講演情報

[2H12]Immobilization of Radionuclides in Fly-ash/Slag-based Geopolymer Matrices

*Mael VIAUD1, Kanako Toda1, Takumi Saito 1 (1. UTokyo)

キーワード:

Geopolymer、Radionuclide、Ion Immobilization、Fly-ash、Slag

The 2011 Fukushima Daiichi accident caused significant soil and forest contamination, necessitating innovative waste management solutions. Incineration is widely used to reduce waste volume, but it generates contaminated ash and slag, posing handling and disposal challenges. This study investigates fly ash and slag-based geopolymers as a sustainable, eco-friendly method for immobilizing radionuclides, focusing on cesium, a major uranium fission product, and selenium, which has a long half-life, diverse oxidation states, and high mobility in soil and aqueous systems, presenting environmental issues. The feasibility of forming the matrix was studied through UCS tests, while ion immobilization was assessed by leaching tests. Characterization was performed using XRD and SEM. The results show that such matrices can be formed, with notable differences in curing time, activator ratios, and practical feasibility between fly ash and slag. The matrices effectively immobilize cesium, but modifications are needed to achieve selenium immobilization.