The Department of Energy considers 2,000 gallons of tank waste earmarked for the test-bed initiative at the Hanford Site in Washington state to be low-level radioactive waste and not high-level waste, the agency wrote in a Federal Register notice published this week.
The notice, officially the final Waste Incidental to Reprocessing Determination, which is now available, is posted online. The test-bed initiative is an experiment to see if DOE can solidify low-activity liquid waste leftover from Cold War plutonium production by suspending it in cement-like grout instead of solidifying it in a glass-like substance.
Earlier plans called for this 2,000-gallon demonstration to potentially set the stage for a larger test with 500,000 gallons, DOE has said.
On Monday, DOE said it is taking a go-slow approach to grouting.
“Should the TBI [test bed initiative] demonstration be completed successfully, the department will evaluate the results and benefits of further implementation of the technology,” a DOE spokesperson said in an emailed response to Exchange Monitor Monday afternoon. Any larger-scale test waste would be evaluated in a National Environmental Policy Act review, DOE said.
DOE prepared the final evaluation “after carefully considering comments received” from the Nuclear Regulatory Commission, states, tribal nations, stakeholders and the public, and after doing revisions of analyses and technical papers, DOE said.
Under the test-bed project, the waste would be pretreated at Hanford to remove key radionuclides, then grouted into a solid form at an offsite commercial facility and disposed of at a licensed mixed low-level radioactive waste disposal site outside the state, according to the notice.
Six years ago in 2017, DOE did a pilot test with three gallons of liquid, low-activity waste treated at Hanford’s 222-S Laboratory. It was grouted at the local Perma-Fix Environmental Services Northwest plant near Richland, Wash., and sent to Waste Control Specialists in Andrews, County, Texas for final disposal.
Federal researchers have been looking into grout as an option for low-level waste that cannot be accommodated at the new Waste Treatment and Immobilization Plant at Hanford. DOE now expects to start up the plant by 2025.
The facility will mix tank waste with glass and create stable, log-like cylinders. DOE already uses this method, known as vitrification, at the Savannah River Site’s Defense Waste Processing Facility. Savannah River was another Cold War-era plutonium plant.
At the urging of federal reports, done by the National Academies of Science, the Savannah River National Laboratory and other entities, DOE is exploring grout as a means of solidifying the supplemental low-level waste.
Once the Washington state Department of Ecology issues a research, development and demonstration permit, field work to install and operate the equipment could be finished within six months, DOE said in an email Monday.
About $10 million in fiscal year 2020 funds are available for the proposed 2,000-gallon test-bed demonstration to install the equipment and perform the 2,000-gallon test. Another $7 million in fiscal year 2022 funds would be tapped to remove and dispose of the equipment, according to a fact sheet shared by a DOE spokesperson.
Waste for the demonstration will come from Hanford’s Tank SY-101, chosen for the test-bed demonstration because it is not currently associated the vitrification plant’s Direct-Feed-Low-Activity Waste facility operations, according to the DOE fact sheet.
A three-page roundup of the test-best demonstration is posted online by Washington state Ecology and is available here.
