Sensitivity Analysis and Optimization of the Nuclear Fuel Cycle

Sensitivity Analysis and Optimization of the Nuclear Fuel Cycle PDF Author: Stefano Passerini
Publisher:
ISBN:
Category :
Languages : en
Pages : 309

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Book Description
For decades, nuclear energy development was based on the expectation that recycling of the fissionable materials in the used fuel from today's light water reactors into advanced (fast) reactors would be implemented as soon as technically feasible in order to extend the nuclear fuel resources. More recently, arguments have been made for deployment of fast reactors in order to reduce the amount of higher actinides, hence the longevity of radioactivity, in the materials destined to a geologic repository. The cost of the fast reactors, together with concerns about the proliferation of the technology of extraction of plutonium from used LWR fuel as well as the large investments in construction of reprocessing facilities have been the basis for arguments to defer the introduction of recycling technologies in many countries including the US. In this thesis, the impacts of alternative reactor technologies on the fuel cycle are assessed. Additionally, metrics to characterize the fuel cycles and systematic approaches to using them to optimize the fuel cycle are presented. The fuel cycle options of the 2010 MIT fuel cycle study are re-examined in light of the expected slower rate of growth in nuclear energy today, using the CAFCA (Code for Advanced Fuel Cycle Analysis). The Once Through Cycle (OTC) is considered as the base-line case, while advanced technologies with fuel recycling characterize the alternative fuel cycle options available in the future. The options include limited recycling in LWRs and full recycling in fast reactors and in high conversion LWRs. Fast reactor technologies studied include both oxide and metal fueled reactors. Additional fuel cycle scenarios presented for the first time in this work assume the deployment of innovative recycling reactor technologies such as the Reduced Moderation Boiling Water Reactors and Uranium-235 initiated Fast Reactors. A sensitivity study focused on system and technology parameters of interest has been conducted to test the robustness of the conclusions presented in the MIT Fuel Cycle Study. These conclusions are found to still hold, even when considering alternative technologies and different sets of simulation assumptions. Additionally, a first of a kind optimization scheme for the nuclear fuel cycle analysis is proposed and the applications of such an optimization are discussed. Optimization metrics of interest for different stakeholders in the fuel cycle (economics, fuel resource utilization, high level waste, transuranics/proliferation management, and environmental impact) are utilized for two different optimization techniques: a linear one and a stochastic one. Stakeholder elicitation provided sets of relative weights for the identified metrics appropriate to each stakeholder group, which were then successfully used to arrive at optimum fuel cycle configurations for recycling technologies. The stochastic optimization tool, based on a genetic algorithm, was used to identify non-inferior solutions according to Pareto's dominance approach to optimization. The main tradeoff for fuel cycle optimization was found to be between economics and most of the other identified metrics.

Sensitivity Analysis and Optimization of the Nuclear Fuel Cycle

Sensitivity Analysis and Optimization of the Nuclear Fuel Cycle PDF Author: Stefano Passerini
Publisher:
ISBN:
Category :
Languages : en
Pages : 309

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Book Description
For decades, nuclear energy development was based on the expectation that recycling of the fissionable materials in the used fuel from today's light water reactors into advanced (fast) reactors would be implemented as soon as technically feasible in order to extend the nuclear fuel resources. More recently, arguments have been made for deployment of fast reactors in order to reduce the amount of higher actinides, hence the longevity of radioactivity, in the materials destined to a geologic repository. The cost of the fast reactors, together with concerns about the proliferation of the technology of extraction of plutonium from used LWR fuel as well as the large investments in construction of reprocessing facilities have been the basis for arguments to defer the introduction of recycling technologies in many countries including the US. In this thesis, the impacts of alternative reactor technologies on the fuel cycle are assessed. Additionally, metrics to characterize the fuel cycles and systematic approaches to using them to optimize the fuel cycle are presented. The fuel cycle options of the 2010 MIT fuel cycle study are re-examined in light of the expected slower rate of growth in nuclear energy today, using the CAFCA (Code for Advanced Fuel Cycle Analysis). The Once Through Cycle (OTC) is considered as the base-line case, while advanced technologies with fuel recycling characterize the alternative fuel cycle options available in the future. The options include limited recycling in LWRs and full recycling in fast reactors and in high conversion LWRs. Fast reactor technologies studied include both oxide and metal fueled reactors. Additional fuel cycle scenarios presented for the first time in this work assume the deployment of innovative recycling reactor technologies such as the Reduced Moderation Boiling Water Reactors and Uranium-235 initiated Fast Reactors. A sensitivity study focused on system and technology parameters of interest has been conducted to test the robustness of the conclusions presented in the MIT Fuel Cycle Study. These conclusions are found to still hold, even when considering alternative technologies and different sets of simulation assumptions. Additionally, a first of a kind optimization scheme for the nuclear fuel cycle analysis is proposed and the applications of such an optimization are discussed. Optimization metrics of interest for different stakeholders in the fuel cycle (economics, fuel resource utilization, high level waste, transuranics/proliferation management, and environmental impact) are utilized for two different optimization techniques: a linear one and a stochastic one. Stakeholder elicitation provided sets of relative weights for the identified metrics appropriate to each stakeholder group, which were then successfully used to arrive at optimum fuel cycle configurations for recycling technologies. The stochastic optimization tool, based on a genetic algorithm, was used to identify non-inferior solutions according to Pareto's dominance approach to optimization. The main tradeoff for fuel cycle optimization was found to be between economics and most of the other identified metrics.

