Determination of 242Pu mass fraction in plutonium samples using isotopic correlation method. Method adaptation for plutonium from Russian reactors.

Isotopic correlation method which is used in gamma-spectrometry serves as most widespread method for Pu-242 abundance determination. Since these correlations depend on reactor type and nuclear fuel irradiation history, search of unified correlation for all types materials is a very difficult task. Isotopic correlations method that was implemented in MGA and FRAM codes had been developed for plutonium from spent nuclear fuel of BWR and PWR reactors and showed quite good results. In Russia reprocessing of spent nuclear fuel from VVER-440 and BN-600 reactors and plutonium extraction are carried out at RT-1 Plant of PA “Mayak”. In this article authors present the results of investigation on adaptation of isotopic correlations method for plutonium from Russian reactors. For this purpose isotopic composition measurements for number of plutonium sample were carried out using MGA and FRAM software. Obtained results were compared with mass-spectrometry data. Also we have processed the data array on isotopic composition of various plutonium samples in order to obtain appropriate coefficients are being used in isotopic correlation method. These coefficients can be accepted as recommended values for MGA and FRAM codes for determination of 242Pu abundance in plutonium from Russian reactors.