Patent Number: 047598972
Section: abstract

An electromechanical measurement system for acquiring dimensional data from a nuclear fuel assembly includes an underwater measurement assembly, support means for mounting same on the edge of a spent fuel pool, and a control and data acquisition and processing unit. The underwater measurement assembly includes an elongated strongback disposable vertically along a pool wall, adjustment mechanism on a support assembly permitting accurate positioning of the strongback. A support plate carries hydraulic clamps for clamping the top nozzle of a fuel assembly while it is supported from overhead, a clamp carried by the lower end of the strongback being engageable with the bottom nozzle for holding the fuel assembly in a selected orientation with the faces of the top nozzle vertical. A chain/motor driven carriage moves vertically and carries a video camera and a plurality of measurement gauges movable in a horizontal plane for engaging each nozzle and grid of the fuel assembly at a plurality of points and measuring the distances of those points from fixed reference planes. A program-controlled computer calculates from the measurements the location of the center of each nozzle and grid in the measurement plane and processes this data to derive bow, twist and tilt measurements for the fuel assembly.