Scaled Performance of Cesium Ion Exchange with Crystalline Silicotitanate on Hanford Tank Waste - 23172

Crystalline silicotitanate (CST) ion exchanger is currently used to remove cesium (¹³⁷Cs) from the aqueous phase of Hanford tank wastes at the Tank Side Cesium Removal (TSCR) system. In preparation for full-scale TSCR operations, Pacific Northwest National Laboratory conducted laboratory-scale ion exchange column tests with waste from Hanford tank AP-107 to assess Cs load performance behavior. Column testing conducted at the small scale (2.5% full TSCR column height) was compared to current full-height TSCR performance with AP-107 waste to verify the validity of laboratory-scale tests to reflect full-height column performance. An adjustment in CST particle size was essential in scaling the column dynamics down from full scale to small scale. Impacts of temperature and Na concentration were determined based on overall mass transfer between the two column scales. (authors)