The Department of Energy is making good on an agreement not to bring radioactive waste from its other sites to Hanford until the vitrification plant is operating to treat waste already here.
The agency is expected to publish a "record of decision" today, adopting a range of environmental cleanup plans for the Hanford nuclear reservation based on a 10,000-page study that has been in the works for a decade.
Hanford Challenge earlier put the cost of the study, the Hanford Tank Closure and Waste Management Environmental Impact Statement, at $85 million.
It will guide cleanup and waste management decisions at Hanford for decades to come, said Suzanne Dahl, the manager of the state Department of Ecology's tank waste treatment section.
The new decisions made by DOE based on the study include the fate of the Fast Flux Test Facility -- tear it down -- and what to do with underground tanks after radioactive waste is pumped from them -- leave them in the ground.
However, DOE has postponed a decision on one of the most difficult topics included in the study -- how to treat all 56 million gallons of radioactive waste held in underground tanks. The waste is left from the past production of weapons plutonium.
The Hanford vitrification plant under construction was planned to be large enough to treat all high-level radioactive waste from the tanks, but not large enough to treat all the low-activity radioactive waste. Expanding the vitrification plant or looking at alternate technologies for the remainder of the waste has been proposed.
The decision to continue the ban on importing other DOE waste to Hanford implements a 2006 settlement agreement between DOE and the state Department of Ecology. The state had sued DOE over missed legal deadlines for emptying underground tanks and treating their waste.
The commitment not to import waste until the vitrification plant is fully operating, possibly in 2022, was included in the study document, but there was concern, particularly by watchdog groups, that the commitment was not binding without a record of decision. The study showed that disposal at Hanford of proposed waste from other DOE sites would significantly increase the risk to groundwater, according to the Department of Ecology, which cooperated in the study.
However, watchdog group Heart of America Northwest said Thursday the record of decision left a loophole that could allow DOE to import waste sooner. If the startup of the plant is delayed, which is likely because of technical issues, DOE could change the record of decision to start importing waste at any time, it said.
The record of decision will formalize the standard already being used and require that 99 percent of waste be emptied from underground tanks.
Consideration was given in the environmental study to leaving up to 10 percent of the difficult-to-retrieve waste in tanks. But that could contaminate groundwater in the future to levels that exceed safe drinking water standards, Dahl said.
The DOE decision will call for leaving Hanford's single shell waste tanks in the ground after 99 percent of waste has been retrieved and filling them with grout.
That's been somewhat controversial, largely because of the contaminated soil beneath some tanks. An estimated 1 million gallons of waste have spilled and leaked from the tanks into the ground.
Heart of America called leaving the tanks in the ground a decision to cover up, not clean up leaks from the tanks.
DOE decided to leave the tanks in place in part to reduce worker exposure to radiation and because of technical uncertainties, according to the record of decision. Those benefits outweigh the potential groundwater benefits of digging up the tanks, treating remaining waste and disposing of them in pieces in a lined landfill nearby in central Hanford, according to DOE.
However, it is the state of Washington that likely will have the final decision on whether tanks are left in the ground or dug up.
Closure of the tanks requires a state permit and the state will issue permits tank farm by tank farm, Dahl said. Public comment would be accepted before state permitting decisions on the tanks are made.
The environmental study provides some convincing analysis to leave tanks in place, however, she said.
The record of decision will call for work to remove hot spots of contamination in the soil or to treat the underground waste to protect groundwater while leaving the tanks in place.
The decision on the Fast Flux Test Facility, a 400-megawatt research reactor, will call for removing above-grade structures but leaving below-ground structures in place. They would be filled with grout to immobilize remaining radioactive and hazardous constituents.
The reactor has not operated since 1992 and previous Democratic and Republican administrations concluded the nation had no financially viable mission for the reactor, despite Tri-City interest in using it to produce isotopes for medical use.
"The completion of this record of decision is a significant step toward achieving the cleanup mission at Hanford," said Ken Picha, DOE's deputy assistant secretary for tank waste and nuclear material, in a statement.
-- Annette Cary: 582-1533; email@example.com; Twitter: @HanfordNews