|Caesium partitioning: the calixarene-crowns|
The calixarene-crowns, molecules developed particularly at CEA, have a particular affinity for caesium. Caesium partitioning is carried out after the partitioning of the actinides and lanthanides in the DIAMEX process. Caesium-137, which accounts for 44% of the caesium in spent fuel, makes a major contribution to the heat released by the waste to be buried, but after 300 years has disappeared. Extracting the caesium from this radioactive waste and conditioning it separately would reduce the size and cost of deep geological disposal facilities.