Rod examination gauge

Abstract

The present invention is directed to a semi-automatic rod examination gauge for performing a large number of exacting measurements on radioactive fuel rods. The rod examination gauge performs various measurements underwater with remote controlled machinery of high reliability. The rod examination gauge includes instruments and a closed circuit television camera for measuring fuel rod length, free hanging bow measurement, diameter measurement, oxide thickness measurement, cladding defect examination, rod ovality measurement, wear mark depth and volume measurement, as well as visual examination. A control system is provided including a programmable logic controller and a computer for providing a programmed sequence of operations for the rod examination and collection of data.

We claim: 
     
       1. A rod examination gauge comprising: vertical elevator means,   support platform means mounted at the top of the elevator frame means for supporting a fuel rod,   rod guide means mounted at the bottom of the elevator frame means for guiding the fuel rod,   storage rack means arranged at the bottom of the elevator frame means for storing instruments means, and   instrument table means mounted on the transfer carriage of the elevator means for holding instruments means for measuring the fuel rod and a closed circuit television camera for viewing the fuel rod.   
     
     
       2. The rod examination gauge of claim 1, wherein the instruments means include axial profilometer means for measuring fuel rod diameter and oxide thickness, orbiting profilometer means for measuring fuel rod wear mark depth and volume and fuel rod ovality, and ultrasonic instrument means for detecting rod cladding defects. 
     
     
       3. The rod examination gauge of claim 2, wherein the axial profilometer means includes a roller assembly means for aligning and positioning the fuel rod in the center of the axial profilometer means, and a drive assembly means connected to DC motor for driving the roller assembly through a pressured and watertight junction box. 
     
     
       4. The rod examination gauge of claim 3, wherein the axial profilometer means includes a magnescale probe assembly for measuring the diameter of the fuel rod. 
     
     
       5. The rod examination gauge of claim 4, wherein the axial profilometer means includes an eddy current probe means for measuring the fuel rod oxide thickness. 
     
     
       6. The rod examination gauge of claim 2, wherein the orbiting profilometer means includes a roller assembly means for gripping and centering the fuel rod, and a rotary platform means driven by a DC motor for driving the roller assembly. 
     
     
       7. The rod examination gauge of claim 6, wherein the orbiting profilometer means includes a magnescale probe assembly for measuring fuel rod wear marks and rod ovality. 
     
     
       8. The rod examination gauge of claim 2, wherein the ultrasonic instrument means includes a roller assembly means for gripping and maintaining the fuel rod at the center of the ultrasonic instrument means. 
     
     
       9. The rod examination gauge of claim 8, wherein the ultrasonic instrument means includes a longitudinal transducer and a circumferential transducer, each driven by a motor for providing x- and y- directional orientation thereof. 
     
     
       10. The rod examination gauge of claim 1, wherein the support platform means includes standard bars of different rod diameters for calibrating the instruments means. 
     
     
       11. The rod examination gauge of claim 10, wherein the support platform means is arranged to receive a rod caddy means for holding and transporting a fuel rod. 
     
     
       12. The rod examination gauge of claim 11, wherein the support platform means include a rod rotator motor means for providing angular orientation of a fuel rod therein, and storage support means for storing the standard bars and for holding the rod caddy. 
     
     
       13. The rod examination gauge of claim 10, wherein a rod suspension assembly is provided for holding the fuel rod, the rod suspension assembly including a suspension device, a secondary drop protection wire, and collet means for grasping fuel rod. 
     
     
       14. The rod examination gauge of claim 13, wherein the rod suspension device includes a drive shaft coupler having a coupler slot for engaging the rod rotator motor, a universal joint, a pin, and a retainer nut, and wherein the suspension device means is tapered to fit within an examination port on the support platform means. 
     
     
       15. The rod examination gauge of 14, wherein the collet means includes a J-slot associated with a spring for accepting the pin of the rod suspension device, and fingers for accepting the fuel rod.