HANFORD — Hanford workers have dug up debris ranging from radioactively contaminated forklifts to drums of potentially flammable material while completing cleanup of 11 waste sites just north of Richland.
The work, started in 2002, was completed this month nearly two years ahead of a legally binding Tri-Party Agreement deadline.
"The river corridor people have just been cranking away on this work," said Larry Gadbois, a scientist for the Environmental Protection Agency, which regulates the Department of Energy work. "It's been pedal to the metal on waste sites."
Contractor Washington Closure Hanford is 8 percent ahead of schedule and has saved $170 million in costs for work to clean up Hanford along the Columbia River, said Washington Closure spokesman Todd Nelson. It's used those savings to accelerate work to finish the 11 waste sites.
They include some smaller sites with contamination near the surface, but five of them were burial grounds where Cold War workers believed they were disposing of debris and other waste permanently. Modern cleanup standards have led to the sites being excavated to protect the Columbia River.
Workers on the 11 sites have excavated 426,000 tons of soil. Work was started by a previous contractor, Bechtel Hanford.
One of the most hazardous and challenging burial grounds was 618-7, where Washington Closure workers dug up more than 800 barrels of hazardous materials, 100 drums of zircaloy shavings and 16 stainless steel tanks, including at least one containing an oxide of radioactive thorium.
In other burial grounds, workers uncovered five forklifts and a flatbed trailer. One of the most unusual finds was a safe in the 618-2 Burial Ground that still held a jug of plutonium.
Nuclear archaeology at Pacific Northwest National Laboratory traced its origins to the first batch of weapons-grade material ever processed at Hanford. It's the world's second oldest known man-made plutonium 239.
Work at the 618-2 Burial Ground "fundamentally changed the way we clean up waste sites at Hanford -- from how we protect people to how we manage the site and unknown items we discover along the way," said John Darby, a project manager for Washington Closure.
"It totally changed our approach to remediation," he said.
River corridor cleanup strategies now keep people away from waste as much as possible and just one to five drums are unearthed at a time before work is done to identify their contents, Nelson said.
"What we learned from the hazards of the early waste sites gave us a tremendous leg up on the tougher burial grounds," said Dave Brockman, manager of the DOE Hanford Richland Operations Office, in a statement.
Most of the waste sites just outside the fence of the 300 Area just north of Richland now have been cleaned up.
However, work is under way to learn more about one of the most hazardous burial grounds, 618-10. There some highly radioactive material sealed into cans at the 300 Area were dropped down pipes set vertically into the soil.
-- