TY - JOUR
T1 - Recent advances in immobilization of radioactive cesium and strontium-bearing wastes in alkali activated materials - A review
AU - Mukiza, Emile
AU - Phung, Quoc Tri
AU - Seetharam, Suresh
AU - Nguyen, Thi Nhan
AU - Bruggeman, Christophe
AU - De Schutter, Geert
N1 - Score=10
Publisher Copyright:
© 2024 Elsevier Ltd
PY - 2024/11/1
Y1 - 2024/11/1
N2 - This review discusses recent advances in the use of alkali-activated materials (AAMs) to host high heat and radiation-emitting cesium (Cs) and strontium (Sr) wastes. It examines the evolution of geopolymerization, mechanical properties, mineralogy, microstructure, and leaching behavior of Cs-and/or Sr-bearing AAMs, considering their chemical interaction with Cs and Sr nuclides and exposure to temperature and gamma radiation induced by Cs and Sr. The literature indicates that Cs and Sr slightly degrade the mechanical properties of AAMs, with Sr having a more pronounced effect. For AAMs with a low SiO2/Al2O3 ratio, decay heat from Cs and Sr can crystallize zeolitic phases, which are beneficial in the short term but detrimental in the long term because of their low stability against gamma radiation. Cs was immobilized via ion exchange within the aluminosilicate phase and Sr mainly by precipitation, but the immobilization of their respective daughter nuclides Ba and Zr was not demonstrated. Gamma radiation exposure does not significantly alter AAM properties, and nitrates in Cs and Sr-bearing wastes reduce gamma-induced water radiolysis. AAMs are promising hosts for Cs and Sr-bearing wastes, but further studies are needed using realistic Cs and Sr waste loading to evaluate the synergistic effects of Cs and Sr chemical behavior, decay heat, and gamma irradiation on the evolution of properties of waste forms, and the ability of AAMs to accommodate daughter nuclides Ba and Zr.
AB - This review discusses recent advances in the use of alkali-activated materials (AAMs) to host high heat and radiation-emitting cesium (Cs) and strontium (Sr) wastes. It examines the evolution of geopolymerization, mechanical properties, mineralogy, microstructure, and leaching behavior of Cs-and/or Sr-bearing AAMs, considering their chemical interaction with Cs and Sr nuclides and exposure to temperature and gamma radiation induced by Cs and Sr. The literature indicates that Cs and Sr slightly degrade the mechanical properties of AAMs, with Sr having a more pronounced effect. For AAMs with a low SiO2/Al2O3 ratio, decay heat from Cs and Sr can crystallize zeolitic phases, which are beneficial in the short term but detrimental in the long term because of their low stability against gamma radiation. Cs was immobilized via ion exchange within the aluminosilicate phase and Sr mainly by precipitation, but the immobilization of their respective daughter nuclides Ba and Zr was not demonstrated. Gamma radiation exposure does not significantly alter AAM properties, and nitrates in Cs and Sr-bearing wastes reduce gamma-induced water radiolysis. AAMs are promising hosts for Cs and Sr-bearing wastes, but further studies are needed using realistic Cs and Sr waste loading to evaluate the synergistic effects of Cs and Sr chemical behavior, decay heat, and gamma irradiation on the evolution of properties of waste forms, and the ability of AAMs to accommodate daughter nuclides Ba and Zr.
KW - Alkali activated materials
KW - Radioactive waste immobilization
KW - Cesium
KW - Strontium
UR - https://ecm.sckcen.be/OTCS/llisapi.dll/open/86722996
U2 - 10.1016/j.jenvman.2024.122746
DO - 10.1016/j.jenvman.2024.122746
M3 - Article
SN - 0301-4797
VL - 370
JO - Journal of environmental management
JF - Journal of environmental management
M1 - 122746
ER -