Determination of Actinide Isotopic Composition: Performances of the IGA Code on Plutonium Spectra According to the Experimental Setup

The IGA code (a French acronym standing for actinides gamma isotopy) is a tool developed by the CEA LIST to determine the isotopic composition of plutonium and uranium, based on the automatic analysis of the γ/X spectrum emitted by a nuclear sample. Its main feature is its generic approach of the problem. As a consequence, the IGA code is a very flexible tool, because no particular experimental setup is imposed to the user for the acquisitions, in terms of energy range, gain, channel number or detector resolution. However, these experimental conditions can have an impact on the quality of the results. So, a study has been carried out to evaluate the effect of different experimental parameters on the IGA performances for plutonium spectra and quantify these performances. The study has been led according to three different approaches: analysis of IGA results on a whole spectrum database coming from French laboratories, analysis on artificially modified spectra and finally analysis of results on new real spectra acquired in the laboratory on certified samples.