Direct separation of minor actinides from high level liquid waste by Me 2 -CA-BTP/SiO2-P adsorbent

Abstract

Directly separating minor actinides (MA: Am, Cm, etc.) from high level liquid waste (HLLW) containing lanthanides and other fission products is of great significance for the whole nuclear fuel cycle, especially in the aspects of reducing long-term radioactivity and simplifying the post-processing separation process. Herein, a novel silica-based adsorbent Me2-CA-BTP/SiO2-P was prepared by impregnating Me2-CA-BTP (2,6-bis(5,6,7,8-tetrahydro-5,8,9,9-tetramethyl-5,8-methano-1,2,4-benzotriazin-3-yl)pyridine) into porous silica/polymer support particles (SiO2-P) under reduced pressure. It was found Me2-CA-BTP/SiO2-P exhibited good adsorption selectivity towards 241Am(III) over 152Eu(III) in a wide nitric acid range, acceptable adsorption kinetic, adequate stability against γ irradiation in 1 and 3 M HNO3 solutions, and successfully separated 241Am(III) from simulated 3 M HNO3 HLLW. In sum, considering the good overall performance of Me2-CA-BTP/SiO2-P adsorbent, it has great application potential for directly separating MA from HLLW, and is expected to establish an advanced simplified MA separation process, which is very meaningful for the development of nuclear energy.