An improved method for the non-destructive characterization of radioactive waste by gamma scanning

A method to improve the reliability and accuracy of activity results in segmented gamma scanning of radioactive waste drums with non-uniform isotope and matrix distribution has been developed. The improved method which is based on numerical simulations of the measured angular dependent count rate distribution during drum rotation in segmented gamma scanning has been validated through the measurement of Cs-137 and Co-60 activities in 13 real radioactive waste drums with heterogeneous activity and matrix distributions. The results were compared to that obtained for the conventional method assuming homogeneous activity and matrix distributions.