Goal Oriented Methodology and Applications in Nuclear Power Plants

A Modern Systems Reliability Approach

Yi Xiao-Jian, Shi Jian, Mu Hui-Na

• Publisher: Academic Press
• Year: 2019
• Print ISBN: 9780128161852
• eBook ISBN: 9780128165874
• Topic: Technology & Engineering
• Subtopic: Mechanical Engineering
• Index: Technology & Engineering

Goal Oriented Methodology and Applications in Nuclear Power Plants: A Modern Systems Reliability Approach presents the latest data and research on the modern system reliability approach by GO methodology to improve the quality and reliability of nuclear power plants (NPP). Quality and reliability are two key factors which are critical to the economic success of NPPs, hence this book provides a comprehensive and systematic analysis of the latest data and research illustrated through the provision of examples and solutions, applications and problems to test comprehension. Authors Xiao-Jian, Jian and Hui-Na systematically illustrate reliability modeling, analysis, optimization allocation and assessment, and their applications in NPPs.This book, without assuming prior knowledge, presents all required information in an accessible and easily applied style. It will be particularly valuable to engineering and reliability professionals, nuclear engineering graduate students, reliability engineering specialists and nuclear energy researchers.- Presents the latest research and data in one resource, eliminating the need to consult many diverse sources- Includes examples and solutions that provide practical applications- Combines principles, applications and examples within NPPs to provide a very thorough understanding of the technological aspects presented

1

Introduction

Abstract

This chapter introduces the background to nuclear power plant reliability and information about this book, including terminology used and the book’s scope.

Keywords

Nuclear power plant reliability; history; terms and definitions; scope

Chapter Outline

Outline

• 1.1 Historical developments in nuclear power plant reliability 1
• 1.2 Need for improving reliability in nuclear power plants 5
• 1.3 Nuclear power plant reliability facts and figures 5
• 1.4 Terms and definitions 6
• 1.5 Useful information on nuclear power plant reliability 7
  • 1.5.1 Organizations 8
  • 1.5.2 Journal and magazines 8
  • 1.5.3 Books 9
  • 1.5.4 Conference proceedings 10
  • 1.5.5 Data information sources 11
• 1.6 Scope of the book 11
• References 12

This chapter introduces the background to nuclear power plant reliability and information about this book, including terminology used and the book’s scope.

1.1 Historical developments in nuclear power plant reliability

Electricity was generated by a nuclear reactor for the first time on September 3, 1948, at the X-10 Graphite Reactor in Oak Ridge, Tennessee, in the United States, which was the first nuclear power plant to power a light bulb. After the Second World War, the major goal of nuclear research in the mid-1950s was to show that nuclear energy could produce electricity for commercial use. Therefore, a second, larger experiment occurred on December 20, 1951, at the EBR-I experimental station near Arco, Idaho, in the United States. This marked the beginning of the development of nuclear power. From 1960 through 2011, the world’s nuclear capacity grew from barely 1 GW to over 350 GW. The reasons behind this massive expansion were the growth of electricity consumption, a political desire to move away from oil dependency following the oil crisis of the 1970s, and protection of the environment.

At the same time, the growth of interest in nuclear power resulted in increased concern by both power plant utilities and the general public about their operational reliability. Public opinion grew more critical of nuclear power in the mid-1970s. There was a fear of accidents and uncertainty as to the handling of radioactive waste. Criticism was heightened on March 28, 1979, when the Three Mile Island nuclear power plant near Harrisburg, Pennsylvania, in the United States suffered a series of technical errors which resulted in a partial meltdown. One reactor was destroyed, however no radioactive material leaked out and no people were injured. Even so, the accident had a major impact on the public debate and policy development. A serious nuclear accident occurred at Chernobyl in northern Ukraine in 1986. The uranium fuel became overheated and melted, the surrounding graphite ignited and large portions of the power plant exploded due to the heat and the reaction between graphite and steam. Radioactive material spread over large parts of Europe. One reason for this was that the Chernobyl reactor did not have a leak-proof containment structure surrounding the reactor, something that all existing power plants have today. Thirty people were immediately killed in the accident and 134 people received acute radiation injuries. Increased incidents of thyroid cancer have been discovered in nearby areas in the former Soviet Union and have been linked to the Chernobyl accident. Pressure around the world to phase out nuclear power increased after the accident, and Italy had closed down all of its four reactors by 1990.

