Preventing Condenser Tube Failures Through Effective Cleaning and Nondestructive Testing

Generating companies lose hundreds of millions of dollars annually to problems related to condenser and heat exchanger fouling, corrosion and tube leaks. In fact, the Condenser Tube Failure Control Program of Electric Power Research Institute (EPRI, Matthews, J.) disclosed that condenser tube failures contributed to almost 25,000 outages nationwide during a recent four year period and continue to be one of the most pressing issues related to plant output and availability. To adequately prevent condenser tube failures, effective condenser tube cleaning and nondestructive testing must be performed. Effective tube cleaning should ideally remove all deposits, leaving only the cleanest metal surface. Once tubes are free of fouling deposits, multi-frequency eddy current testing should be used to establish the overall integrity of condenser tubes. Plugging is recommended for the tubes with poor integrity that put condenser reliability at risk. If tube failures do occur, advances in tracer gas leak detection, specifically those using sulfur hexafluoride and helium, can be used to quickly locate sources of circulating water tube leakage and return the unit to reliable operation. This paper will examine implications of condenser tube fouling and failure, and the available nondestructive technologies for their prevention and correction.