Peculiarities of the method for determination of plutonium isotopes relative quantities by means of gamma ray spectrometry

The results of measuring plutonium gamma spectrum in nuclear fuel by a high purity germanium detector are presented. It is shown that the only experimental spectrum run is sufficient for evaluation of plutonium isotope ratio in a measured sample when using the proposed methodic to calculate gamma spectrum line intensity. The 120 - 210 keV region of gamma spectrum is examined. The plutonium isotope ratio is calculated on the basis of compared gamma line intensities in the groups with the energy intervals less than 7 keV. Thus, the systematic errors caused by the self absorption effects are negligible. The method can be used for investigation of Pu isotopic composition in the spent fuel, nuclear waste and specially prepared natural samples. (author)