method for checking the dimensions of a brennelementes for nuclear reactors

摘要

A method for checking the dimensions of a fuel assembly for nuclear reactors formed of a bundle of longitudinally extended fuel rods disposed in rows in a water tank defining gaps between the rows includes moving two mutually parallel probes with respective ultrasonic test heads at free ends thereof relative to the fuel assembly, inserting the probes laterally into the gaps between the fuel rods accommodating a row of fuel rods between the probes, transmitting ultrasonic waves with one of the ultrasonic test heads, receiving the ultrasonic waves with the other ultrasonic test head, continuing irradiation during the movement of the probe, determining at least one of the height and width of a peak of the ultrasonic waves associated with a water path between the transmitting and receiving test heads, and using at least one of the height and width of the peak to determine the spacing between two fuel rods.