The Department of Energy needs to immediately begin work on adding more tanks to hold Hanford's high-level radioactive waste, Oregon Gov. John Kitzhaber said in a letter to Energy Secretary Steven Chu.
The request comes after DOE found a leak last year in the interior shell of Hanford's first double-shell tank.
The leak, combined with issues at the Hanford vitrification plant being built to treat the waste and the need to empty waste from older single-shell tanks, demands immediate action to develop additional tank capacity, Kitzhaber said in the letter.
The letter was sent Jan. 17 and circulated Tuesday to members of the Hanford Advisory Board.
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"Funding for new tank capacity should be in addition to the current level of Hanford funding," the letter said. "We should not have to defer planned cleanup work to resolve this problem."
New Washington Gov. Jay Inslee has not publicly addressed the tank issue in his first two weeks in office. But the Washington State Departments of Ecology and Health are part of an integrated project team at Hanford working on the issue with the Department of Energy and its contractor, Washington River Protection Solutions.
The team is considering all options, including a recommendation of the Hanford Advisory Board to build more waste tanks, the contractor said earlier this month.
DOE has said that building one double-shell tank could cost about $100 million, and building a group of six tanks could take five to seven years.
Hanford has 28 double-shell tanks, which are used to hold waste emptied from 149 older, leak-prone single-shell tanks that date to as early as World War II. Hanford has 56 million gallons of waste left from the past production of plutonium for the nation's nuclear weapons program.
Some, if not all, of the waste will be turned into a stable glass form at the vitrification plant under construction. The plant legally is required to start treating the waste in 2019, but DOE has said technical issues make its schedule uncertain.
A leak of radioactive waste from the inner shell of Hanford's oldest double-shell tank, Tank AY-102, was confirmed in October. It was designed to be used for 40 years and is just past that age now.
The slow leak of an estimated 190 to 520 gallons is confined within the space between the inner and outer shells of the tank.
An inspection of the second double-shell tank built, Tank AY-101, found no evidence of a leak, and the results of the inspection of a third tank, Tank AZ-101, should be available soon.
The Oregon Hanford Cleanup Board, which advises Kitzhaber on Hanford environmental cleanup, recommended the additional storage for high-level radioactive waste.
"The board does not make this recommendation lightly," Kitzhaber said in the letter. "It understands that building additional tank capacity is not a permanent solution for Hanford. It just buys us a bit more time."
The Tank AY-102 inner leak makes it even more important that vitrification plant technical issues be resolved and federal budgets support its completion, preferably without losing further ground in the schedule, the letter said.
Planning for new tanks should be coordinated with the need to blend, mix and stage waste to feed to the vitrification plant, the letter said. Tank AY-102 had been planned to be used as one of 15 double-shell tanks to feed the plant.
The primary strategy should continue to be Hanford cleanup moving forward expeditiously to protect the Columbia River, Kitzhaber said.
"However, from a tactical standpoint, we cannot count on the (vitrification) plant to be in operation in time to alleviate the need for additional tank storage capacity," he said in the letter. "Nor can we count on the existing tanks indefinitely."