The immobilizing performance and mechanism of geopolymer and its derivative materials for high-level radionuclides Cs and Sr: a review

How to properly handle the high-level radionuclides cesium(Cs) and strontium(Sr) generated during the nuclear fuel cycle has become a challenging issue. Geopolymer, a novel aluminosilicate inorganic gel material, can be in-situ converted into zeolite and ceramics, exhibiting excellent immobilization capability for radioactive nuclides. This work provides a comprehensive review of the research on the conversion and synthesis methods of geopolymer into zeolite and ceramics, and conducts a detailed analysis of the performance and mechanisms of geopolymers, geopolymer-zeolite composites, and geopolymer ceramics in the immobilization of Cs and Sr. Through a thorough analysis and summary of existing literature, this study presents the optimal conditions for the conversion of geopolymers into zeolite and proposes improved methods for geopolymer ceramic immobilization of Cs. Furthermore, a comparison and analysis are conducted of the applicability, as well as the advantages and disadvantages of these three solidification matrices in immobilizing Cs and Sr. Finally, the challenges and prospects faced by geopolymer and its derivative materials in the immobilization of high-level radionuclides Cs and Sr are discussed.