device to check the dimensions of brennelementes for nuclear reactors

摘要

A method for checking the dimensions of a nuclear reactor fuel assembly in a water tank uses two mutually parallel probes each having a first probe side carrying an ultrasonic test head at a free end thereof with acoustic directions directed towards each other and each having a second probe side facing away from the ultrasonic test head. The acoustic waves are transmitted with one of the ultrasonic test heads, the transmitted acoustic waves are received with the other ultrasonic test head, one of the second probe sides is brought into contact with a given region of the fuel assembly to be checked, the probes are moved towards each other in the direction of the acoustic waves due to contact pressure with the fuel assembly, the probe movement is indicated and assessed by a reduction of transit time of the acoustic waves between the test heads, and the actual dimension of the fuel assembly region to be checked is derived while accounting for the dimension of probe movement.