Understanding And Mitigating Ageing In Nuclear Power Plants

Plant life management (PLiM) is a methodology focussed on the safety-first management of nuclear power plants over their entire lifetime. It incorporates and builds upon the usual periodic safety reviews and licence renewals as part of an overall framework designed to assist plant operators and regulators in assessing the operating conditions of a nuclear power plant, and establishing the technical and economic requirements for safe, long-term operation. Understanding and mitigating ageing in nuclear power plants critically reviews the fundamental ageing-degradation mechanisms of materials used in nuclear power plant structures, systems and components (SSC), along with their relevant analysis and mitigation paths, as well as reactor-type specific PLiM practices. Obsolescence and other less obvious ageing-related aspects in nuclear power plant operation are also examined in depth. Part one introduces the reader to the role of nuclear power in the global energy mix, and the importance and relevance of plant life management for the safety regulation and economics of nuclear power plants. Key ageing degradation mechanisms and their effects in nuclear power plant systems, structures and components are reviewed in part two, along with routes taken to characterise and analyse the ageing of materials and to mitigate or eliminate ageing degradation effects. Part three reviews analysis, monitoring and modelling techniques applicable to the study of nuclear power plant materials, as well as the application of advanced systems, structures and components in nuclear power plants. Finally, Part IV reviews the particular ageing degradation issues, plant designs, and application of plant life management (PLiM) practices in a range of commercial nuclear reactor types. With its distinguished international team of contributors, Understanding and mitigating ageing in nuclear power plants is a standard reference for all nuclear plant designers, operators, and nuclear safety and materials professionals and researchers. Introduces the reader to the role of nuclear power in the global energy mix Reviews the fundamental ageing-degradation mechanisms of materials used in nuclear power plant structures, systems and components (SSC) Examines topics including elimination of ageing effects, plant design, and the application of plant life management (PLiM) practices in a range of commercial nuclear reactor types

This publication provides a common internationally agreed basis on what constitutes an acceptable ageing management programme, as well as a knowledge base on ageing management for the design of new plants and design and safety reviews, and aims to serve as a roadmap to available information on ageing management. It addresses ageing management of passive and active structures and components for water moderated reactors that can have an impact, directly or indirectly, on the safe operation of the plant and that are susceptible to ageing degradation. The information provided is relevant for plants under normal operation, for plants considering long term operation, as well as for new plants including new designs. It underlines that ageing management should be implemented from the start of operation of nuclear power plants and that adequate provisions to facilitate effective ageing management should be made during the plant design, construction, commissioning, operation, and decommissioning.

This publication is one in a series of reports on the assessment and management of ageing of major nuclear power plant (NPP) components. Current practices for assessment of safety margins (fitness for service) and inspection, monitoring and mitigation of ageing related degradation of selected concrete structures related to NPPs are documented. Implications for and differences in new reactor designs are discussed. This information is intended to help all involved directly and indirectly in ensuring the safe operation of NPPs, and also to provide a common technical basis for dialogue between plant operators and regulators when dealing with age related licensing issues.

This technical report, one of a series on the management of ageing nuclear power plants, presents methodologies for selecting plant components important to safety whose ageing should be assessed and for performing ageing management studies. Although the report has been developed for the management of ageing of plant components important to safety, the methodology studies are applicable to components important to plant life.

This report updates the IAEA's findings relevant to significant ageing mechanisms and degradation locations, as well as current practices for the assessment and management of the ageing of pressurised water reactor (PWR) pressure vessel internals (RVI's). This includes irradiated assisted stress corrosion cracking of baffle former bolts, and new operational experience and practices designed to manage these problems. The report emphasises safety aspects and also provides information on current inspections as well as on monitoring and mitigation practices for managing the ageing of PWR RVI's.

The median age of nuclear power plants connected to the grid worldwide is increasing. Ageing management has become an important issue in ensuring the availability of required safety functions throughout the service life of a plant. This Safety Guide provides recommendations on meeting the requirements for safe long term operation and identifies key elements of effective ageing management for nuclear power plants.

Provides information on ageing, obsolescence and performance monitoring of those items of instrumentation and control equipment that are classified as safety equipment and/or safety related equipment, are operated in harsh environments in NPPs, and are important to plant life extension.