Reverse isotope dilution alpha spectrometry using plutionium-239 spike for determining plutonium concentration in high burn-up fuel samples without purification from americium-241 and a bulk of other impurities

A reverse isotope dilution alpha spectrometric /R-IDAS/ method using²³⁹Pu as a spike is described for the determination of plutonium concentration in high burn-up fuel samples wth²³⁸Pu/(²³⁹Pu+²⁴⁰Pu) alpha activity ratio >0.5, without resorting to any purification from²⁴¹Am and a bulk of other impurities. It involves the addition of a pre-clibrated spike solution to a known aliquot of the plutonium sample solution followed by source preparation using TEG as a spreading agent. The results obtained on a number of plutonium samples containing 20–80% of²⁴¹Am /alpha activity wise/ using this method are compared with those achieved by R-IDAS using purification with TTA, with respect to precision and accuracy. Precision and accuracy of 0.5% are demonstrated. This method eliminates the need of any separation and purification of plutonium from²⁴¹Am and a bulk of other impurities like uranium.