Seismic Risk Analysis Of Nuclear Power Plants

A systematic and comprehensive introduction of seismic risk analysis of critical engineering structures, focusing on nuclear power plants.

This book is devoted to diverse aspects of earthquake researches, especially to new achievements in seismicity that involves geosciences, assessment, and mitigation. Chapters contain advanced materials of detailed engineering investigations, which can help more clearly appreciate, predict, and manage different earthquake processes. Different research themes for diverse areas in the world are developed here, highlighting new methods of studies that lead to new results and models, which could be helpful for the earthquake risk. The presented and developed themes mainly concern wave's characterization and decomposition, recent seismic activity, assessment-mitigation, and engineering techniques. The book provides the state of the art on recent progress in earthquake engineering and management. The obtained results show a scientific progress that has an international scope and, consequently, should open perspectives to other still unresolved interesting aspects.

This book collects the papers presented at the 7th International Conference on Risk Analysis and Crisis Response (RACR-2019) held in Athens, Greece, on October 15-19, 2019. The overall theme of the seventh international conference on risk analysis and crisis response is Risk Analysis Based on Data and Crisis Response Beyond Knowledge, highlighting science and technology to improve risk analysis capabilities and to optimize crisis response strategy. This book contains primarily research articles of risk issues. Underlying topics include natural hazards and major (chemical) accidents prevention, disaster risk reduction and society resilience, information and communication technologies safety and cybersecurity, modern trends in crisis management, energy and resources security, critical infrastructure, nanotechnology safety and others. All topics include aspects of multidisciplinarity and complexity of safety in education and research. The book should be valuable to professors, engineers, officials, businessmen and graduate students in risk analysis and risk management.

The development of protective measures to guard against the spread of radioactive debris following reactor disasters has been given extensive and careful engineering attention over the past several years. Much of this attention has been devoted to eliminating or minimizing the effects of malfunctions of internal components. But reactors can also suffer externally caused disasters—for example, their radioactive cores can be damaged by earthquakes or by missiles generated by tornadoes. Earthquakes in particular will continue to render man vulnerable even to the "peaceful atom" as the number of nuclear power plants increases and as they come to be located in those parts of the world that have a history of seismic activity. It was to consider such problems that the seminar reported here was held. The conferees, who are leaders in this special and important field, gathered in Cambridge, Massachusetts, in spring 1969, to present the papers whose titles are listed below. Together they cover both the theoretical underpinnings of the subject and specific applications to nuclear reactors; they provide both useful summaries of what is known to date and some new thinking on the subject, not before published. Contents: Preface—T. J. Thompson. Foreword—R. J. Hansen. Introduction—R. V. Whitman. Geological and Seismological Factors Influencing the Assessment of a Seismic Threat to Nuclear Reactors—Daniel Linehan, S. J. Geophysics—Keiiti Aki. Design Seismic Inputs—C. Allin Cornell. Some Observations on Probabilistic Methods in the Seismic Design of Nuclear Power Plants—C. Allin Cornell. Seismic Risk and Seismic Design Decisions—Luis Esteva. Fundamentals of Soil Amplification—J. M. Roesset. Soil Structure Interaction—R. V. Whitman. Evaluation of Soil Properties for Site Evaluation and Dynamic Analysis of Nuclear Plants—R. V. Whitman. Structural Response to Seismic Input—J. M. Biggs. Seismic Analysis of Equipment Mounted on a Massive Structure—J. M. Biggs and J. M. Roesset. Modal Response of Containment Structures—Peter Jan Pahl. Provision of Required Seismic Resistance—M. J. Holley, Jr. A Measure of Earthquake Intensity—Arturo Arias. Closure—R. J. Hansen.

