| 摘要 |
PURPOSE: To detect the lowering of function of a foreign matter detecting apparatus, by producing a shock sound forcibly on a housing of a nuclear reactor pressure receptacle or a vapor generator by a shock giving instrument and comparing this shock sound with the characteristic of preliminarily memorized shock sound. CONSTITUTION:Shock sounds are produced by operating shock giving instruments 81-8n and these shock sounds are detected by sound detectors 31-3n. The detected waveform is analyzed by a characteristic extractor 9 provided with a microcomputer and the analyzed results are compared with the comparison data of shock given on the same place and then, whether there is a difference more than the set value or not is examined. If anything unusual occurs in a course from the sensor 3 to a filter 5, the detected signal of an abnormal detection system is varied to a low crest value. Also, the variation of the same tendency appears on the whole detected signal if there is anything unusual about the instruments 81-8n. |