Demand for electricity decreased and concern grew over nuclear issues, such as reactor safety, waste disposal, and other environmental considerations. Therefore there is a great incentive for achieving high reliability. First, and most importantly, the safety requirements of nuclear power plants are of paramount concern. Also, the very high cost of designing and constructing a nuclear power plant and the high cost associated with plant downtime (as much as $800,000 per day in power replacement cost alone) provide a strong economic incentive toward designing-in, or improving, equipment reliability. Furthermore, failures are highly visible and, if they are serious enough or occur frequently, they can affect the whole industry. For these reasons, the nuclear industry is making a heavy commitment to safety with a special emphasis on the acquisition and operation of “high-reliability” systems and equipment.

At present, the answers to these questions are sought through the application of a relatively new engineering discipline, usually referred to as reliability engineering, which attempts to discover causes of equipment failures and to provide information to plant designers and operators on how these causes can be eliminated. A statistical approach to equipment failures and methods of system analysis, which are pertinent to reliability engineering, provides a means to evaluate the reliability of nuclear power plant systems and to contribute to increased plant safety and availability.

With the development of nuclear power plants, reliability engineering has evolved through three main stages.

The first period was from 1954 to 1974. About seven reactors were started construction each year until 1965, but by 1970, the construction of nuclear power plants was accelerated, and the following year construction on as many as 37 reactors had started. At the same time, the first oil shock of 1973/74 gave the growth rate additional momentum. In this period, reported plant availability was lower than expected or required. The average load factor for the plants in operation in 1973 was around 62%, which is much lower than the target figure of 80% usually assumed in nuclear power studies. Plant availability has been affected adversely by the failures of components and systems which are not safety significant but that are responsible for reliable power production. This has resulted primarily in economic losses. The main efforts to improve reliability have been oriented toward systems and components which are production related through quality control, failure modes and effects analysis, and redundancy management.

The second period was from the late 1970s to the mid-2000s. In this period, the development of nuclear power was marked by a slowdown. Globally, an average only two to three reactors were built per year by the end of this period. This downturn was initially triggered by the high construction costs of nuclear plants, and then exacerbated by a collapse in oil prices. Delays and/or cancellations in nuclear projects were aggravated by the availability of inexpensive, modular, and highly efficient combined-cycle turbines, along with market deregulations in many countries. Further suspensions and cancellations were prompted by the accident at Three Mile Island (United States, 1979), which caused enormous public concern about nuclear safety and further complicated the regulatory process. Activities were further depressed by a second disastrous nuclear accident at the Chernobyl nuclear power plant (Ukraine, 1986). And the resulting slowdown was further amplified by low energy prices throughout much of the 1980s and 1990s. These made the risks of the higher capital investment needed to build nuclear power plants even less attractive. In this period, the main efforts to improve reliability began to orient toward systems and components which are safety related.

Although several methods for reliability analysis were in use in this period, probability risk analysis, in particular the fault tree representation method, proved to be the most convenient. This has been recently reaffirmed by studies such as the Rasmussen Report. The characteristics of this method of analysis can be summarized as:

• • System analysis for preparation of a physical and functional description of the analyzed system, accompanied by the formation of system-tree diagrams.
• • Reliability analysis which embodies the formation of appropriate mathematical models, and determination of model parameters.
• • Safety-related analysis, release-risk assessment, whereupon improvement of the reliability of components and systems design may be required.

However, the weak point in these analyses is the scarce k...

Table of contents

• Cover image
• Title page
• Table of Contents
• Copyright
• Dedication
• Preface
• 1. Introduction
• 2. Goal-oriented methodology
• 3. Reliability modeling and analysis method for nuclear power plants by the goal oriented method
• 4. Reliability optimization allocation method for nuclear power plants by the goal oriented method
• 5. Reliability assessment method for nuclear power plants by the goal oriented method
• 6. Reliability software design based on the goal-oriented method for nuclear power plant
• 7. Applications of reliability modeling and analysis by the goal oriented method
• 8. Application of reliability optimization allocation by the goal oriented method
• 9. Application of reliability assessment by the goal oriented method
• Index