Experience shows that an assessment of the seismic capacity of an existing operating facility can be required for a number of reasons, for example identification of potential seismic vulnerabilities based on operating experience events or the periodic safety review programme. This publication covers the seismic safety evaluation programmes to be performed on existing nuclear installations in order to ensure that the required fundamental safety functions are available, with particular application to the safe shutdown of reactors. It includes lessons learned based on the IAEA Action Plan for Strengthening Nuclear Safety, following the Fukushima accident, and updated methodologies for seismic safety evaluation of nuclear installations.

The state-of-the-art in seismic risk analysis applied to the design and siting of nuclear power plants was addressed in this meeting. Presentations were entered individually into the date base. (ACR).

This paper describes seismic risk, load combination, and probabilistic risk problems in power plant reliability, and it suggests applications of extreme value theory. Seismic risk analysis computes the probability of power plant failure in an earthquake and the resulting risk. Components fail if their peak responses to an earthquake exceed their strengths. Dependent stochastic processes represent responses, and peak responses are maxima. A Boolean function of component failures and survivals represents plant failure. Load combinations analysis computes the cdf of the peak of the superposition of stochastic processes that represent earthquake and operating loads. It also computes the probability of pipe fracture due to crack growth, a Markov process, caused by loads. Pipe fracture is an absorbing state. Probabilistic risk analysis computes the cdf's of probabilities which represent uncertainty. These Cdf's are induced by randomizing parameters of cdf's and by randomizing properties of stochastic processes such as initial crack size distributions, marginal cdf's, and failure criteria.

Earthquakes are destructive natural disasters that can inflict various levels of damage on engineering structures and lead to other adverse consequences. Accurate seismic risk quantification of critical engineering structures such as nuclear power plants is of great importance, not only for answering public safety concern but also for facilitating risk-informed decision making. Seismic Probabilistic Risk Analysis (SPRA) has been widely used for seismic analysis and design of critical engineering structures. It combines the probabilistic model of the behavior of structural response given a ground-motion parameter (GMP) value (e.g., seismic fragility model) and the Probabilistic Seismic Hazard Analysis (PSHA) for the GMP in a mathematically rigorous manner. However, there are a number of issues on the engineering application of SPRA that need to be addressed before it can be readily implemented into current engineering practice. In current SPRA practice, both the fragility model and PSHA are based on a single GMP, which is adequate for the single-mode-dominant structures. For multiple-mode-dominant structures, whose response could be better predicted using multiple GMP,a vector-valued SPRA is conceptually more appropriate. However, vector-valued SPRA requires extensive computational efforts and extensive consultation of vector-valued PSHA from seismologists,which prevent it from being ready for engineering purposes. The objective of this study is to bridge the gaps between seismological analyses and engineering applications, i.e., to address the immediate issues in current vector-valued SPRA so that it can be readily applied into engineering practice. A new seismic hazard deaggregation procedure is developed for seismic risk analysis, which determines a set of controlling earthquakes that induce dominant hazard to the site of interest. A simplified approach to vector-valued SPRA is developed based on the controlling earthquakes. Integration over all possible earthquake occurrences in standard vector-valued SPRA is then avoided,which substantially improves the computational efficiency without losing accuracy. This overcomes the deficiencies and preserves the advantages of standard vector-valued SPRA. To facilitate performing the simplified approach, factors affecting the accuracy of the simplified approach are discussed and illustrated through the numerical examples. In addition, seismic capacity evaluation of nuclear facilities is an important task in a SPRA. However, following the current evaluation procedures, inconsistency in seismic capacity estimates are often obtained for the same facility in similar plants at different locations. The inconsistency also shows dependency on the GMP selected for defining seismic capacity. This inconsistency is conceptually undesirable for engineering purposes. To characterize the possible factors affecting the consistency in seismic capacity estimates, a comprehensive parametric study is performed in an analytical manner. Theoretical derivations and graphical illustrations are resorted to facilitate the analysis. Both general and case-by-case analyses are performed to show how each of these factors affects the consistency in seismic capacity estimates. This parametric study represents a wide coverage of seismic capacity evaluating problems for nuclear facilities, and hence can be used for interpreting results of similar kinds in current engineering practice.