Abstract: In a method for ascertaining the deformation of a fuel assembly in a pressurized-water reactor, the fuel assembly is placed in a measurement station located inside a flooded pool. The measurement station has a holding apparatus for accommodating and fixing the fuel assembly and also a camera which can be moved at least approximately parallel to its bearing axis. Digital images of the fuel assembly are recorded and stored using the camera in various axial positions, in which in each case one selected structural element of the fuel assembly is located, with the position of the fuel assembly in the recorded image depending on the deformation of the fuel assembly. Each recorded image is segmented using methods of digital image processing, and the selected structural element is identified by comparison with a virtual image of the structural element.