Nuclear Fuel Cycle Optimization

Nuclear Fuel Cycle Optimization PDF Author: P. Silvennoinen
Publisher: Elsevier
ISBN: 1483145549
Category : Technology & Engineering
Languages : en
Pages : 139

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Book Description
Nuclear Fuel Cycle Optimization: Methods and Modelling Techniques discusses applicable methods for analysis of fuel cycle logistics and optimization and evaluation of the economics of various reactor strategies. The opening chapter covers the nuclear fuel cycle, while the next chapter tackles uranium supply and demand. Chapter 3 discusses basic model of the light water reactor (LWR). The fourth chapter talks about the resolution of uncertainties, and the fifth chapter discusses the assessment of proliferation risks. Chapter 6 covers multigoal optimization, while Chapter 7 deals with the generalized fuel cycle models. The eighth chapter covers reactor strategy calculations, whereas the last chapter discusses interface with energy strategy. The book will appeal to students of energy economics or of nuclear engineering.

High Fidelity Nuclear Energy System Optimization Towards an Environmentally Benign, Sustainable, and Secure Energy Source

High Fidelity Nuclear Energy System Optimization Towards an Environmentally Benign, Sustainable, and Secure Energy Source PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 76

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Book Description
The impact associated with energy generation and utilization is immeasurable due to the immense, widespread, and myriad effects it has on the world and its inhabitants. The polar extremes are demonstrated on the one hand, by the high quality of life enjoyed by individuals with access to abundant reliable energy sources, and on the other hand by the global-scale environmental degradation attributed to the affects of energy production and use. Thus, nations strive to increase their energy generation, but are faced with the challenge of doing so with a minimal impact on the environment and in a manner that is self-reliant. Consequently, a revival of interest in nuclear energy has followed, with much focus placed on technologies for transmuting nuclear spent fuel. The performed research investigates nuclear energy systems that optimize the destruction of nuclear waste. In the context of this effort, nuclear energy system is defined as a configuration of nuclear reactors and corresponding fuel cycle components. The proposed system has unique characteristics that set it apart from other systems. Most notably the dedicated High-Energy External Source Transmuter (HEST), which is envisioned as an advanced incinerator used in combination with thermal reactors. The system is configured for examining environmentally benign fuel cycle options by focusing on minimization or elimination of high level waste inventories. Detailed high-fidelity exact-geometry models were developed for representative reactor configurations. They were used in preliminary calculations with Monte Carlo N-Particle eXtented (MCNPX) and Standardized Computer Analysis for Licensing Evaluation (SCALE) code systems. The reactor models have been benchmarked against existing experimental data and design data. Simulink{reg_sign}, an extension of MATLAB{reg_sign}, is envisioned as the interface environment for constructing the nuclear energy system model by linking the individual reactor and fuel component sub-models for overall analysis of the system. It also provides control over key user input parameters and the ability to effectively consolidate vital output results for uncertainty/sensitivity analysis and optimization procedures. The preliminary analysis has shown promising advanced fuel cycle scenarios that include Pressure Water Reactors Pressurized Water Reactors (PWRs), Very High Temperature Reactors (VHTRs) and dedicated HEST waste incineration facilities. If deployed, these scenarios may substantially reduce nuclear waste inventories approaching environmentally benign nuclear energy system characteristics. Additionally, a spent fuel database of the isotopic compositions for multiple design and control parameters has been created for the VHTR-HEST input fuel streams. Computational approaches, analysis metrics, and benchmark strategies have been established for future detailed studies.

