A study of in-line plutonium isotopic analysis for gaseous plutonium hexafluoride

In-line plutonium isotopic analysis of gaseous plutonium hexafluoride (PuF/sub 6/) is very important for process control and special nuclear material accountability in any plutonium isotope separation process that requires a gaseous phase. Although much effort had been devoted to analyze arbitrary plutonium samples, no isotopic analysis had been done on gaseous PuF/sub 6/ samples. The authors have initiated a study on the use of a high-resolution, gamma-ray spectroscopy technique to analyze gaseous plutonium hexafluoride. For the first time, PuF/sub 6/ gas samples with pressures varying from 0.15 to 31 torr, which were directly fed into a gas cell from a process flow loop, were measured. The isotopic results of these measurements of gaseous PuF/sub 6/ agree very well with those of mass spectrometry measurements of solid PuF/sub 4/. The precision of a 10-min measurement of a 10-torr reactor-grade PuF/sub 6/ is 1.5% for /sup 238/Pu, 0.22% for /sup 239/Pu, 0.87% for /sup 240/Pu, and 17.5% for /sup 241/Pu