Assessment of the Effect of Different Isolation Systems on Seismic Response of a Nuclear Power Plant

Assessment of the Effect of Different Isolation Systems on Seismic Response of a Nuclear Power Plant PDF Author: Jenna Wong
Publisher:
ISBN:
Category :
Languages : en
Pages : 200

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Book Description
Seismic isolation is utilized in both traditional and industrial structures for its ability to reduce structural responses while effectively protecting sensitive building contents. Although this mature technology has been studied extensively, there is limited research on its application to Nuclear Power Plants (NPPs). Studies have yet to address topics such as sensitivity of equipment and the effects of seismic isolation on floor response spectra (FRS) caused by high frequencies and the inclusion of vertical motion. This paper's studies investigate the relationship between structural response and isolator mechanics, ground motion sensitivity, and the effectiveness of various isolator types, especially nonlinear isolators. Overall trends are identified that provide insight into the interaction between the isolation system and the response at various levels of the NPP. By understanding these relationships and connections, a set of valid recommendations for the selection and design of isolation systems is provided. This work is pursued through analyzing the performance of an APR1400 plant considering regulatory guidelines and utilizing a variety of ground motions, isolator types, and isolator models.

Assessment of the Effect of Different Isolation Systems on Seismic Response of a Nuclear Power Plant

Assessment of the Effect of Different Isolation Systems on Seismic Response of a Nuclear Power Plant PDF Author: Jenna Wong
Publisher:
ISBN:
Category :
Languages : en
Pages : 200

Get Book Here

Book Description
Seismic isolation is utilized in both traditional and industrial structures for its ability to reduce structural responses while effectively protecting sensitive building contents. Although this mature technology has been studied extensively, there is limited research on its application to Nuclear Power Plants (NPPs). Studies have yet to address topics such as sensitivity of equipment and the effects of seismic isolation on floor response spectra (FRS) caused by high frequencies and the inclusion of vertical motion. This paper's studies investigate the relationship between structural response and isolator mechanics, ground motion sensitivity, and the effectiveness of various isolator types, especially nonlinear isolators. Overall trends are identified that provide insight into the interaction between the isolation system and the response at various levels of the NPP. By understanding these relationships and connections, a set of valid recommendations for the selection and design of isolation systems is provided. This work is pursued through analyzing the performance of an APR1400 plant considering regulatory guidelines and utilizing a variety of ground motions, isolator types, and isolator models.

Advanced Modeling and Evaluation of the Response of Base-Isolated Nuclear Facility Structures to Vertical Earthquake Excitation

Advanced Modeling and Evaluation of the Response of Base-Isolated Nuclear Facility Structures to Vertical Earthquake Excitation PDF Author: Eric Scott Keldrauk
Publisher:
ISBN:
Category :
Languages : en
Pages : 742

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Book Description
The commissioning and construction of new nuclear power plants in the United States has dwindled over the past 30 years despite significant innovation in reactor technology. This is partially due to the ever-increasing seismic hazard estimates, which increases the demand on and risk to nuclear power plant structures. Seismic base isolation is a mature technology which introduces a laterally-flexible and vertically-stiff layer between the foundation and superstructure to significantly reduce the seismic response of the structure, systems, and components therein. Such devices have also been noted to concentrate the displacement response in one plane, reduce higher-mode participation, and provide damping to protect against excessive displacements, all of which aid in increasing safety margins for seismically-isolated nuclear structures. Despite numerous studies analyzing the applicability of seismic base isolation to nuclear power plant structures, some of which are discussed herein, no seismically-isolated nuclear plant has been constructed in the United States. This study presents a time-domain procedure for analyzing the performance of seismically-isolated nuclear structures in response to design-basis earthquake events using ALE3D. The simulations serve as a parametric study to assess the effects of soil column type, seismic isolation model, superstructure mesh, and ground motion selection on global displacements, rotations, and accelerations, as well as internal floor accelerations. Explicit modeling of the soil columns and superstructures enables detailed analysis of soil-structure interaction. The soil columns analyzed have constant properties over the height of the finite element soil mesh and include rock, soft rock, and stiff soil sites, as well as a "no soil" case for comparison. Four separate 3-dimensional seismic isolation bearing models were coded into ALE3D and validated. These include models for friction pendulum, triple friction pendulum, simplified lead rubber, and robust lead rubber bearings. Lastly, two superstructure finite element meshes were considered: a cylindrical plant design meant to represent a typical conceptual design for advanced reactors, and a rectangular plant design meant to represent an advanced boiling water reactor. The ground motions considered include 30 three-component time history records scaled to meet the seismic hazard for the Diablo Canyon nuclear plant. Every combination of soil column, isolator model, and superstructure were subjected to a subset of three of the harshest ground motions, termed the "basic motions", and the combinations which included the rectangular plant design atop the rock soil column were subjected to all 30 motions. The results of the various simulations including accelerations in the soil columns and superstructures as well as displacements and rotations in the isolators and superstructures are presented. The results suggest three possible effects: an isolator-type effect, a soil-type effect, and a slenderness effect. The isolator-type effect refers to significant increases in vertical soil acceleration amplifications, isolator uplift/tension, and global rotations including torsion and overturning for friction bearings in comparison to elastomeric bearings. Additionally it is noted that inclusion of lead plug softening has the effect of increasing peak lateral isolator deformations, especially for the ground motions that naturally induce high-amplitude deformations in the bearings. These results suggest that uplift/tension may be troublesome in high-seismic areas and the use of restrainers should be analyzed as a possible solution. Furthermore, these results reinforce the lateral design displacement estimate procedures for seismically-isolated nuclear structures in ASCE4-11. The results prove that explicit inclusion of the soil column is necessary for proper response characterization and the chosen soil properties greatly affect the efficacy of seismic isolation designs. The soil-type effect comes from observations of comparative simulations which show that, in general, peak isolator uplift/tension and deformation, as well as peak global displacements and rotations including torsion and overturning increase as the soil column becomes less-stiff, regardless of the isolator model or superstructure considered. These results suggest that although seismic isolation can be effective for structures atop a variety of soil columns, it is imperative that a single isolator design only be considered applicable to a corresponding soil column unless extensive analyses prove otherwise for a specific case. Differences in peak response parameters between the two superstructures point to a possible slenderness effect. Specifically, the isolator deformations as well as the global displacements and rotations are observed to increase for the cylindrical superstructure in comparison to the rectangular superstructure cases utilizing the same ground motion, soil column, and isolator model. Should further research reaffirm this effect, a practical limit could be set for superstructure slenderness.

