The Department of Energy's plan to wait at least two years to pump radioactive waste from a damaged double-shell tank at Hanford is unacceptable, the state of Washington says.
DOE's plan "demonstrates the federal government's lack of commitment to set a firm, near-term schedule for the removal of waste from leaking double-shell Tank AY-102," the state Department of Ecology said in a statement Monday.
DOE confirmed in October 2012 that Tank AY-102, the oldest of Hanford's 28 double-shell tanks, had leaked waste from its inner shell. The waste then was in two places in the space between the inner and outer shells, and DOE says no waste has breached the outer shell to reach the soil beneath the underground tank.
The state sent DOE a strongly worded letter in January saying it expected a plan to empty the tank that would meet state requirements to remove waste as soon as possible. DOE's initial plan, as the state understood it, was to take no action to remove waste from the tank until conditions worsened.
DOE gave the state its revised plan late Friday, and the state said the plan admits the federal government's obligation to remove the waste from the damaged tank. But waiting at least two more years to start pumping waste is neither legally acceptable nor environmentally prudent, it said.
The plan lays out a schedule for engineering, purchasing and installing equipment outside the tank, which would be completed in November 2015.
Then DOE would evaluate the situation, determining when waste retrieval equipment should be installed inside the tank and when waste removal should begin. Removal of the waste and its transfer to a sturdier double-shell tank would begin no sooner than March 2016, the plan said.
"On initial review, the plan lacks accountability to meet state law," the Department of Ecology said.
The state does not have confidence that any of the dates in the plan can be met because of potential events that could cause further delays, it said.
Last week, DOE announced that waste had been discovered in a third place on the floor of the space between the tanks.
That reinforces the need to need to start pumping liquid waste now, the Department of Ecology said.
DOE already has installed equipment to allow liquid waste to be removed from the tank, but would take at least two more years to install and begin operating equipment that also could pump up the sludge that is beneath the liquid in the tank. The tank has a capacity of 1 million gallons.
DOE does not want to begin pumping any waste until it is ready to pump the sludge. The liquid helps cool the sludge, which generates heat as it radioactively decays. Heat can increase corrosion rates in the tank and contribute to generating potentially flammable hydrogen gas.
DOE also has single-shell tank issues to consider. Waste from Hanford's 177 single-shell tanks is being pumped into its double-shell tanks, which are nearing capacity, until the waste can be treated for disposal. At least one single-shell tank is leaking waste into the ground beneath it and 67 are suspected of leaking in the past.
"We recognize the issues that (DOE) is concerned with regarding available tank space, cost and the absence of immediate danger to the public," the Department of Ecology said. "However, those do not mitigate the need to take all precautions to avoid further risk to human health and the environment."
w Annette Cary: 582-1533; email@example.com; Twitter: @HanfordNews