The U.S. Department of Energy wants negotiations to start soon with Washington state and the Environmental Protection Agency over updated plans for radioactive waste stored in 177 underground tanks at the Hanford Site in Washington state.

At the same time, the Energy Department said in a July 11 letter to Washington state Department of Ecology Nuclear Waste Program Manager Alex Smith that some of the updated milestones sought recently by the state are unrealistic.

In particular, the federal agency said the state’s desire to have a plan ready by October 2023 to move liquid waste from 149 single-shell tanks to double-shell tanks at Hanford would force DOE to adopt an approach before it digests the results of an ongoing alternatives analysis.

“There are several technical solutions to storing mixed waste and to staging and characterizing it for treatment,” Brian Vance, who manages both DOE offices at Hanford, wrote to Smith.

Vance was responding to a June 27 document from Smith, who indicated the state wants to expedite tank-waste deadlines under the Tri-Party Agreement. The 1989 agreement, between the state, DOE, and EPA, defines and prioritizes remediation programs for the former plutonium production complex. In the 1980s, it was assumed waste retrieval from single-shell tanks would start in 2018, but the deadline was delayed until 2040, Ecology Tri-Party coordinator John Price said by telephone Monday.

Roughly 56 million gallons of radioactive and contaminated liquid waste are held in underground tanks at Hanford, left by decades of plutonium production. Starting by 2023, Bechtel’s $17 billion Waste Treatment Plant will convert much of that waste into a stable glass-like substance for disposal. But the vitrification plant is designed to treat less than half of the Hanford low-activity waste, which represents about 90% of the total stockpile.

In June, Smith called upon the Energy Department to start making plans to build new tanks compliant with the Resource Conservation and Recovery Act. The federal agency has to date built 28 double-shell tanks to take waste from the old single-shell tanks. One of the 28 double-shell tanks is out of service. The 27 remaining in service “are nearly full after considering space reserved for emergencies,” Smith wrote.

This situation limits future margin for error in the event additional double-shells go out of service, or are used for pretreatment capacity at the vit plant, Smith wrote. With perhaps a third of existing tanks having experienced leaks, the state is pursuing new tanks as a buffer against further deadline slippage by DOE for moving waste into double-shell tanks.

The state is seeking interim deadlines asking almost a third of the design work for new tanks be submitted by September 2021 and about two-thirds filed a year later.

The Energy Department has historically resisted investing in new tanks, saying the funds could be put to better use on longer-term preparation for waste disposal. The federal agency will, however, submit a report to the state in June 2020 about alternate methods from removing liquids from single-shell tanks.

The Energy Department also disagrees with a state milestone for construction of interim surface barriers at all five tank farms at Hanford, although it is willing to discuss the issue in upcoming talks. Two barriers are in place now. The state wants the design plans for the first new surface barrier by late 2023.

The chief DOE objection is that the barriers, meant to prevent potentially contaminated rainfall and snowmelt around the tanks from getting into the soil, were not discussed in long-term planning last year, Price said. Other than saying the barriers can be discussed in the upcoming talks, DOE did not articulate its specific concerns.

The Energy Department said it and Ecology have common ground on issues including steps to ensure pretreatment of waste to allow direct feed low-activity waste processing at the vitrification plant and construction of the Effluent Management Facility for the Waste Treatment Plant. The latter facility is where water will be sent for evaporation during the vitrification process.

Officials hope the upcoming talks will get the state, DOE, and EPA on the same page for updated timelines for Hanford remediation.

The talks should start as soon as possible given the Energy Department’s intent to issue new contracts for Central Plateau Cleanup and tank closure this year, Vance added. The last EM procurement schedule released in May, said both contracts could be issued by the end of August.

The latest exchange between the state and federal agencies followed a May 29 letter from Ecology Director Maia Bellon to Anne Marie White, who was since resigned as the head of DOE’s Office of Environmental Management.

In the May letter, Bellon sought a “frank discussion” on the underground tank situation at Hanford. The Ecology director expressed frustration, saying DOE was not making satisfactory progress on commitments made under the Tri-Party Agreement and a 2010 federal court consent decree updating timelines for operation of the vitrification plant and retiring single-shell tanks.

Vance wants the Hanford Test Bed Initiative (TBI) included in upcoming talks. While the Energy Department withdrew the permit application for TBI in light of Ecology’s recent call for the overall Hanford negotiations, the federal agency still considers the project a priority. The test bed project “could lead to treatment and offsite disposal” of tank waste before the WTP comes online, Vance said.

The TBI would treat some of Hanford’s low-activity waste by turning it into a grout-like substance rather than sending it through the Waste Treatment Plant for vitrification. The technology has been tested on a 3-gallon sample of Hanford waste.

In January, DOE issued a $4.8 million contract to the Aerostar Perma-Fix TRU Services joint venture for the second phase of the project, which involves extracting up to 2,000 gallons of tank waste and converting the material into a solid at the nearby Perma-Fix Northwest plant. Once in a solid form, the material could be sent to the Waste Control Specialists low-level waste disposal facility in Texas.

“The challenges that face the tank waste mission at Hanford continue to mount,” Vance said in his letter, adding schedules need to be readjusted when “technical and fiscal realities” have caused delay. The Energy Department “reserves all of its rights” under the Tri-Party Agreement, and the consent decree, he said.