Reuse System for Powdered Ion-Exchange Resins

A reuse system has been developed for powdered ion-exchange resins generated from nuclear power plants in order to reduce their waste volume. The system consists of

1. crud removal from resins
2. decomposition of flocks (flocculated resins)
3. resin separation into cation and anion types
4. regeneration of each type.

The most important points in this system are items 2 and 3, because generally resins flocculate too tightly to separate easily. By combined usage of a strong electrolyte (15 wt% NaOH solution) and a dual-basket-type centrifuge, spent powdered resins can be separated with an efficiency of 95% and regenerated for another use. The waste volume can be reduced to one-half after four reuse cycles, with a decrease in the ion-exchange capacity of only 5%.