Development of a new flowsheet for partitioning of long-lived radionuclides from high-level wastes: the “CRAMEX” process

A flowsheet for a novel CRAMEX (crown ether and amide for the extraction) process has been developed. The solvent system proposed is a combination of 0.3 M N,N,N′,N′-tetraoctyl diglycolamide (TODGA) and 0.2 M dibenzo-21-crown-7 (DB21C7) in polar fluorinated diluents that co-extracted cesium, strontium, actinides and lanthanides. The stripping of cesium and strontium from the loaded organic phase can be carried out with diluted nitric acid solutions (< 0.1  M HNO3). A mixture of 0.5 M methylamine carbonate and 10 g/l DTPA provides stripping of actinides and lanthanides.