SEPARATION OF Am FROM Cm AND Pr IN AMMONIA AND AMMONIUM CARBONATE MEDIA

New approaches to the selective isolation of Am from the actinide–lanthanide fraction of high-level wastes with preliminary oxidation of Am to Am and Am using ammonia and ammonia–carbonate media are proposed. It was found that, when ammonium hydroxide is added to a 0.1 M HNO solution containing Am, Cm and Pr (as a mimic of the behavior of lanthanides) to pH ~8, AmO shows increased stability and is retained in solution up to 80%, and Cm and Pr in the form of poorly soluble compounds precipitate. It was also found that, in ammonia–carbonate solutions at pH ~10, up to 96% of the initial amount of Am is retained in the solution, and Cm and Pr precipitate to 85%.