FUEL ROD BREAKAGE IDENTIFICATION METHOD BY ULTRASONIC WAVE, AND INSPECTION PROBE

摘要

PPROBLEM TO BE SOLVED: To provide an identification method of a broken fuel rod capable of identifying the broken fuel rod, regardless of the surface state of the fuel rod. PSOLUTION: This method has a process of measuring each distribution of a peak value of the n-th bottom surface echo, having a sufficient difference between a sound fuel rod and a broken fuel rod relative to an echo height value, which is a bottom surface echo after the first surface echo, which does not overlap with echoes after the second surface echo, and of the number of fuel rods, relative to the plurality of fuel rods, and defining its frequency distribution; a process of calculating a peak value, corresponding to the n-th bottom surface echo of the broken fuel rod from the median of the frequency distribution, defining the frequency distribution of the peak value of the n-th bottom surface echo of the broken fuel rod, by applying a frequency distribution of the peak value of the n-th bottom surface echo of the sound fuel rod to the median, and calculating a broken fuel rod peak value range; and a process of measuring the peak value of the n-th bottom surface echo of an inspection object fuel rod, comparing it with the broken fuel rod peak value range, and identifying the broken fuel rod. PCOPYRIGHT: (C)2008,JPO&INPIT