Separation of Americium from Plutonium-Solvent Extraction Raffinate and Conversion to Americium Oxide

Abstract

  A one-step simple extraction chromatography method using a TODGA (N,N,N′,N′-tetraoctyl-diglycolamide) adsorbent column has been developed to separate the americium from plutonium-solvent extraction raffinate. The raffinate contained Am (~620 mg/l), Np (~107 mg/l), Ag (~2000 mg/l), Fe (~290 mg/l), Cr (~38 mg/l), Ni (~52 mg/l) and a trace amount of TBP. Small- scale and scale-up tests for the separation of americium and conversion to americium oxide were carried out in NUCEF. Efforts were made to increase the yield and purity of americium. The americium was separated with 83-92% yields and 97-98% purities by small-scale tests and 85-95% yields and 98-99% purities by scale-up tests. The yields for the conversion of americium nitrate solution to americium oxide were 89-100% by small-scale tests and 85-96 % by scale-up tests. Approximately 1.8 grams of americium oxide was recovered from 6 litres of the raffinate and supplied for the research on the high-temperature chemistry of TRU.