METHOD AND DEVICE FOR MEASURING THE THICKNESS OF AN OXIDE LAYER ON THE PENCIL CLADDING IN A FUEL ASSEMBLY

摘要

The invention concerns a method which consists in: moving a measuring head (8a) of the probe (8) along the length of a gap (12) between two rows of pencils (4) and in its extension on either side of the passage gap (12) and of the pipe provers, in an outgoing direction and in a return direction opposite to the outgoing direction; collecting and transmitting the probe signal in digital form to a computing unit (18) comprising a software for processing the signal and for determining the thickness of an oxide layer on the outer surfaces of the pencils (4); determining the minima of the probe (8) signal during its displacement in the passage gap between the rows of pencils (4); adjusting a calibration curve based on the minima values of the signal of the probe in contact with the calibration pencils; determining the thickness values of the oxide layer corresponding to the signal minima, based on the calibration curve; verifying the coherence of the thickness values obtained for each of the pencils of the row of pencils in the outgoing direction and in the return direction of the probe (8) displacement and recording and displaying the coherent thickness values of the oxide layer for each of the pencils (4).