Millions of gallons of high-level radioactive waste are contained in underground tanks at U.S. Department of Energy sites such as Hanford and Savannah River. Most of the radioactivity is due to 137Cs and 90Sr, which must be extracted in order to concentrate the waste. An ion exchanger, crystalline silicotitanate IONSIV IE911, is being considered for separation for Cs at the Savannah River Site (SRS). While the performance of this ion exchanger has been well characterized under normal operating conditions, Cs removal at slightly elevated temperatures, such as those that may occur in a process upset, is not clear. Our recent study indicates that during exposure to SRS simulant at 55 degrees Celcius and 80 degrees Celcius, an aluminosilicate coating formed on the exchanger surface. There was concern that the coating would affect its ion exchange properties. A LEO 982 field emission scanning electron microscope (FESEM) and an Oxford ISIS energy dispersive x-ray spectrometer (EDS) were used to characterize the coating.
Revised: May 3, 2004 |
Published: October 30, 2001
Citation
Young J.S., Y. Su, L. Li, and M. Balmer. 2001.Characterization of Aluminosilicate Formation on the Surface of a Crystalline Silicotitanate Ion Exchanger. In Microscopy and Microanalysis 2001 : Proceedings ; Microscopy Society of America 59th Annual meeting, - Microbeam Analysis Society 35th Annual Meeting, Long Beach, California, August 5 - 9, 2001, edited by G W Bailey, 7, 498-499. New York, New York:Springer. PNNL-SA-34158-A.