Isotopic ratio correlation for the isotopic composition analysis of plutonium in Am–Pu mixed samples having High americium content

• Effect of high Am in the determination of isotopic composition of Pu was studied.
• γ-spectra in a wide Am–Pu range (5–97% Am) were simulated by Monte-Carlo method.
• 241Am is found to suppress the γ-rays of 238Pu and 240Pu.
• Isotopic ratio correlations are proposed for isotopic composition analysis.

Interference of high amount of americium in the plutonium isotopic composition analysis has been studied by simulating gamma-ray spectra for Am–Pu samples over a wide composition range (5–97% 241Am) for both power and research reactor grade plutonium. An alternate way for isotopic composition analysis has been proposed by correlating the isotopic ratios available in our old database with the experimentally obtained 241Pu/239Pu isotopic ratio. The proposed method has been validated using simulated spectra of known isotopic compositions.