A typical alloy nuclear fuel plate contains fissile Al-U alloy uniformly dispersed in non-fissile Al matrix. A conventional X-ray radiograph of the fuel plate provides an image of varying grey level corresponding to the alloy distribution in the matrix. As unaided eye has limitation in resolving all the grey levels present in such an image, a colour difference in place of grey tones would benefit the homogeneity evaluation due to increased visual perception.

Colour photographic films have been used in combination with fluorescent and fluorometallic intensifying screens. Low kV X- ray source (<80 kV) was used and the films were processed in Kodak-C41 colour developer to obtain radiographs of different colour hue in terms of object structure. A colour flash of suitable intensity was provided during the film processing to get the optimum result. Experiments were carried out by interrupting the development process to provide colour flash and by using various x-ray exposures to standardize the technique.

This paper describes the development of a film based x-ray colour radiography technique, its application in the homogeneity evaluation of Al-U alloy nuclear fuel plates and the experimental details of the colour radiograph processing. Typical colour radiographs obtained during the standardization and the fuel homogeneity evaluation are also illustrated.