High-fidelity Nuclear Energy System Optimization Towards an Environmentally Benign, Sustainable, and Secure Energy Source

High-fidelity Nuclear Energy System Optimization Towards an Environmentally Benign, Sustainable, and Secure Energy Source PDF Author: David Elroy Ames
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
A new high-fidelity integrated system method and analysis approach was developed and implemented for consistent and comprehensive evaluations of advanced fuel cycles leading to minimized Transuranic (TRU) inventories. The method has been implemented in a developed code system integrating capabilities of MCNPX for highfidelity fuel cycle component simulations. The impact associated with energy generation and utilization is immeasurable due to the immense, widespread, and myriad effects it has on the world and its inhabitants. The polar extremes are demonstrated on the one hand, by the high quality of life enjoyed by individuals with access to abundant reliable energy sources, and on the other hand by the global-scale environmental degradation attributed to the affects of energy production and use. Thus, nations strive to increase their energy generation, but are faced with the challenge of doing so with a minimal impact on the environment and in a manner that is self-reliant. Consequently, a revival of interest in nuclear energy has followed with much focus placed on technologies for transmuting nuclear spent fuel. In this dissertation, a Nuclear Energy System (NES) configuration was developed to take advantage of used fuel recycling and transmutation capabilities in waste management scenarios leading to minimized TRU waste inventories, long-term activities, and radiotoxicities. The reactor systems and fuel cycle components that make up the NES were selected for their ability to perform in tandem to produce clean, safe, and dependable energy in an environmentally conscious manner. The reactor systems include the AP1000, VHTR, and HEST. The diversity in performance and spectral characteristics for each was used to enhance TRU waste elimination while efficiently utilizing uranium resources and providing an abundant energy source. The High Level Waste (HLW) stream produced by typical nuclear systems was characterized according to the radionuclides that are key contributors to long-term waste management issues. The TRU component of the waste stream becomes the main radiological concern for time periods greater than 300 years. A TRU isotopic assessment was developed and implemented to produce a priority ranking system for the TRU nuclides as related to long-term waste management and their expected characteristics under irradiation in the different reactor systems of the NES. Detailed 3D whole-core models were developed for analysis of the individual reactor systems of the NES. As an inherent part of the process, the models were validated and verified by performing experiment-to-code and/or code-to-code benchmarking procedures, which provided substantiation for obtained data and results. Reactor core physics and material depletion calculations were performed and analyzed. A computational modeling approach was developed for integrating the individual models of the NES. A general approach was utilized allowing for the Integrated System Model (ISM) to be modified in order to provide simulation for other systems with similar attributes. By utilizing this approach, the ISM is capable of performing system evaluations under many different design parameter options. Additionally, the predictive capabilities of the ISM and its computational time efficiency allow for system sensitivity/uncertainty analysis and the implementation of optimization techniques. The NES has demonstrated great potential for providing safe, clean, and secure energy and doing so with foreseen advantages over the LEU once-through fuel cycle option. The main advantages exist due to better utilization of natural resources by recycling the used nuclear fuel, and by reducing the final amount and time span for which the resulting HLW must be isolated from the public and the environment due to radiological hazard. If deployed, the NES can substantially reduce the long-term radiological hazard posed by current HLW, extend uranium resources, and approach the characteristics of an environmentally benign energy system.

Development and Utilization of Mathematical Optimization in Advanced Fuel Cycle Systems Analysis

Development and Utilization of Mathematical Optimization in Advanced Fuel Cycle Systems Analysis PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
Over the past sixty years, a wide variety of nuclear power technologies have been theorized, investigated and tested to various degrees. These technologies, if properly applied, could provide a stable, long-term, economical source of CO2-free electric power. However, the recycling of nuclear fuel introduces a degree of coupling between reactor systems which must be accounted for when making long term strategic plans. This work investigates the use of a simulated annealing optimization algorithm coupled together with the VISION fuel cycle simulation model in order to identify attractive strategies from economic, evironmental, non-proliferation and waste-disposal perspectives, which each have associated an objective function. The simulated annealing optimization algorithm works by perturbing the fraction of new reactor capacity allocated to each available reactor type (using a set of heuristic rules) then evaluating the resulting deployment scenario outcomes using the VISION model and the chosen objective functions. These new scenarios, which are either accepted or rejected according the the Metropolis Criterion, are then used as the basis for further perturbations. By repeating this process several thousand times, a family of near-optimal solutions are obtained. Preliminary results from this work using a two-step, Once-through LWR to Full-recycle/FRburner deployment scenario with exponentially increasing electric demand indicate that the algorithm is capable of nding reactor deployment pro les that reduce the long-term-heat waste disposal burden relative to an initial reference scenario. Further work is under way to re ne the current results and to extend them to include the other objective functions and to examine the optimization trade-o s that exist between these di erent objectives.

