| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a crack diagnostic method of a reactor structure for achieving miniaturization, and for accurately diagnosing the existence of a crack even when an inspection object site exists at a narrow part. <P>SOLUTION: An excitation device 16 is mounted on reactor core spray piping 4 installed in a nuclear reactor pressure container 1, and welded in a nuclear reactor nozzle by using a fixing arm 18 and a movable arm 20. A weight 24 is mounted on a rotary shaft 26 at a position which is different from the position of the center of gravity of the weight 24. The reactor core spray piping 4 is excited due to repeated loads by driving the motor 25 to rotate the weight 24. An accelerator meter 29 measures the characteristic frequency of the excited reactor core spray piping 4, and the characteristic frequency is input to a signal processor 35. The signal processor 35 compares the measured characteristic frequency with the characteristic frequency of the reactor core spray piping 4 in a state that any crack does not exist at the inspection object site, and diagnoses the presence/absence of the crack at the inspection object site. <P>COPYRIGHT: (C)2012,JPO&INPIT |
