Professor Goel has been awarded a $1,500,000 grant by the U.S. Department of Energy – Office of River Protection to study the factors affecting the design and development of glasses formulated for direct-feed vitrification of Hanford’s low activity waste and high-level waste.
The Hanford site in Washington State is a home to ~56 million gallons of highly complex radioactive waste stored in 177 underground steel tanks. The U.S. Department of Energy (DOE) is building a Tank Waste Treatment and Immobilization Plant (WTP) at Hanford site to separately vitrify low activity waste (LAW) and high level waste (HLW) in borosilicate glass at 1150 °C using Joule-heated ceramic melters. In order to begin the treatment of the nuclear waste as soon as possible, the U.S. DOE is considering the possibility of implementing a sequenced approach for vitrification of this waste, known as direct feed LAW (DFLAW) and direct feed HLW (DFHLW). If brought into practice, this approach will begin the treatment of LAW by 2022. The implementation of the direct feed option is likely to affect the glass formulations and waste loadings and have effect on the downstream vitrification operations. In particular, the two major challenges during vitrification of DFLAW and DFHLW are expected to be (1) high concentration of alkali/alkaline-earth sulfates, phosphates and chromates in waste melter feeds which will lead to salt formation on the melt surface, thus leading to several potential problems associated with melter operation, and (2) corrosion of K-3 refractory in the melter due to high alkali and alkaline-earth content in the waste feed leading to reduction in the melter lifetime. The project is focused on understanding and elucidating the compositional, structural, and thermo-kinetic drivers governing the above-discussed problems. This will allow the US DOE to optimize the glass compositions in order to achieve higher waste loadings while enhancing the melter lifetime.
Several undergraduate, graduate students and postdoctoral researchers will be trained in the framework of this project.