Patent ID: 8354085
Filing Date: 2013-01-15
Classification: C22B,G21C,Y02E,Y02W

Abstract:
1. A process for separating minor actinides from lanthanides in the reprocessing of a spent nuclear fuel comprising providing a fluid mixture comprising, a trace amount of fission products, lanthanides, minor actinides, rare earth elements, nitric acid and water; adding at least one first organic complexing agent to the fluid mixture; extracting the fluid mixture with a solvent comprising a mixture a first extractant, a second extractant and an organic diluent to form a first organic extractant stream and a first aqueous raffinate comprising fission products, performing at least a first scrubbing step on the first organic extractant stream with a mixture of dicarboxylic acid and a first chelating agent to form a first scrubber discharge; in a first stripping step, stripping the scrubber discharge with a buffer and a second chelating agent in the pH range of from about 2.5 to about 6.1 to produce an actinide and lanthanide stream and a spent organic diluent, where the first extractant is selected from the group consisting of bis(2-ethylhexyl)hydrogen phosphate (HDEHP) and mono(2-ethylhexyl)-2-ethylhexyl phosphonate (HEH(EHP)) and the second extractant is selected from the group consisting of N,N,N,N-tetra-2-ethylhexyl diglycol amide (TEHDGA) and N,N,N′,N′-tetraoctyl-3-oxapentanediamide (TODGA).