Researchers have vitrified 2 gallons of radioactive waste removed from a Hanford Site storage tank in a first-of-a-kind demonstration of the processes that will be used at the Waste Treatment Plant being built at the Energy Department facility in Washington state.
Pacific Northwest National Laboratory researchers said it was the first time Hanford tank waste has been converted to a glass form in a continuous process similar to the approach planned for the vitrification plant, rather than in batches. The test was performed for DOE and its tank farm contractor, Washington River Protection Solutions (WRPS).
“This successful test confirms the science and engineering approach,” said Will Eaton, who led the test for PNNL. Previous tests have been conducted with waste simulants or with crucibles of waste heated all at once, which does not show how well the plant’s processes will control the chemistry of the glass as waste mixtures progress from liquid to molten glass.
Waste for the test was drawn from double-shell Tank AP-105. The initial waste to be vitrified at the Waste Treatment Plant is planned to come from am AP Tank Farm tank. The Energy Department plans to start treating low-activity radioactive waste at the plant as soon as the end of 2021.
Two gallons of liquid low-activity waste were mixed with glass-forming material in a fume hood to prepare a 3-gallon mixture for vitrification. The mixture was dripped into a steel container within a furnace that heated the mixture to 2,100 degrees Fahrenheit in an adjacent fume hood. The test was conducted at PNNL’s Radiochemical Processing Laboratory in the Hanford 300 Area.
The glass produced in the test is being analyzed, with plans being made to try the test again with waste from the AP-107 tank using slightly different pretreatment methods. “Being able to run real tank waste instead of simulants through these tests provides valuable input for validating and refining our approach to the treatment of low activity waste,” said Kris Colosi, WRPS project manager.
