US 12,437,889 B2
System and procedure for inspection of the surface of a nuclear fuel rod for the automatic detection, location and characterization of defects
Jesús Castaño Marcos, Madrid (ES)
Assigned to ENUSA INDUSTRIAS AVANZADAS, S.A., S.M.E, Madrid (ES)
Appl. No. 18/553,664
Filed by ENUSA INDUSTRIAS AVANZADAS, S.A., S.M.E, Madrid (ES)
PCT Filed Dec. 23, 2021, PCT No. PCT/ES2021/070933
§ 371(c)(1), (2) Date Oct. 2, 2023,
PCT Pub. No. WO2022/207946, PCT Pub. Date Oct. 6, 2022.
Claims priority of application No. ES202130293 (ES), filed on Mar. 31, 2021.
Prior Publication US 2024/0404719 A1, Dec. 5, 2024
Int. Cl. G21C 17/06 (2006.01); G01N 21/95 (2006.01)
CPC G21C 17/06 (2013.01) [G01N 21/95 (2013.01); G01N 2201/121 (2013.01); G01N 2201/126 (2013.01)] 10 Claims
OG exemplary drawing
 
1. A system for inspection of a surface of a nuclear fuel rod for automatic detection, location and characterization of surface defects, the rod having a longitudinal axis, the system comprising:
a plurality of point cloud acquisition systems, for obtaining a plurality of profiles, along a Y-axis which coincides with the longitudinal axis of the rod, the profiles defining a point cloud, each acquisition system being composed of:
a linear laser beam,
an optical sensor,
and a point cloud acquisition card;
wherein the number of acquisition systems, No. Adq.Syst., is given by the relationship:
No. Adq.Syst.=f(Ørod)=└3+0.1Ørod┐,
wherein └. . . ┐ denotes rounding to the nearest integer;
wherein Ørod is the diameter of the nuclear fuel rod to be inspected;
translation means for the nuclear fuel rod;
wherein the system also comprises a processor capable of:
transforming the point cloud into a height map representing a Z coordinate along a Z-axis perpendicular to a Y axis,
carrying out a local thresholding for a segmentation of the height map, and obtaining a plurality of discontinuities in said map;
classifying the plurality of discontinuities in different geometric shapes to obtain defects, wherein obtaining the defects comprises obtaining area, length, width, position and orientation of the defects,
projecting the defects on the Y-axis to obtain a depth of the defects,
calculating, starting from the projection of the defects on the Y-axis, -an equivalent function and a second derivative thereof to obtain points where the depth of the defect is maximized.