DESIGN BASIS RECONSTITUTION

Backfitting measures serve to bring nuclear power plants up to the cur rent state of the art. This applies to safety standards in particular. However, the same process can also be used to pass on technical know- how from a power plant team to a new generation of young plant enginee rs and technicians by way of practical design and commissioning work. Nuclear power plants originally were designed for an operating life of thirty to forty years. Backfitting keeps older nuclear power plants a t a ''young'' level, thus allowing the useful life of plants to be ext ended greatly, and justifying unlimited operating permits to be grante d. Experience in operating nuclear generating units, and arising from accidents, is evaluated, and identical plants are rendered safer by ba ckfitting. Detailed programs of this kind are under way in Sweden for the plants of Barsebeck, Forsmark, Oskarshamn, and Ringhals.