Crews at the Department of Energy’s Hanford Site, near Richland, Wash., have begun heating up the first of two 300-ton melters that will be used to vitrify mixed low-level radioactive and chemical tank waste. According to the DOE’s Office of Environmental Management (EM), initiating and completing the heating of the melter is a critical step to commissioning Hanford’s Waste Treatment and Immobilization Plant (WTP), which will treat and stabilize the site’s 56 million gallons of tank waste by immobilizing it in glass through the vitrification process.
The DOE said it could take several weeks to finish heating up the melter to its commissioning and operational temperature of 2,100 degrees Fahrenheit. According to the Hanford Site’s five-year plan, released last week, the DOE intends to complete heating of the two melters early next year and begin hot commissioning of the WTP’s Low-Activity Waste Facility, where the melters are located, as early as December 2023.
The process: Bechtel National, the DOE’s prime contractor building and commissioning the WTP, is following a comprehensive process to ensure the temperature increases slowly and insulation inside the melter dries out slowly. Temporary startup heaters have been inserted into the top of the melter, and glass beads—called frit—will be added. As the beads melt and a molten glass pool rises to cover electrodes inside the melter, the melter’s permanent heating equipment will take over to maintain the operational temperature.
The process can be viewed in this 3D animation.
After heating up, the first melter will remain active using nonradioactive materials, and lessons learned from the first melter will be used to begin the process to heat up and commission the second. When both melters are at operating temperature, the facility will run simulated waste through them as they continue preparations to vitrify waste.
He said it: “Over the last two years, the department and its One Hanford contractors have made significant progress in the Direct-Feed Low-Activity Waste (DFLAW) program to prepare for treating tank waste,” said Brian Vance, manager of EM’s Office of River Protection and Richland Operations Office. “We are building on this progress by beginning to heat up the first WTP melter using a disciplined approach.”
The DFLAW program is the DOE’s sequenced approach to treating Hanford’s low-activity waste first by sending pretreated LLW directly from the site’s tank farms to the Low-Activity Waste Facility.