HPLC separation of REE, U and Pu from uranium silicide fuel

Experimental burn-up determination of spent nuclear fuel samples by mass spectrometry requires separation of major actinides and rare earth fission products. An HPLC method is developed for the separation of uranium, plutonium and REEs from the dissolved solution of spent U3Si2 fuel sample. The task was challenging due to the presence of aluminum and uranium in large proportions. The established ion interaction chromatography-based method was found unsuccessful to overcome the interference caused by aluminum matrix. Extraction chromatography using reversed phase stationary phase modified with HDEHP and TODGA was explored for the separation problem. Good separation among aluminum, REEs, U and plutonium was achieved using a column modified with TODGA. The optimized method exhibited good tolerance to large proportions of aluminum, uranium and nitrate salt present in the dissolved fuel solution.