Wavelet transform of autoradiographs: Analysis of MOX fuel heterogeneity.

Radiation imaging is extensively applied in nuclear industry for various purposes including fuel characterization. Accurate quantitative evaluation of these radiographic images is difficult by the existing manual process and therefore image analytical methods have been attempted. The method of wavelet transform analysis has been applied on Gamma autoradiography (GAR) images of experimental (U, Pu)O mixed oxide (MOX) fuel pins with the objective to investigate the effectiveness of the method for fuel homogeneity characterization. The method was found effective to carry out quantified estimations of size and relative plutonium concentration of the heterogeneous portions in the fuel. The results were validated with theoretically simulated results as practical standards and calibrations are not possible in these samples. The results of wavelet transformation analysis were found to be more accurate with reference to the theoretically simulated values in comparison with conventional pixel analysis applied on the original GAR images.