Limit of the operation life of NPP

Ensuring the safety and reliability of ageing nuclear power plant is one of the most important tasks facing both the nuclear industry and safety authorities. As a nuclear power plant ages, its reliability and the safety margins provided by the design tend to decrease and its operation and maintenance costs are likely to increase unless an awareness of the need to manage age related degradation is imparted to and acted upon be the plant maintenance and operations personnel. In Finland the design lives of NPPs will be reached in the time period from 2008 to 2020. Ageing management can best be accomplished by a comprehensive multi-disciplinary management programme. The main objective of such an ageing management programme is to ensure that significant ageing mechanisms and their effects are detected and mitigated in a timely manner so as to ensure continued and reliable plant operation. (orig.)