Plutonium analysis of high-burnup spent-fuel dissolver solutions by low-energy gamma-ray spectrometry.

摘要

High-resolution gamma-ray analysis of the isotopic abundances of plutonium in highly radioactive dissolver solutions from reprocessing plants requires separating the plutonium from the fission products. It is difficult to sufficiently purify a few milligrams (usually more) of plutonium to allow isotopic analysis in the commonly used gamma-ray energy ranges of 59--208 keV (MGA2) or 120--414 keV (FRAM). Recently, by taking advantage of the higher intensities of lower-energy gamma rays ((le)52 keV), low-energy gamma-ray spectrometry (LEGS) has measured plutonium isotopic abundances and elemental concentrations of spent-fuel dissolver solutions with burnups up to 28 000 MWD/T. To test the LEGS technique with higher-burnup spent fuels, we performed an exercise at the European Institute for Transuranium Elements at Karlsruhe, Germany. Three spent-fuel dissolver solutions with burnups ranging from 30,000 to 44,400 MWD/T were prepared and measured. Comparison of results from mass spectrometry indicates that LEGS-based methods are promising because of timeliness, simplicity, and economy.