METHOD AND DEVICE FOR MEASURING THE DIAMETER OF A PERIPHERAL PENCIL OF A NUCLEAR REACTOR FUEL ASSEMBLY

摘要

The invention concerns a method which consists in measuring the diameter over a section of a peripheral pencil (2) of the fuel assembly between two successive spacer grids (3) which consists in: placing, at a level located between the two successive spacer grids (3), a measuring instrument (14) comprising two measuring fingers (18) with free relative displacement in a first horizontal direction (X) returned towards each other by elastic return means and extending, in a second horizontal direction (Y) perpendicular to the first horizontal direction (X); moving the measuring fingers (18) in the second horizontal direction (Y) towards the pencil (2), so as to bring into contact with two zones of the section of the pencil two contact pieces of the measuring fingers (18); moving, in the vertical axial direction of the pencil, along the section located between the two spacer-grids (3), the measuring fingers (18) and measuring the distance between the measuring fingers (18) in the first horizontal direction during the axial displacement of the measuring fingers (18), with an electromagnetic sensor.