CESIUM-REMOVAL FLOW STUDIES USING ION-EXCHANGE

The development, selection, and implementation of technologies to be u sed in removing cesium from radioactive liquid wastes in preparation f or their final disposition is discussed. The methodology involved test ing several proposed sorbents in ion-exchange columns using actual liq uid wastes from underground storage tanks at U.S. Department of Energy sites. The sorbents initially tested included resorcinol-formaldehyde resin (RF), CS-100 resin, SuperLig 644C resin, 3M WEB with embedded S uperLig 644, granular potassium cobalt hexacyanoferrate, and granular crystalline silicotitanates (CSTs). The results of the bench-scale tes ting were used to select the sorbents for the full-scale Cesium Remova l Demonstration Project (CsRD). This project will treat up to 25,000 g al of radioactive supernatant stored in the Melton Valley Storage Tank s (MVSTs) at Oak Ridge National Laboratory (ORNL). The demonstration s ystem is modular in design and will process supernatant at flows up to 5 gal/min through 12-in.-diam columns. Following the demonstration th e system will be used for routine processing of tank waste at ORNL. To show their applicability to wastes at other sites, RF and CST sorbent s were tested in a bench-scale column using a diluted Hanford supernat ant liquor (double-shell slurry feed) from tank 241-AW-101. The result s are compared with those from tests of MVST supernatant.