Ion exchange removal of cesium from Hanford tank waste supernates with SuperLig® 644 resin

SuperLig(R) 644 ion exchange resin is currently being evaluated for cesium (Cs-137) removal from radioactive Hanford tank waste supernates as part of the River Protection Project. Testing was performed with actual Hanford tank wastes of widely different compositions using two identical ion exchange columns connected in series each containing approximately 5.5- 6.5 ml of SuperLig(R) 644 resin. The ion exchange columns utilized the same resin material that was eluted between the column tests. This was done to demonstrate the performance of the SuperLig(R) 644 resin for cesium removal from waste samples of different compositions, determine the loading and elution profiles, and to validate design assumptions for full- scale column performances. Decontaminated product solutions generated at the same operating temperature and constant residence times (bed volumes per hour) exhibited the same chemical compositions as their feed samples. The compositions of eluate solutions were generally as expected with the exception of uranium and total organic carbon, which where concentrated by the resin. Development of a pretreatment method for the SuperLig(R) 644 resin has been critical to successful column operation with different waste solutions.