Technology International Incorporated 0f Virginia
US Deaprtment of Energy

A Compact Electrodialysis-Freezing, Low-Level Radioactive Waste Volume Reduction System for Nuclear Power Plants

CUSTOMER:  U.S. Department of Energy, German Town, MD

CONTRACT #: DE-AC05-84ER80199

STARTING DATE: September 1984  

DURATION: 6 months

AMOUNT: $50,000




Abdul-Fattah, Abdul-Rahman F. (1987). In-plant treatment of low-level radwaste by electrodialysis.  ATOMKERNENERGIE, 50, 188-192.

Husseiny, Abdo A. (1986, March).  A Compact Electrodialysis- Freezing, Low-Level Radioactive Waste Volume Reduction System for Nuclear Power Plants.  U.S. Department of Energy Contract # DE-ACO5-84ER8Ol99, Rep # DE/ER/8O199-l, Volumes 1 through 7, TII Rep # TILA-7O85O23-II, LaPlace, LA.


Husseiny, Abdo A. (1991, October, 8). Method of compacting low-level radioactive waste utilizing freezing and electrodialyzing concentration process. Patent #5,055,237; Technology International Incorporated; LaPlace, LA.


Present in-situ low-level liquid radioactive waste processing techniques involve the production of secondary streams; such as spent resins and evaporator bottoms.  Processing temperatures also contribute to the gaseous streams.  To minimize the secondary streams waste, the innovative system; examined in here, can be employed as a retrofit or as a replacement of existing liquid waste streams.  The electrodialysis and freezing processes do not add to the waste burden.  In addition, high concentration (high recovery) of the radioactive elements (pure water) lead to a high volume reduction of the waste from the plant.  The processes can also handle volatile elements to reduce the gas waste.

In order to examine the feasibility of the new system a conceptual design is made to process a typical inorganic waste stream from a pressurized water reactor (PWR).  Data from Waterford-3 nuclear power plant was used.  A high decontamination factor (DF) as well as high volume reduction (VR) can be achieved in comparison to currently employed systems.  However, there is an optimal point at which a tradeoff has to be made between the DF and the VR values.

The arrangement of the freezing and ED units is also considered.  For this specific stream a freezing process followed by ED treatment is preferred.  However, this arrangement has to be verified experimentally.

The new system is appropriate for processing low purity waste (high conductivity) streams and chemical waste streams.  A freezing unit can be used to treat the high purity (low conductivity) waste streams.  However, conventional methods will also suffice.  A freezing unit may also be used to process laundry and floor drain wastes whenever needed.  The new system is appropriate for boiling water reactors (BWRs) for all streams of liquid waste.  The system is expected to meet utility requirements.  Also, the system can operate well within regulatory limits.  Detailed plans are made for a pilot experiment.  The cost of the experiment is expected to be in the $500,000 range.

Patent Summary

A volume reduction process comprises combinations of a freezing eutectic, bulk, indirect crystallization process and a radwaste electrodialysis process. When employed as a liquid radioactive waste management system (LWMS) for light water reactors (LWR's), this process is designed to process liquid low-level radioactive waste (LLW) and to handle the radioactive influent in nuclear power plants (NPPs) prior to release to the environment and disposal of the radioactive material present in the waste streams.