The Chemistry of Containment

The safe containment of radioactive waste, particularly highly soluble isotopes like cesium-137, poses a significant and ongoing environmental challenge. Traditional cement-based matrices often struggle to efficiently immobilize cesium due to its tendency to dissolve and leach into surrounding environments. This presentation explores the use of geopolymers—robust, inorganic aluminosilicate materials—as a highly effective alternative for permanently trapping radioactive cesium and securing it from the ecosyste

By carefully tailoring the chemical formulation of these low-silica geopolymers, we can successfully induce the formation of highly stable, cesium-binding crystalline structures, such as Zeolite F and pollucite. Remarkably, the formation of pollucite—a naturally occurring mineral recognized as an optimal host for long-term cesium immobilization—can be achieved within these geopolymers at near-ambient temperatures, bypassing the extreme heat  or pressurized hydrothermal conditions conventionally required. Rigorous leaching experiments confirm that these engineered matrices selectively and efficiently retain cesium, proving their long-term viability for environmental protection

To confirm the safety and stability of these waste traps, we employ advanced analytical techniques, primarily X-ray Powder Diffraction (XRD) and Solid-State Nuclear Magnetic Resonance (NMR) spectroscopy. By applying newly developed enhancements to multiple-quantum NMR methodologies, we significantly increase the sensitivity and resolution of our measurements. These advanced molecular tools allow us to "see" exactly where the cesium is locked within the complex matrix at the atomic level. Ultimately, these atomic-level insights bridge the gap between microscopic chemical analysis and macro-scale environmental safety, guiding the design of superior, reliable nuclear waste retention materials

:About me

Amir Goldbourt. BSc Tel Aviv University in Chemistry and computer science. PhD in Chemical Physics, Weizmann Institute of Science (supervisor Shimon Vega) 2003. Postdoc biomolecular NMR, Columbia University (supervisor Ann E McDermott) 2007. Joined Tel Aviv University, school of chemistry, in 2007. Full professor since 2019. Holds the Nathan Cummings Chair for Natural Products in Medicine Chair since 2025. Affiliated with the new school of Environmental sciences since 2025. Chair, Department of Physical Chemistry 2023-26. Main research: Solid-state NMR-based structural chemistry, biology and virology