Project Title : Studies Related to Chemical Mechanisms of Gas Formation in Hanford High - Level Nuclear Wastes

Project Title : “ Studies Related to Chemical Mechanisms of Gas Formation in Hanford High - Level Wastes ” ( Award No . DE - FG 07 - 96 ER 14690 )

Thermal and Radiolytic Gas Generation in Hanford High-level Waste

Mixed radioactive and chemical wastes stored in tanks across the DOE complex generate hydrogen, ammonia, nitrous oxide, and nitrogen by a complex series of radiolytic and thermolytic reactions. Flammable conditions may result when these gases accumulate in the dome space of the waste tanks. A phenomenological model was developed that successfully predicts gas generation rates for many of Hanfor...

“Foaming and Antifoaming in Radioactive Waste Pretreatment and Immobilization”

The objective of this research is to develop a fundamental understanding of the physico-chemical mechanisms that cause foaminess in the DOE High Level (HLW) and Low Activity radioactive waste separation processes and to develop and test advanced antifoam/defoaming agents. Antifoams developed for this research will be tested using simulated defense HLW radioactive wastes obtained from the Hanfor...

Dynamic Effects of Tank Waste Aging on Radionuclide-Complexant Interactions

The overall objective of this project is to provide a scientific basis for safely processing complexant-containing high-level tank wastes for disposal. Our key goals are to identify methods for preparing realistic complexant-containing tank waste simulants, and to use those simulants to determine the relative importance of organic complexants and their breakdown products on the partitioning of ...

Behavior of technetium in nuclear waste vitrification processes

Nearly 100 tests were performed with prototypical melters and off-gas system components to investigate the extents to which technetium is incorporated into the glass melt, partitioned to the off-gas stream, and captured by the off-gas treatment system components during waste vitrification. The tests employed several simulants, spiked with 99mTc and Re (a potential surrogate), of the low activit...