Abstract: An improved method for assembling bundles of nuclear fuel rods which reduces damage to the fuel cladding surface as the fuel rods are passed through an array of spacers. In particular, the invention prevents or greatly reduces the severity of longitudinal scratches on the fuel rods. The method uses thin-walled metallic tubes having a wall thickness of 0.003 to 0.006 inch and a yield strength in excess of 140,000 psi. The predetermined tube thickness ensures that the tube remains elastic. The tube deflects the cell springs when inserted in the spacer cells and reduces the load exerted on the fuel rods.

Abstract: To mechanize the accumulation of nuclear fuel rods into fuel bundle groups, fuel rods are uploaded onto an input table from a succession of trays containing fuel rods of different rod types. The serial number of each fuel rod is read during procession across the input table to an output queue. An input elevator uniformly distributes fuel rods from the output queue to plural levels of an accumulation rack until each level contains an identical number of fuel rods of each rod type necessary to completely assemble one fuel bundle. An output elevator then empties the accumulation rack, one level at a time, to an output table, from which the fuel rods from each level are downloaded into separate bundle trays.

Abstract: In an automated first weld apparatus, a transporter conveys nuclear fuel cladding tubes successively to a welding station where a separate end plug is welded to an open end of each tube. Thereafter, the transporter indexes the tubes successsively through a cooldown station where the weld is cooled, to a reader station where a unique end plug serial number is read, and then to a succession of inspection stations where the internal and external weld characteristics are automatically examined. The resulting inspection data is correlated with the associated serial number for record purposes and tested against quality assurance standards pursuant to sorting the tubes into accepted and rejected lots.

Abstract: A monitor for detecting airborne radioactive particulates is disclosed. An elongate strip of filter paper is fed across first and second air inlet ports of a collection chamber. Ambient air is selectively drawn into the chamber through a selected one of the inlet ports and out an through outlet port. Particulates trapped on an area of the filter paper in alignment with the open inlet port are detected after advancing the strip area into alignment with the closed inlet port. A radiation detector mounted on a movable arm is selectively positioned over the closed inlet port to detect the trapped radioactive particulates, while a new sample is collected at the open inlet port. Exposure of the detector surface to corrosive materials is avoided and the detector can be positioned close to the filter strip to maximize counting efficiency and energy resolution. A microprocessor controls the functions of the monitor and allows continuous unattended operation.

Abstract: A probe is disclosed for detecting the absence of helical springs from an array of mutually spaced springs, each mounted on a separate shank. The probe includes an elongate arm having a pair of pawls mounted in an aperture at one end of the arm, biased to extend from the aperture. During probing, the helical springs normally prevent the pawls from assuming their extended positions outside the aperture, which is urged by the applied biasing force. If a helical spring is missing from the array, the appropriate pawl pivots outward into its extended position and becomes lodged against the springless shank to lock the probe in position. Its location in the array then indicates where a spring must be replaced.

Abstract: Transport apparatus is disclosed for moving a stream of objects along a substantially continuous path between a source and a collection station and past a viewing station. A stream of successive, spatially separated objects is moved into end-to-end abutment to form successive stacks of objects. Each stack is spiraled past the viewing station with minimal vibration to expose the complete surface of each object to inspection. Subsequently each stack is rearranged into spatially separated objects which are rapidly sorted by diverting those objects from the continuous path which do not conform to predetermined criteria upon inspection. The transport apparatus achieves high throughput without compromising the accuracy of the inspection process.

Abstract: A method and apparatus for loading nuclear fuel pellets in levels onto a horizontally and vertically indexing tray string-by-string. The apparatus includes a belt feeder assembling each string at a location on pivotal blades over the tray. Arrival is optically noted and a pusher delivers the string to a drop site, completely loading the string onto the blades for delivery to the indexing tray.