Traditional inservice inspection (ISI) techniques for nuclear power plants are hampered by personnel radiation exposure. There is a genuine need for on-line surveillance methods which can identify areas of possible structural degradation, thereby resulting in reduced inspection time because of concentrated inspection activity. One potential method, acoustic emission (AE) monitoring, is being investigated as a surveillance technique at Philadelphia Electric Company's Peach Bottom Atomic Power Station, Unit 3. The data produced by the AE surveillance are being compared with the ISI results.

Acoustic emission sensors are mounted on two feedwater nozzles, two core spray lines, and one recirculation by-pass line. Also, eleven mainstream safety/relief valves are being acoustically monitored for the detection and measurements of leaks. This paper describes the correspondence of the AE results with the inservice inspection data obtained during two refueling outages. The feasibility of general implementation of AE surveillance is discussed.