This publication provides detailed information for operating organizations of research reactors on methodologies to manage existing and potential ageing effects and the degradation of structures, systems and components. Practical guidance is presented on managing the effects of ageing on civil structures, on mechanical, electrical and instrumentation and control systems, and on reactor components important for safety and operation. This publication also provides information on how to establish and implement an effective and systematic ageing management programme, including the management of modifications, modernizations and refurbishments. Several practical examples of successful ageing management programmes executed in operating research reactors are included as annexes.