יפה שעה

יפה שעה PDF Author: מכלוף ובחצרה
Publisher:
ISBN:
Category : Jewish law
Languages : en
Pages : 336

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Book Description


Advanced Nuclear Fuel Cycle Transitions

Advanced Nuclear Fuel Cycle Transitions PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 248

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Book Description
Many nuclear fuel cycle simulators have evolved over time to help understan the nuclear industry/ecosystem at a macroscopic level. Cyclus is one of th first fuel cycle simulators to accommodate larger-scale analysis with it liberal open-source licensing and first-class Linux support. Cyclus also ha features that uniquely enable investigating the effects of modeling choices o fuel cycle simulators and scenarios. This work is divided into thre experiments focusing on optimization, effects of modeling choices, and fue cycle uncertainty Effective optimization techniques are developed for automatically determinin desirable facility deployment schedules with Cyclus. A novel method fo mapping optimization variables to deployment schedules is developed. Thi allows relationships between reactor types and scenario constraints to b represented implicitly in the variable definitions enabling the usage o optimizers lacking constraint support. It also prevents wasting computationa resources evaluating infeasible deployment schedules. Deployed power capacit over time and deployment of non-reactor facilities are also included a optimization variables There are many fuel cycle simulators built with different combinations o modeling choices. Comparing results between them is often difficult. Cyclus flexibility allows comparing effects of many such modeling choices. Reacto refueling cycle synchronization and inter-facility competition among othe effects are compared in four cases each using combinations of fleet o individually modeled reactors with 1-month or 3-month time steps. There ar noticeable differences in results for the different cases. The larges differences occur during periods of constrained reactor fuel availability This and similar work can help improve the quality of fuel cycle analysi generally There is significant uncertainty associated deploying new nuclear technologie such as time-frames for technology availability and the cost of buildin advanced reactors. Historically, fuel cycle analysis has focused on answerin questions of fuel cycle feasibility and optimality. However, there has no been much work done to address uncertainty in fuel cycle analysis helpin answer questions of fuel cycle robustness. This work develops an demonstrates a methodology for evaluating deployment strategies whil accounting for uncertainty. Techniques are developed for measuring th hedging properties of deployment strategies under uncertainty. Additionally methods for using optimization to automatically find good hedging strategie are demonstrated

Application of Data-driven Methods in Nuclear Fuel Performance Analysis

Application of Data-driven Methods in Nuclear Fuel Performance Analysis PDF Author: Yifeng Che
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Book Description
Accurately predicting the behavior of nuclear fuel performance is essential for the safe and economic operation of nuclear reactors. Computer codes of different fidelities have been developed over past decades to simulate the behavior of nuclear fuels, such as the multi-dimensional, parallel, finite element-based code BISON, and the NRC-auditing code FRAPCON. Multiple areas of research remain to be addressed in fuel performance while physics-based approaches often reach their limits. Studies to be presented in this thesis therefore revolve around applying data-driven methods to address these issues. First, discrepancies always exist between code predictions and real-world responses, thus uncertainties must be quantified for the code predictions for benefit of decision making, operation safety and design optimization. Systematic validation and verification are performed for BISON first, followed by a holistic sensitivity analysis (SA) framework built upon a complete set of uncertain input parameters. The number of uncertain input parameters can be effectively reduced based on the obtained qualitative importance ranking, benefiting the subsequent uncertainty quantification (UQ). To enhance the predictability, a novel Bayesian inference framework is introduced to efficiently calibrate the expensive high fidelity tools, possibly without resorting to approximate surrogate methods. The calibrated prediction aligns better with experimental observations, and is subject to significantly reduced uncertainty. Second, while full-core monitoring of fuel behaviors can provide the most realistic assessment of safety margins, its computational cost for use in design and operation optimization is prohibitive. Machine learning (ML) methods were used to construct fast-running full-core surrogates, which achieves a runtime acceleration of more than 10,000 (1,000) times compared to FRAPCON for the standard (high burnup) PWR cores, allowing for direct coupling of full-core fuel response into core design optimization in the future. Then for purpose of full-core PCI monitoring which requires BISON as the high-fidelity simulation tool, a physics-informed multi-fidelity ML framework is introduced to significantly reduce the number of necessary code runs. Finally, deep learning models are trained to predict the spatiotemporal distribution of the cladding hoop stress. The proposed data-driven methods for the selected applications enlightens the nuclear community on practical pathways to realize meaningful improvements in fuel performance assessment.

Use of the SR-52 Hand Programmable Calculator to Perform a Nuclear Fuel Cycle Cost Sensitivity Analysis

Use of the SR-52 Hand Programmable Calculator to Perform a Nuclear Fuel Cycle Cost Sensitivity Analysis PDF Author: Orvis Wesley Taylor
Publisher:
ISBN:
Category : Nuclear fuels
Languages : en
Pages : 206

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The Nuclear Fuel Cycle

The Nuclear Fuel Cycle PDF Author: Robert G. Cochran
Publisher:
ISBN:
Category : Nuclear fuels
Languages : en
Pages : 406

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Book Description