Strategy for determining life expectancy in mechanical components in an overall system

The safety standard at a nuclear power station achieved at the time of commissioning on the basis of the state of the art during the design and construction stage has to be maintained over the entire working life of the unit. Original design life expectancy is under review in the light of new safety experience and developments. The results of such analysis can serve not only preventive maintenance purposes but also as the basis for supporting and extending the planned or approved working life; they help increase availability. A comprehensive analysis strategy to establish the actual condition and residual life expectancy of components, systems and complete units has been developed by Siemens/KWU. The results of this analysis can lead to action to extend the life expectancy of components and systems and improvements in systems and subsystems. This report quotes a number of examples. 6 figs