Development of the MAREC Process for HLLW Partitioning Using a Novel Silica-Based CMPO Extraction Resin

Abstract

A new partitioning technology named “MAREC” process has been proposed for the separation of minor actinides (MA=Am, Cm) from high level liquid waste (HLLW) by extraction chromatography using a novel porous silica-based CMPO extraction resin. Separation experiments for simulated HLLW solutions containing typical fission product (FP) elements were carried out by a column packed with the CMPO/SiO₂-P extraction resin. The experimental results showed that MA as a mixture with some heavy rare earths can be effectively separated from other FP elements by using two chromatographic columns. Furthermore, some specific FP elements such as Pd, Zr and Mo were also efficiently separated from the simulated HLLW. The separation behavior of the elements are considered to result from the difference of their adsorption and elution selectivity based on the complex formation with CMPO and the eluents such as DTPA and H₂C₂O₄. These results revealed that the proposed MAREC process for HLLW partitioning is essentially feasible.

KEYWORDS:

• high level liquid waste
• minor actinide
• lanthanide
• partitioning
• extraction chromatography
• silica-based CMPO extraction resin
• DTPA
• oxalic acid