Determination of the Pu240/Pu239 ratio by alpha spectrometry using the WinALPHA program

The isotopic ratio of 240Pu to 239Pu is an important parameter in identifying the origin of plutonium in a given radioactive sample. High-resolution mass spectrometry is generally accepted as an accurate technique for determining this ratio, but this is a very costly method. Alternatives to this method are alpha- and gamma-spectrometry studies but the problem with these low-cost method lies with the analysis of the spectrum. Recently, Noy et al. [2004. Nucl. Instrum. Methods in Phys. Res. A 525, 522–528] developed a computer program code called WinALPHA to quantitatively analyze the alpha spectrum; the program is available from the IAEA website. In this paper, we report the results obtained from the analysis of the alpha spectrum of plutonium from power bearing product samples from power reactor fuel reprocessing plant using the WinALPHA program. The results are found to be in good agreement (within 1–2%) with results from mass spectrometry.