Cesium Ion Exchange Program at the Hanford River Protection Project Waste Treatment Plant

The Hanford Waste Treatment and Immobilization Plant (WTP) will use cesium ion exchange to remove Cs-137 from Low Activity Waste (LAW) down to a maximum activity of 0.3 Ci/m3 in the Immobilized LAW (ILAW) product. The WTP Project baseline for cesium ion exchange is the elutable SuperLig(R) 644 (SL-644) resin (registered trademark of IBC Advanced Technologies, Inc., American Fork, UT) or a U. S. Department of Energy (DOE) approved equivalent. SL-644 is solely available through IBC Advanced Technologies. The WTP Project is conducting a three-stage process for selecting and qualifying an alternative ion exchange resin. Resorcinol formaldehyde (RF) is being pursued as a potential alternative to SL-644, to provide a backup resin supply. Resin cost relative to SL-644 is a primary driver. Phase I of the testing plan examined the viability of RF resin and recommended that a spherical form of RF resin be examined further. Phases II and III, now underway, include batch testing to determine the isotherm of this resin, kinetics to address the impacts of bead diameter and high sodium feed levels on processing Hanford waste with the resin, and multicycle column testing to determine how temperature and chemical cycling affects waste processing. Phases II and III also examine resin performance against simulated WTP feeds, radiolytic and thermal stability, and scale-up to pilot scale performance. We will discuss early results obtained from Phase II testing here