Estimation of plutonium present in 200 litre waste drums containing high amount of beta gamma activity

The segmented gamma ray scanning system developed for the assay of plutonium present in 200 L waste drums was modified for the estimation of gram amounts of plutonium in the presence of high beta gamma activity. A multi gamma ray source of 152Eu having ~1 mCi activity was used for the determination of attenuation correction factors for high count rate drums. Dead time corrections were applied to arrive at the corrected count rates for all the gamma rays. Present study has shown that the estimation of ~1 g of 239Pu in a waste drum can be carried out in the presence of 137Cs up to an activity level of 20 mCi.