Plant Life Extension

The plant life extension can be defined as "the systematic evaluation of important plant systems and components to identify means to detect, monitor and trend, prevent and mitigate the effects of age-related degradation through changes in hardware, operation, maintenance and surveillance to ensure safe and economic operation during the life extension period in order to provide technical justification for licence manual". A fracture mechanics approach is widely used to project remaining life. This approach is based on assumptions about the absence of flaws.

NDT can help in establishing the confidence level of these assumptions by finding that there are really no flaws present or, if present, what are their types, sizes and locations in the tested components. In the presence of this information the fracture mechanics analyst can decide how far can a particular component still be used. Using NDT therefore for frequent monitoring of the equipment for a suitable period could produce indications of whether or not the operating conditions had been placed too near the failure line. There may be sufficient economic justification for increasing the load or extending the life, provided that it can be done without catastrophic consequences. The reliability of data generated by NDT is important in plant life extension studies. Credibility lost by different results under identical conditions on the same component is difficult to regain. NDT practitioners are being challenged to increase the level of precision of equipment and technique to meet the requirement of plant life extension, not only in the nuclear power industry, but also in other industrial sectors