A limited ramp-up of construction can begin at a key facility where work has been slowed at the Hanford vitrification plant, Energy Secretary Steven Chu and Washington Gov. Chris Gregoire announced late Tuesday afternoon.
In addition, the Department of Energy is considering sending radioactive waste directly to the plant's treatment facilities before the Pretreatment Facility, which is plagued with technical issues, is completed.
Bypassing the Pretreatment Facility could help DOE meet a legal deadline to start treating waste for disposal in 2019.
Construction re-mains on hold at the Pretreatment Facility, the largest building on the vitrification plant campus. But at a second key facility where construction was slowed, the High Level Waste Facility, building could resume in some areas.
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Gregoire, who leaves office today after eight years as governor, had pledged to get the $12.2 billion vitrification plant on track toward completion before leaving office.
"Over the past several months, the Department of Energy and the state of Washington have worked together closely to ensure the Waste Treatment Plant is on a stable path to resolving the technical issues, completing construction and beginning to treat waste in the coming years," Chu and Gregoire said in the joint statement.
Construction slowed or halted on the two vit plant facilities that will handle large amounts of high-level radioactive waste amid persistent questions about whether the plant, as designed, will operate safely and efficiently.
Last summer, Chu picked a team of what he called some of the nation's brightest individuals to review technical issues at the plant, and they met for several days with Chu at Hanford in September.
Based on insight gathered from those experts and other reviews, DOE now better understands what work will be needed to resolve the technical issues at the High Level Waste Facility, said Chu in a letter to Gregoire made public Tuesday.
The Pretreatment Plant is planned to separate radioactive waste streams left from the past production of weapons plutonium at Hanford into high level and low activity waste streams. Then the High Level Waste Facility and the Low Activity Waste Facility will immobilize the waste in glass for disposal.
Plans announced Tuesday call for continued work at the High Level Waste Facility to redesign black cells where waste will be mixed with two pulse jet mixers. The mixers have no moving parts because the black cells will be too radioactive for workers to enter once construction begins. Quality assurance work also is needed, according to the letter.
But construction at the rest of the High Level Waste Facility not affected by technical issues can be ramped up, the letter said. DOE is moving forward to redirect money for the work, it said.
However, the overall budget for the vitrification plant is not expected to increase.
DOE continues to make plans to address major technical issues at the Pretreatment Facility, including keeping waste well mixed to prevent a buildup of flammable gases or an unplanned nuclear reaction. It also is looking at possible erosion and corrosion that could limit the life of the plant, in part because of increased mixing to keep plutonium and other particles from settling to the bottom of tanks.
Pretreatment Facility construction will be limited until those technical issues are addressed, Chu said.
One possibility DOE is considering based on the advice of Chu's experts is bypassing the Pretreatment Facility to allow some waste to go directly to the High Level Waste Facility and Low Activity Waste Facility for glassification.
"Those options could enable the project to start treating waste before the completion of the Pretreatment Facility and would increase the flexibility and reliability of the Hanford tank waste mission overall by building additional redundancy into the operations," Gregoire and Chu said.
To resolve issues at the Pretreatment Plant, full-scale testing of pulse-jet mixers with simulants that reflect the physical and chemical characteristics of the waste is planned, Chu said in the letter.
A leadership team for the testing is being picked and could include experts from Pacific Northwest National Laboratory in Richland, Savannah River National Laboratory in South Carolina and other national laboratories, industry and the academic community, Chu said.
Those experts will define the test objectives and plans, specify instrumentation requirements, develop the simulants and evaluate the test data, he said.
More work to resolve additional technical issues also is planned. That includes more testing and design changes to address erosion and corrosion; adding redundancies to some processes; adding technologies to monitor the structural integrity of tanks and equipment within black cells and structural upgrades for installed tanks and equipment.
In addition, DOE will consider whether there is a need to "pre-condition" waste in the tank farms were the 56 million gallons of waste to be treated is stored. A process or technology could be used to make sure large or extremely hard particles of waste are not sent to the Pretreatment Facility, where they could contribute to erosion and corrosion.
Chu also told Gregoire he appreciated her engagement to define an approach for resolving technical issue.
"This model of interaction between the state of Washington and DOE builds trust and enhances communication while preserving our respective roles as the owner of the cleanup and the regulator," he said in the letter. "We look forward to continuing this constructive working relationship."
While construction has been delayed at the Pretreatment Facility and High Level Waste Facility, it has proceeded at other parts of the vitrification plant. The Low Activity Waste Facility is 61 percent complete and the Analytical Laboratory is 65 percent complete.
-- Annette Cary: 582-1533; firstname.lastname@example.org; Twitter: @HanfordNews