Development of extraction chromatographic adsorbent using alkylpyridinedicarboxyamides as extractant for separation of trivalent minor actinides from lanthanides. Stability and separation ability against nitric acid exposure and gamma-ray irradiation

Toward the development of a practical separation method for trivalent actinides and lanthanides, we used extraction chromatography with alkylpyridinedicarboxyamides as the extractant. The results confirmed that the performance degradation of the adsorbent caused by contact with HNO3 and/or irradiation with gamma-rays would be very small during the operation of column chromatography. The optimal conditions for the column separation were also determined: eluent, 5 M HNO3; flow rate, 0.1 mL min-1. In addition, the change of average particle size of inert support material from 250-850 μm (XAD4) to 25-45 μm (Gelpack A040) brought about the improvement of separation between trivalent actinides and lanthanides. (author)