Patent Number: 047284838
Section: abstract

An apparatus for an integrated and automated fuel assembly inspection system includes a support base, an elongated fixture, top and bottom carriages and a pedestal. The top carriage is mounted to a pair of tracks on the fixture for vertical movement therealong. The pedestal is mounted on the base and aligned with the top carriage for supporting a nuclear fuel assembly therebetween. The bottom carriage has a central opening adapted to receive the fuel assembly therethrough such that the bottom carriage surrounds all sides of the fuel assembly. Also, the bottom carriage is mounted to the tracks for generally vertical movement along the fixture and the fuel assembly. D.C. stepping motors are mounted on the top and bottom carriages and coupled to a gear track for selectively driving the carriages along the fixture. Proximity sensors are movably disposed on the bottom carriage adjacent the sides of the fuel assembly for measuring its envelope when the bottom carriage is moved to and stationed at selected axial positions along the fuel assembly. Lasers and photodetectors are disposed on the top and bottom carriages for continuously monitoring fixture out-of-straightness and performing correction. Capacitive probes are disposed on the bottom carriage for measuring channel spacing between fuel rods of the fuel assembly, and photoswitches and an optical scale are disposed on the bottom carriage and the fixture for measuring fuel assembly length when the bottom carriage has been moved between the bottom and top nozzles of the fuel assembly.