Examples of high cycle thermal fatigue (HCTF) damage cases on
PWR austenitic stainless steel components are reported. High cycle
thermal fatigue risk is primarily due to mixing of cold and hot water,
unexpected leaks of cold water through check valves or to turbulent
penetration of hot water running in a main pipe into a connected line.
When such thermal fatigue issues are identified in PWR power
plants, manufacturing improvement such as inner surface polishing
of austenitic stainless steel parts can be performed to increase the
fatigue resistance of the components.