Pacific Northwest National Laboratory (PNNL) researchers have vitrified low-activity nuclear waste from the Hanford Site and turned them into durable glass.
The Hanford Site is a decommissioned nuclear production complex on Washington State’s Columbia River.
Around three gallons of low-activity Hanford tank waste were vitrified at PNNL’s Radiochemical Processing Laboratory this April.
The laboratory-scale demonstration is an important step toward the eventual treatment of millions of gallons of hazardous waste generated during past plutonium production at Hanford.
The researchers, in order to vitrify the material, mixed the liquid waste with glass-forming materials and pumped it, at a controlled rate, into the melter.
The melter sits inside a furnace that keeps the glass forming materials within it at 2100°F. A half-pound of glass poured from the melter every half hour, and the test produced approximately 20 pounds of glass.
“This successful test confirms the science and engineering approach,” said Will Eaton who led the test for PNNL. “Seeing actual Hanford low-activity waste being converted to glass is really exciting. It ties together 20 years of work from the design and construction of the Waste Treatment Plant to the research and testing that has supported that effort.”
PNNL’s vitrification test platform is said to mimic the key processes used in the Direct Feed Low-Activity Waste system (DFLAW) being constructed at Hanford.
DFLAW on its part will remove solids and cesium from tank waste and send the resulting low-activity waste to the Waste Treatment Plant for vitrification inside large melters.
A second laboratory-scale vitrification test is planned later this year using approximately two gallons of waste from a different Hanford tank. Pretreatment of that waste will test different filtration and ion exchange methods.
Image, content credits: PNNL, Susan Bauer