Apparatus for assembling and welding end plugs to nuclear fuel cladding tubes and inspecting the end plug welds on an automated basis

Automated apparatus for welding a separate end plug to one open end of each of a succession of nuclear fuel cladding tubes and for inspecting each end plug weld, said apparatus comprising, in combination:

• A. a welding station including
• (1) a supply of end plugs,
• (2) end plug handling means for picking individual end plugs from said supply for mating with one open end of each tube successively presented to said welding station, and
• (3) a welder operating to weld the mated end plug to the tube;
• B. a cooldown station for cooling each end plug weld in an inert gas atmosphere;
• C. a serial number reader station for reading a unique serial number inprinted on each end plug;
• D. a first weld inspection station for inspecting each end plug weld and for generating first weld inspection data indicative of the weld internal characteristics;
• E. a second weld inspection station for inspecting each end plug weld and generating second weld inspection data indicative of the weld external characteristics;
• F. a computer system linked with said serial number reader and said first and second weld inspection stations, said computer system operating to correlate said first and second weld inspection data with the associated end plug serial number for each end plug weld and processing said inspection data to determine whether each end plug weld meets established engineering standards pursuant to issuing appropriate accept/reject signals in correlation with the associated end plug serial number;
• G. an input queue for holding a plurality of tubes;
• H. a tube transporter for periodically picking individual tubes from said input queque and conveying the tubes in a direction transverse to their tube axis in indexing steps to index positions respectively axially aligned with said welding, serial number reader, and first and second weld inspection stations, said tube transporter including separate drive means positioned at said index positions for axially reciprocating the tubes into and out of said welding, serial number reader, and first and second weld inspection stations;
• and
• I. a sorter positioned at an output end of said tube transporter and operating in response to said accept/reject signals from said computer system to sort the tubes successively transported thereto into separate accept and reject lots.