Sound measurements to detect cavitation phenomena in reactor coolant pumps

As the early detection of cavitation phenomena in pumps of coolant circuits by monitoring the hydraulic data of the pumps is not possible, and as an analysis of the sonic signals stimulated at the pump by cavitation is complicated by the interference of the pump-inherent noise spectrum, the analyses are first carried out on a special cavitation pipe section and are then compared with measurement on a pump. For sound sensors a quartz crystal diaphragm pressure sensor and a piezo-ceramic sensor with sound conductor are used. In order to be able to record the cavitation phenomena at the same time visually and by measurement the testing device and the pump consisted of acrylic glass resp. glass. Characteristic power density spectra as a function of the cavitation number of the cavitation charge until void formation are given. (ORU)