nuclear-news

Researchers in Richland have done what the $17 billion vitrification plant at Hanford is intended to do — turn radioactive waste into a solid glass form.

Over about 24 hours last month researchers ran a laboratory-sized plant, dripping a radioactive waste mixture into a miniature melter inside the Pacific Northwest National Laboratory’s Radiochemical Processing Laboratory.

When they were done, they had 20 pounds of glass encasing actual Hanford waste.

……….The vitrification plant — or Waste Treatment Plant — at the Hanford nuclear reservation has been under construction since 2002, with a court-ordered deadline of 2023 to start treating some of the 56 million gallons of radioactive waste in underground tanks.

Much of the waste, which is left from the past production of plutonium for the nation’s nuclear weapons program, is planned to be vitrified, or turned into a solid glass form for disposal.

In the past about a cup of waste at a time has been vitrified — but not in a way that really mimics the system to be used at the plant.

Scientists have not been able to determine in earlier tests how the plant’s process would control the chemistry of the mixture, which determines how well waste is contained within the mixture as vitrification progresses from liquid waste to molten glass.

“This is the first time low-activity Hanford tank waste has been vitrified in a continuous process, very similar to the treatment process that will be used at Hanford, rather than as a single batch,” said Albert Kruger, a Hanford Department of Energy glass scientist.

Results of the demonstration will be used to help DOE and its tank farm contractor, Washington River Protection Solutions, make plans for operating the vitrification plant. They commissioned the tests from PNNL, an expert in the vitrification field.

…… At Hanford, DOE’s plan is to separate some low-activity radioactive waste from the site’s underground tanks, leaving high-level radioactive waste for later treatment at the vitrification plant……… Low activity radioactive waste is primarily liquid, but solids and radioactive cesium in the liquids are designated as high level radioactive waste and must be removed if the waste is treated as low activity waste…….http://www.tri-cityherald.com/news/local/hanford/article211071854.html