Author: Ildo Luís SauerPublisher:
ISBN:
Category :
Languages : en
Pages : 283
Book Description
Acore Reload Pattern and Composition Optimization Methodology for Pressurized Water Reactors
Author: Ildo Luís SauerA Core Reload Pattern and Composition Optimization Methodology for Pressurized Water Reactors
Author: Ildo Luis SauerPublisher:
ISBN:
Category : Pressurized water reactors
Languages : en
Pages : 283
Book Description
The primary objective of this research was the development of a comprehensive, rapid and conceptually simple methodology for PWR core reload pattern and fuel composition optimization, capable of systematic incorporation of constraints, in which cycle burnup is defined as the optimality criterion. A coarse mesh nodal method for PWR core analysis was formulated by coupling the one-and-one-half-group diffusion theory model for spatial power calculations with the linear reactivity versus burnup model (LRM) for depletion calculations. The accuracy and suitability of this model was determined through comparisons of its results with those of state-of-the-art core analysis methods. The simplicity of the LRM-based core model allowed the direct analytical computation of the derivatives necessary in the steepest gradient type optimization methods applied in the present work, and its versatility permitted use of the analytical and computational methods for a variety of applications, ranging from core reload pattern searches to burnable poison (BP) and composition optimization. Algorithms for identification of unconstrained maximum-burnup core reload patterns and for optimal BP allocation were successfully implemented and tested, and the basis for systematic incorporation of constraints on power peaking was developed. The potential application of the methodology to fuel composition optimization was also examined. Most of the methodological developments have been embodied in the LRM-NODAL code which was programmed in the course of this research. From the numerical and analytical results it was found that the optimal core configurations are arranged such as to produce power histories and profiles in which the most reactive assemblies are at their highest allowable power at EOC (thus maximizing their importance) and where the converse applies to the least reactive; these preferred profiles also produce relatively higher leakage at EOC, evolving to the lowest possible leakage at EOC, but always consistent with the maximization of the core reactivity importance.
A Core Reload Pattern and Composition Optimzation Methodology for Pressurized Water Reactors
Author: Ildo Luis SauerA Hybrid Method for In-core Optimization of Pressurized Water Reactor Reload Core Design
Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 209
Book Description
The objective of this research is the development of an accurate, practical, and robust method for optimization of the design of loading patterns for pressurized water reactors, a nonlinear, non-convex, integer optimization problem. The many logical constraints which may be applied during the design process are modeled herein by a network construction upon which performance objectives and safety constraints from reactor physics calculations are optimized. This thesis presents the synthesis of the strengths of previous algorithms developed for reload design optimization and extension of robustness through development of a hybrid liberated search algorithm. Development of three independent methods for reload design optimization is presented: random direct search for local improvement, liberated search by simulated annealing, and deterministic search for local improvement via successive linear assignment by branch and bound. Comparative application of the methods to a variety of problems is discussed, including an exhaustive enumeration benchmark created to allow comparison of search results to a known global optimum for a large scale problem. While direct search and determinism are shown to be capable of finding improvement, only the liberation of simulated annealing is found to perform robustly in the non-convex design spaces. The hybrid method SHAMAN is presented. The algorithm applies: determinism to shuffle an initial solution for satisfaction of heuristics and symmetry; liberated search through simulated annealing with a bounds cooling constraint treatment; and search bias through relational heuristics for the application of engineering judgment. The accuracy, practicality, and robustness of the SHAMAN algorithm is demonstrated through application to a variety of reload loading pattern optimization problems.
Application of Mathematical Optimization Techniques to Nuclear Reactor Reload Pattern Design
Author: Adriaan Jacobus QuistPublisher:
ISBN: 9789090137704
Category :
Languages : en
Pages : 211
Book Description
In-core Optimization of Pressurised Water Reactor Reload Design Via Multi-objective Tabu Search
Author: Joseph MawdsleyOptimization Algorithms in Boiling Water Reactor Lattice Design
Author: Chad D. Burns (III.)Publisher:
ISBN:
Category :
Languages : en
Pages : 40
Book Description
Given the highly complex nature of neutronics and reactor physics, efficient methods of optimizing are necessary to effectively design the core reloading pattern and operate a nuclear reactor. The current popular methods for optimization are Simulated Annealing and the Genetic Algorithm; this paper explores the potential for a new method called Greedy Exhaustive Dual Binary Swaps (GEDBS). The mandatory trade-off in computation is accuracy for speed; GEDBS is an exhaustive search and tends toward longer runtimes. While GEDBS performed acceptably for the criterion administered in this paper (local peaking and k, on a Boiling Water Reactor (BWR) fuel lattice) the exhaustive nature of GEDBS will inevitably lead to combinatorial explosion for the addition of the potential dozens of factors that commercial application mandates. This issue may be resolved with the addition of metaheuristics to reduce the search space for GEDBS, or by an increasing computation.
Composition Optimization of Thorium-uranium Pressurized Water Reactor Cores
Author: Kevin Taylor ClarnoOptimization of Nuclear Reactor Reloading Patterns
Author: E. de KlerkOptimization of In-core Nuclear Fuel Management in a Pressurized Water Reactor
Author: Richard Bartholomew StoutPublisher:
ISBN:
Category : Nuclear fuels
Languages : en
Pages : 316
Book Description
Fuel loading patterns which have a minimum power peak are economically desirable to allow power reactors to operate at the highest possible power density and to minimize the possibility of fuel failure. A computer code called SHUFLE was developed for pressurized water reactors which shuffles the fuel in search of the lowest possible power peaking factor. An iterative approach is used in this search routine. A radial power distribution is calculated from which the program logic Selects a movement of fuel elements in an attempt to lower the radial power peak. Another power calculation is made and the process repeated until a predetermined convergence is reached. The logic by which the code decides the fuel movement is presented, along with the criteria for accepting or rejecting the move after a power calculation of the new loading pattern is made. A 1.5 group course mesh diffusion theory method was used to obtain the power distribution for each SHUFLE iteration. Convergence to a final loading pattern varies from about 10 to 40 shuffling iterations depending on the initial loading presented to the code. Since the typical computer running time for a one-quarter core power distribution with this 1.5 group method is only one to a few seconds, depending on the loading, convergence to a good loading pattern takes on the order of one minute on a Univac 1108. The low computer cost plus ease of operation should make this code of considerable use in determining loading patterns with minimum power peaking for any given set of fuel elements. The program also has burnup capability which can be used to check power peaking throughout core life. A parametric analysis study of fuel cycle costs for a PWR is also presented. Cost parameters analyzed were variation in the cost of yellow cake, enrichment, money, fabrication, and reprocessing plus changes in burnup, load factors, power densities, and the effect of forced early discharge. Figures are presented to indicate total fuel costs as a function of burnup for these cost parameters. Linear relationships for minimum cost and optimum burnup are presented for each parameter.