Many utilities are making the decision to increase the interval between routine inspections and maintenance outages for their steam turbines and generators. Similarly, they are also taking steps to decrease the length of the outages required to perform important maintenance tasks. Increasing the interval between outages increases the risk that problems may occur and go undetected, possibly causing serious damage that would result in added maintenance costs and increased outage lengths. In-situ inspection technology would facilitate turbine condition assessment without incurring the cost of unit disassembly. It would also support a condition-based maintenance approach and provide information to aid in planning for future outages. EPRI has begun a program to identify, develop, and verify state-of-the art and innovative in-situ techniques for inspection of steam turbines without major disassembly. This paper provides an overview of activities undertaken to date in support of this program.
