10/10/2011
Photoreduction for Formation and Sequestration of Low-Valent Technetium
Summary
Technetium-99 (Tc-99) is a major fission product of uranium-235 and comprises a large component of radioactive waste. Under normal environmental conditions, it exists in its highly oxidized (VII valent) form, which is stable, very soluble, and migrates easily through the environment. If reduced, it readily oxidizes back to this stable form. This reduction-oxidation activity of Tc-99 hampers its separation from spent fuel rods and cleanup of radioactive tank waste and presents a problem in the identification of a suitable waste form. A new Tc-photoreduction study employs polyoxometalates, nanometer-sized metal oxide aggregates that precipitate the highly soluble Tc-99 allowing for its recovery and isolation. This DOE-funded project involves graduate students and postdoctoral fellows as part of an effort to develop a new cadre of radiochemists.
References
Burton-Pye, B. P., I. Radivojevic, D. McGregor, I. M. Mbomekalle, W. W. Lukens, Jr., and L. C. Francesconi. 2011. “Photoreduction of 99Tc Pertechnetate by Nanometer-Sized Metal Oxides: New Strategies for Formation and Sequestration of Low-Valent Technetium,” Journal of the American Chemical Society 133, 18802-15. DOI:10.1021/ja2060929.