Nuclear Fuel Rod Displacement Measurement using a Wide-Area CCD Sensor

In this paper, a displacement measurement technology is described for nuclear fuel rod using COTS (commercial off-the-shelf) wide area CCD sensor. The displacement measurement system include Nikon D80 digital camera having a wide area CCD sensor (size: 23.6x15.8mm, pixels: 3872x2592), telescopic zoom lens(75 - 300mm) to capture the image at the distance as far as possible, semiconductor laser marker, and optical accessories. The basic idea of the displacement measurement is to illuminate the outer surface of the fuel rod with collimated laser spot beam at an angle of 45 degrees. The relative motion of fuel rod in the horizontal direction causes the illuminated laser spot beam to move vertically along the surface of the fuel rod as much as the same displacement in the horizontal direction. The resulting change of laser spot position in the surface of the fuel rod is imaged by means of a high definition wide-area CCD camera. The comparison and subtraction of the two images, taken before and after the micro movement of the fuel rod, reveals the measures of the displacement of the fuel rod. In this paper we shows result for the displacement measurements of the nuclear fuel rod using both the high definition wide-area CCD sensor and image processing technology