."--Résumé de l'éditeur.
Download or read book Report on INL Activities for Uncertainty Reduction Analysis of FY12 written by and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The work scope of this project related to the Work Packages of "Uncertainty Reduction Analyses" with the goal of reducing nuclear data uncertainties is to produce a set of improved nuclear data to be used both for a wide range of validated advanced fast reactor design calculations, and for providing guidelines for further improvements of the ENDF/B files (i.e. ENDF/B-VII, and future releases). Recent extensive sensitivity/uncertainty studies, performed within an international OECD-NEA initiative, have quantified for the first time the impact of current nuclear data uncertainties on design parameters of the major FCR & D and GEN-IV systems, and in particular on Na-cooled fast reactors with different fuels (oxide or metal), fuel composition (e.g. different Pu/TRU ratios) and different conversion ratios. These studies have pointed out that present uncertainties on the nuclear data should be significantly reduced, in order to get full benefit from the advanced modeling and simulation initiatives. Nuclear data plays a fundamental role in performance calculations of advanced reactor concepts. Uncertainties in the nuclear data propagate into uncertainties in calculated integral quantities, driving margins and costs in advanced system design, operation and safeguards. This package contributes to the resolution of technical, cost, safety, security and proliferation concerns in a multi-pronged, systematic, science-based R & D approach. The Nuclear Data effort identifies and develops small scale, phenomenon-specific experiments informed by theory and engineering to reduce the number of large, expensive integral experiments. The Nuclear Data activities are leveraged by effective collaborations between experiment and theory, between DOE programs and offices, at national laboratories and universities, both domestic and international. The primary objective is to develop reactor core sensitivity and uncertainty analyses that identify the improvement needs of key nuclear data which would facilitate fast spectrum system optimization and assure safety performance. The inclusion of fast spectrum integral experiment data is key to minimizing the impact of nuclear data uncertainties on reactor core performance calculations, thus providing the best nuclear data needs assessment. This report presents the status of activities performed at INL under the ARC Work Package previously mentioned. As major achievement this year a comprehensive adjustment, including 87 experiments, was carried out. The results of this adjustment provide useful insights and helpful feedback to both nuclear data evaluation and measurer communities. In the following, we will document first the theory that underlines the adjustment methodology, and then we will illustrate the sensitivity coefficient computation and the nuclear data and experiment selection. Subsequently, the adjustment results will be shown, and, finally, conclusions, including future work, will be provided.
Download or read book Bulletin of the Atomic Scientists written by and published by . This book was released on 1970-06 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Bulletin of the Atomic Scientists is the premier public resource on scientific and technological developments that impact global security. Founded by Manhattan Project Scientists, the Bulletin's iconic "Doomsday Clock" stimulates solutions for a safer world.
Download or read book Methodology for Uncertainty Analysis of Advanced Fuel Cycles and Preliminary Results written by and published by . This book was released on 2006 with total page 85 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report assesses the sensitivity and uncertainty associated with certain advanced nuclear fuel cycles due to the variance of chosen parameters and how these results relate to the deep geological nuclear waste repository. High burn up uranium oxide, mixed oxide, and fast spectrum nuclear fuels are the advanced fuel cycles considered. The parameters that are varied in these cases are: the time of advanced fuel implementation, energy growth rate, fuel burn up, and reprocessing introduction and capacity. The results analyzed are the amount of spent fuel and the amount of Pu in spent fuel in the year 2099. The advanced fuel cycle scenarios are modeled using the DANESS code developed by Argonne National Laboratory. All the fuel cycles modeled in this report are highly sensitive to the above-mentioned varied parameters. In a 0% energy growth rate case the plutonium fast burner reactor significantly reduces the amount of waste destined to the repository. Compared to current once-through fuel cycle practices, the fast reactor reduces waste by 50-52 percent. As energy demand grows, the high burn up case of 100 (GWd per ton heavy metal) fuel, as modeled in this thesis, reduces the mass destined for the repository greatest. In the 1.5% energy growth rate, spent fuel mass is reduced 32-44 percent, and in the 3.0% energy growth rate those numbers are 43-49 percent.
