[2H08-12] セメント・ジオポリマー

15:15 〜 15:30

[2H10] Enhancing Radionuclide Immobilization and Neutron Capture Potential in Metakaolin-Based Geopolymers through Boron Incorporation

XIAOBO NIU¹, *Yogarajah ELAKNESWARAN¹, Ang Li¹ (1. Hokkaido University)

キーワード：

Metakaolin-based geopolymer、Boron、Alkali-activation、Acid-activation、Radionuclides、Immobilisation

Metakaolin-based geopolymers are promising materials for radioactive waste disposal due to their ability to immobilise radionuclides. However, their limited neutron shielding capacity restricts broader applications. This study explores incorporating boron (B), a neutron-capturing element, into metakaolin-based geopolymers to enhance neutron shielding while maintaining radionuclide immobilisation. Geopolymers synthesised via alkali and acid activation were systematically studied under varied curing conditions. Analytical techniques, including XRD, SEM, NMR, FTIR, and ICP-OES, revealed that high-temperature curing enhanced B incorporation into the geopolymer framework, reducing leaching. Acid-activated geopolymers demonstrated superior structural integration of B, forming stable BO₄ structures. B increased Cs⁺ immobilisation via densification but had negligible impact on SeO₃^2- immobilisation. These findings provide insights into B-containing geopolymer design, supporting safe radioactive waste disposal in neutron-rich environments.