A long-awaited report released Monday from the National Academies finds a “strong technical case” for using concrete-like grout to augment operation of the Waste Treatment and Immobilization Plant at the Department of Energy’s Hanford Site in Washington state.
The report from the National Academies of Sciences, Engineering, and Medicine lauded a study by DOE’s Savannah River National Laboratory in South Carolina, which like earlier drafts reviewed by the academies deemed grout a cheaper and quicker-to-deploy alternative to building a second Waste Treatment Plant to turn waste into glass logs.
Grout is also more technically proven than a steam reforming plant akin to the Integrated Waste Treatment Unit at Idaho National Laboratory. That also was the conclusion of a draft report issued in January.
But the final document also cautions that grout must still pass muster with regulators in Washington state and that the public might view grout as less desirable than turning the liquid waste stored in Hanford’s many underground tanks into glass in a process called vitrification.
The Waste Treatment Plant built by Bechtel should be able to vitrify all the high-level waste generated from decades of plutonium production at Hanford, but not the low-level waste that accounts for the bulk of the waste by volume. The vitrification is currently expected to start operating by 2025. Until the past year, DOE had been hoping to start operations by the end of 2023.
In April, the acting head of the DOE Office of Environmental Management told Congress grout could be a viable option for solidifying more than half of the 56 million gallons of liquid radioactive waste now stored underground in 177 tanks at Hanford. The report was to be discussed at a hybrid meeting scheduled for 12:00 p.m. Pacific time on June 6 at Washington State University Tri-Cities in Richland, Wash. A link to download the report itself is available here.
Earlier this month, DOE and the Washington state Department of Ecology announced a “conceptual agreement” involving tank waste cleanup and related issues at Hanford following conclusion of “holistic” talks that spanned about four years and involved the U.S. Environmental Protection Agency.
Because the talks paralleled the work by the National Academies and the Savannah River lab, the final report released Monday “was limited to purely technical considerations” and not whether it will gain Washington state regulatory approval or public acceptance, the National Academies said.
The report by the Savannah River National Laboratory with review by the National Academies was called for by Congress via the fiscal 2021 National Defense Authorization Act, according to a summary of the report. Two grout options explored in the report include grouting with disposal onsite at Hanford or grouting with disposal offsite at a location such as Waste Control Specialists in Texas.
In its latest projection, DOE has said the Hanford Site could be fully cleaned up between 2078 and 2091.