Download or read book Use of Forward Sensitivity Analysis Method to Improve Code Scaling Applicability and Uncertainty CSAU Methodology written by and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Code Scaling, Applicability, and Uncertainty (CSAU) methodology was developed in late 1980s by US NRC to systematically quantify reactor simulation uncertainty. Basing on CSAU methodology, Best Estimate Plus Uncertainty (BEPU) methods have been developed and widely used for new reactor designs and existing LWRs power uprate. In spite of these successes, several aspects of CSAU have been criticized for further improvement: i.e., (1) subjective judgement in PIRT process; (2) high cost due to heavily relying large experimental database, needing many experts man-years work, and very high computational overhead; (3) mixing numerical errors with other uncertainties; (4) grid dependence and same numerical grids for both scaled experiments and real plants applications; (5) user effects; Although large amount of efforts have been used to improve CSAU methodology, the above issues still exist. With the effort to develop next generation safety analysis codes, new opportunities appear to take advantage of new numerical methods, better physical models, and modern uncertainty qualification methods. Forward sensitivity analysis (FSA) directly solves the PDEs for parameter sensitivities (defined as the differential of physical solution with respective to any constant parameter). When the parameter sensitivities are available in a new advanced system analysis code, CSAU could be significantly improved: (1) Quantifying numerical errors: New codes which are totally implicit and with higher order accuracy can run much faster with numerical errors quantified by FSA. (2) Quantitative PIRT (Q-PIRT) to reduce subjective judgement and improving efficiency: treat numerical errors as special sensitivities against other physical uncertainties; only parameters having large uncertainty effects on design criterions are considered. (3) Greatly reducing computational costs for uncertainty qualification by (a) choosing optimized time steps and spatial sizes; (b) using gradient information (sensitivity result) to reduce sampling number. (4) Allowing grid independence for scaled integral effect test (IET) simulation and real plant applications: (a) eliminate numerical uncertainty on scaling; (b) reduce experimental cost by allowing smaller scaled IET; (c) eliminate user effects. This paper will review the issues related to the current CSAU, introduce FSA, discuss a potential Q-PIRT process, and show simple examples to perform FSA. Finally, the general research direction and requirements to use FSA in a system analysis code will be discussed.
Download or read book Bulletin of the Atomic Scientists written by and published by . This book was released on 1971-09 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Bulletin of the Atomic Scientists is the premier public resource on scientific and technological developments that impact global security. Founded by Manhattan Project Scientists, the Bulletin's iconic "Doomsday Clock" stimulates solutions for a safer world.
Download or read book Sodium Fast Reactors with Closed Fuel Cycle written by Baldev Raj and published by CRC Press. This book was released on 2015-04-15 with total page 901 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sodium Fast Reactors with Closed Fuel Cycle delivers a detailed discussion of an important technology that is being harnessed for commercial energy production in many parts of the world. Presenting the state of the art of sodium-cooled fast reactors with closed fuel cycles, this book:Offers in-depth coverage of reactor physics, materials, design, s
Download or read book Comparison of Uncertainty Quantification Methods for Fast Reactor Neutronics written by and published by . This book was released on 2010 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Future of Nuclear Fuel Cycle written by and published by . This book was released on 2011 with total page 237 pages. Available in PDF, EPUB and Kindle. Book excerpt: "In this analysis we have presented a method that provides insight into future fuel cycle alternatives by clarifying the complexity of choosing an appropriate fuel cycle in the context of the distribution of burdens and benefits between generations. The current nuclear power deployment practices, together with three future fuel cycles were assessed."--Page 227.
Download or read book BEMUSE Programme Best estimate Methods Uncertainty and Sensitivity Evaluation written by Nuclear Energy Agency. Committee on the Safety of Nuclear Installations and published by . This book was released on 2009 with total page 94 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Bulletin of the Atomic Scientists written by and published by . This book was released on 1980-01 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Bulletin of the Atomic Scientists is the premier public resource on scientific and technological developments that impact global security. Founded by Manhattan Project Scientists, the Bulletin's iconic "Doomsday Clock" stimulates solutions for a safer world.
