By John Stang
Most viable options for cleaning up highly radioactive liquid waste at the Hanford Site in Washington involve abandoning a partly-built plant that cost billions of dollars, according to a recent Department of Energy analysis.
Of 11 viable cleanup options DOE studied in an analysis of alternatives dated Jan. 12, only two include the partially completed waste pretreatment plant the agency put on hold in 2012, after a site whistleblower’s safety concerns prompted an intervention from the secretary of energy. DOE had not committed to any one of the 11 options as of Thursday.
According to a 2018 estimate from the Army Corps of Engineers, DOE had spent about $11 billion overall on Hanford’s Waste Treatment and Immobilization Plant through 2018, including $3.8 billion or so on the pretreatment plant that was supposed to separate high-level waste from less radioactive low-level waste.
It would cost roughly another $8 billion to finish work on the pretreatment plant, according to a DOE estimate quoted by the Government Accountability Office in 2022. Bechtel National was building the pretreatment plant under contract to DOE from 2002 to 2012 and the agency has paid to keep the facility in stasis since then.
The plant as conceived was a key cog in DOE’s plan to turn Hanford’s radioactive waste, left over from decades of plutonium production for nuclear weapons and in places leaking from storage tanks, into stable glass cylinders. The agency has a legal deadline to start solidifying the site’s lower-level radioactive waste in 2025.
Between 5 million and 6 million gallons of the liquids and sludge in Hanford’s 177 underground tanks are high-level radioactive wastes. Those are mixed together with roughly 50 million gallons of low-activity wastes. The pretreatment plant was supposed to sort the high-level waste from the low-level waste.
If the pretreatment plant is out of the picture, DOE could separate wastes by building equipment and facilities detailed in nine of the options studied in the Jan. 12 analysis of alternatives. These could include a new feed preparation facility and a new effluent management facility.
If DOE keeps the pretreatment plant, one option the agency analyzed calls for technical changes within the plant, pushing its estimated capital cost to $38 billion with a lifecycle cost of $151 billion. Under this scenario, high-level waste could be solidified by 2084.
The other analyzed scenario with a pretreatment plant involves altering or shrinking the facility, for a capital cost of $39.3 billion and a lifecycle cost of $123 billion. This option, however, would wrap up high-level waste treatment in 2064.
In all the high-level waste treatment scenarios DOE studied, the agency estimated that it would finish solidifying Hanford’s waste between 2062 and 2084, assuming unconstrained annual budgets. With limits set at $2.5 billion a year, the completion dates will be farther in the future.
Meanwhile, low-level wastes are being removed from the tank wastes via a Tank-Side Cesium Removal system. These will be solidified in the direct feed low activity waste portion of the waste treatment plant, which according to DOE could go online sometime between December 2023 and mid-2025.
A second low-activity waste plant will eventually be needed, at a time yet to be determined, unless DOE and other stakeholders decide on some alternative means of cleaning up low-level waste.
The Washington Department of Ecology and DOE have been in closed-door talks on numerous Hanford clean-up matters for three years, with both sides silent on what is being negotiated. Last August, U.S. Energy Secretary Jennifer Granholm said the results of those talks will determine how much money DOE will request annually for the glassification project.
