Extending the life of light water reactors

Life extension of nuclear power plants is becoming increasingly important as existing plants advance in age especially as new sites are hard to find and it is not possible to reuse an existing site immediately. The range of possibilities for extending the service lifetime of nuclear power plants is considered with particular reference to the light water reactors of the Federal Republic of Germany. The modifications are necessary in part because safety has always to be 'state-of-the-art' under the licensing arrangements. First an analysis of the plant is made preferably ten years or so before the end of the proposed lifetime - to determine the expended lifetime of the critical components and systems and the remaining service life under certain operating conditions. Proposals for backfitting and servicing can be made which are cost beneficial. (UK)