The US Hanford Site Waste Treatment & Immobilisation Plant (WTP) team has poured the first batches of glass forming beads, called frit, into a melter which recently achieved its operating temperature of 2,100°F. At that temperature, the beads melt to create the first molten pool inside the melter, which during future hot operations will immobilise radioactive and chemical tank waste in a form safe for permanent disposal. Each bag of frit weighs 300 pounds. The team will pour frit in regular intervals until about 40,000 pounds have been added and the molten pool is about 31 inches deep.

The US Department of Energy’s (DOE’s) Office of Environmental Management (EM) said the accomplishment “represents another positive step toward waste treatment operations at the WTP’s Low-Activity Waste (LAW) Facility as part of EM’s Direct-Feed Low-Activity Waste Program at Hanford”.

“This is a proud time for our Hanford team as we have established a molten glass pool in our first melter,” said Hanford Site Manager Brian Vance. “It’s a tremendous success made possible through the entire team’s dedication to safely progressing our important clean-up mission.”

Two 300-tonne melters inside the LAW Facility at the WTP are the heart of the vitrification process, which will immobilise the tank waste in glass. During vitrification, treated waste will be fed to the LAW Facility’s melters. The waste mixed with frit will be poured into specially designed stainless-steel containers. The containers will then be moved a short distance to the Integrated Disposal Facility at the Hanford Site for disposal.

“Our team is excited about furthering our progress in achieving continuous melter operations,” said Brian Hartman, the WTP project director and senior vice president for Bechtel, which is designing, building and commissioning the plant for the EM Office of River Protection.

The Hanford Site is home to approximately 56m gallons of radioactive tank waste stored in 177 underground tanks, representing one of DOE’s largest environmental risks and most complex challenges. The tank waste is a result of nearly five decades of plutonium production during World War II.

Image: The first batch of frit is poured into the melter at Hanford’s LAW facility (courtesy of Bechtel)