After initial runs using a mix of radiological waste and nonradioactive simulant, the Integrated Waste Treatment Unit (IWTU) at the Idaho National Laboratory site has progressed to treating sodium-bearing waste entirely, the Department of Energy’s Office of Environmental Management (DOE-EM) announced on May 22.
At the time, DOE-EM said the IWTU had converted more than 14,700 gallons of Idaho’s 900,000 gallons of tank waste to a more stable, granular solid. Crews filled 47 stainless-steel canisters with waste and safely stored them in the IWTU’s concrete storage vaults.
The liquid waste was generated during decontamination activities following spent nuclear fuel reprocessing runs at the Idaho Nuclear Technology and Engineering Center, an activity that ended at the INL site in 1992.
Ramping up: When the IWTU began radiological operations last month, it began treating a blend that was 10 percent sodium-bearing waste and 90 percent nonradioactive simulated waste, or simulant. DOE-EM then increased the treatment blend to 50 percent waste and 50 percent simulant before progressing to 100 percent sodium-bearing waste based on the plant’s operating conditions.
Advancing to 100 percent sodium-bearing waste treatment marks a milestone for the INL site cleanup program, DOE-EM said.
Next steps: In June, IWTU crews will begin a system performance test to demonstrate compliance with established performance standards and determine adequate operating conditions under the facility’s permit.
According to DOE-EM, the INL site continues to work closely with the Idaho Department of Environmental Quality to ensure compliance during the initial stages of radiological operations, including that department’s on-site presence during the performance of the upcoming test.