Elemental groups separation for high-level waste partitioning using a novel silica-based CMPO extraction-resin

Hoshi, Harutaka*; Wei, Y.*; Kumagai, Mikio*; Asakura, Toshihide; Uchiyama, Gunzo* 

To facilitate the management of high-level liquid waste (HLLW) and minimize its long-term radiological risk in geologic disposal, we have proposed an advanced partitioning process by extraction chromatography using a minimal organic solvent and compact equipment to separate long-lived minor actinides (MA) and specific fission products (FP) such as Zr and Mo from nitrate acidic HLLW solution. Novel silica-based extraction-resin for elemental groups separation was prepared by impregnating CMPO (octyl(phenyl)-N, N-diisobutylcarbamoylmethylphosphine oxide) into a macro-reticular styrene-divinylbenzene copolymer immobilized in porous silica particles with a diameter of 50 m (SiO-P). Separation experiments for simulated HLLW solutions containing a trace amount of Am (III) and macro amounts of typical FP elements were carried out by column chromatography. It was found that the elements in the simulated HLLW were successfully separated to the following three groups: Cs-Sr-Rh-Ru, Pd-Ln-Am and Zr-Mo.