Patent ID: 8453514

Claim:
A method for measuring a deformation of a fuel assembly in a pressurized-water reactor having a plurality of control-rod guide tubes, which comprises the steps of: inserting a probe, being displaceable in a direction of a longitudinal axis of a control-rod guide tube, into an interior of the control-rod guide tube, the probe having at least one reference axis and is supported in at least one section of the control-rod guide tube against an inner wall of the control-rod guide tube such that an orientation of the at least one reference axis uniquely depends on an orientation of the longitudinal axis of the control-rod guide tube in the at least one section, and the orientation of the at least one reference axis in the at least one section of the control-rod guide tube relative to the orientation of the longitudinal axis or of another reference axis of the probe in another section of the control-rod guide tube is ascertained.