Development of a selective americium separation process using TPAEN as a water-soluble stripping agent

Abstract : Recycling americium from spent fuels is an important option considered for the future nuclear cycle. The PUREX solvent extraction process can be used to separate U and Pu from a dissolution solution of spent fuel in nitric acid. Then in a second step americium should be separated from fission products and especially lanthanides but also from curium. For this purpose, a new liquid-liquid extraction process is under development using TODGA as an extractant in the organic phase and TPAEN as a selective Am stripping agent in the aqueous phase. With this promising system it is possible to co-extract Am, Cm and lanthanides at high acidity and then selectively strip americium from the loaded organic phase at pH around 1 with TPAEN. Batch data were acquired to evaluate best conditions to develop a liquid-liquid extraction flowsheet and the effect of several parameters on Am/Cm was evaluated like concentration of ligand, cations, temperature, etc.