Evaluation of performance of gamma tomographic technique for correcting lump effect in radioactive waste assay

A model for estimation of the lump e€ect, especially for plutonium, in the tomographic technique is given, based on simulating a measurement system to assay radioactive waste drums. The results show that the tomographic technique can be successfully used for mea- suring heterogeneous waste drums containing lumps. When the dimensions of a pixel are chosen equal to 1 cm, the errors are not larger than 27% for a lump of plutonium metal.