Hybrid Simulation to Assess Performance of Seismic Isolation in Nuclear Power Plants

Hybrid Simulation to Assess Performance of Seismic Isolation in Nuclear Power Plants PDF Author: International Atomic Energy Agency
Publisher:
ISBN: 9789201627193
Category : Technology & Engineering
Languages : en
Pages : 0

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Book Description
Seismic isolation technology has the potential to significantly reduce the overall risk posed by earthquake ground motions to nuclear power plants. A testing programme is an integral part of a seismic isolation project. Not only must the isolating devices be characterized for design purposes, but also validation of the analytical procedures used in design is required. Hybrid simulation is a testing technique which is a good candidate to experimentally assess the behaviour of an isolation system. The method combines the computation of the response of the isolated structure with the experimental determination of the behaviour of full-scale isolators under the demand imposed by the movement of ground and structure. This publication contributes to the assessment of the method as a tool for the design and safety demonstration of base-isolated nuclear facility buildings.

Seismic Design and Qualification for Nuclear Power Plants

Seismic Design and Qualification for Nuclear Power Plants PDF Author:
Publisher:
ISBN:
Category : Business & Economics
Languages : en
Pages : 96

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Book Description
This guide was originally issued as Safety Guide No. 50-SG-S2. It provides details on the design of a nuclear power plant such that earthquakes at the site determined according to Safety Guide No. 50-SG-S1 will not jeopardize its safety.

Infrastructure Systems for Nuclear Energy

Infrastructure Systems for Nuclear Energy PDF Author: Thomas T. C. Hsu
Publisher: John Wiley & Sons
ISBN: 1118536266
Category : Technology & Engineering
Languages : en
Pages : 563

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Book Description
Developing sufficient energy resources to replace coal, oil and gas is a globally critical necessity. Alternatives to fossil fuels such as wind, solar, or geothermal energies are desirable, but the usable quantities are limited and each has inherent deterrents. The only virtually unlimited energy source is nuclear energy, where safety of infrastructure systems is the paramount concern. Infrastructure Systems for Nuclear Energy addresses the analysis and design of infrastructures associated with nuclear energy. It provides an overview of the current and future nuclear power industry and the infrastructure systems from the perspectives of regulators, operators, practicing engineers and research academics. This book also provides details on investigations of containment structures, nuclear waste storage facilities and the applications of commercial/academic computer software. Specific environments that challenge the behavior of nuclear power plants infrastructure systems such as earthquake, blast, high temperature, irradiation effects, soil-structure interaction effect, etc., are also discussed. Key features: Includes contributions from global experts representing academia and industry Provides an overview of the nuclear power industry and nuclear infrastructure systems Presents the state-of-the-art as well as the future direction for nuclear civil infrastructure systems Infrastructure Systems for Nuclear Energy is a comprehensive, up-to-date reference for researchers and practitioners working in this field and for graduate studies in civil and mechanical engineering.

Seismic Analysis and Testing of Nuclear Power Plants

Seismic Analysis and Testing of Nuclear Power Plants PDF Author: International Atomic Energy Agency
Publisher:
ISBN:
Category : Business & Economics
Languages : en
Pages : 80

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Seismic Isolation and Response Control

Seismic Isolation and Response Control PDF Author: Eftychia Apostolidi
Publisher: International Association for Bridge and Structural Engineering
ISBN: 385748182X
Category : Technology & Engineering
Languages : de
Pages : 111

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Book Description
The seismic resilience of new and existing structures is a key priority for the protection of human lives and the reduction of economic losses in earthquake prone areas. The modern seismic codes have focused on the upgrade of the structural performance of the new and existing structures. However, in many cases it is preferrable to mitigate the effects of the earthquakes by reducing the induced loads in the structures using seismic isolation and response control devices. The limited expertise in the selection and design of the appropriate system for new and existing structures is the main challenge for an extensive use of seismic isolation and response control systems in practice. This document aims to provide a practical guide by presenting a collection of the most commonly used seismic isolation and response control systems and a critical evaluation of the main characteristics of these systems. Comparisons of the key parameters of the design processes for new buildings with seismic isolation are presented, while the application of seismic isolation systems and response control systems for the retrofitting of existing structures is also examined, followed by various case studies from Greece, Japan, Mexico, New Zealand, and Turkey.

Seismic Response Analysis of Nuclear Power Plant Systems

Seismic Response Analysis of Nuclear Power Plant Systems PDF Author: Asadour H. Hadjian
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Energy Research Abstracts

Energy Research Abstracts PDF Author:
Publisher:
ISBN:
Category : Power resources
Languages : en
Pages : 782

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Federal Register

Federal Register PDF Author:
Publisher:
ISBN:
Category : Administrative law
Languages : en
Pages : 1528

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Book Description