RATU2: The Finnish research programme on the structural integrity of nuclear power plants: Synthesis of achievements 1995-1998

This Symposium summarises the scientific and technical achievements within the Finnish research programme on the structural integrity of nuclear power plants (RATU2). The programme began in 1995 and will be accomplished at the end of 1998. The annual volume of this programme represented approximately 6% of the total nuclear energy R&D in Finland. The research programme was mainly publicly funded and supplied impartial expertise for the regulation of nuclear energy. It also played an important role in the education of new experts, technology transfer and the international exchange of scientific results. The programme was organised into five research projects on the following topics: · Material degradation in the reactor environment, · Reliability of nondestructive inspections of nuclear power plants, · Structural analyses for nuclear power plant components, · Maintenance strategies and reliability, and · Fire safety. One of the main issues considered when evaluating both the safety and economic operation of the Finnish nuclear power plants was the ageing of structures and components. At the same time, ways has been sought to extend the lifetime of components. The RATU2 research programme has brought many significant scientific findings and useful applications for ensuring the reliability of NPP components. New technology has been transferred to domestic use through active international co-operation. On the other hand, international acceptance of the results has provided valuable feedback and benchmarking.