Determination of ²³⁸Pu content in plutonium using gamma-ray spectrometry

PuO₂ have been widely used as an important power source for deep space exploration. In order to accurately calculate the amount used and design the shielding structure In the use of raw materials, it is necessary to clarify the species and contents of radionuclides contained the raw materials. In this paper, the γ-ray spectrum of the heat source grade plutonium raw material a sealed container was determined by high-purity germanium (HPGe) γ spectrometer; the γ-ray energy spectrum was analyzed to determine the main radionuclide species in the raw material; The detection efficiency of the 1001.03 keV γ-ray under the measurement conditions was calculated by the Monte Carlo program MCNPX. According to the measurement and calculation, the activity of ²³⁸Pu is 4.76 × 10¹² Bq in the heat source grade plutonium raw material, which is less than 2% than calorimetry. (authors)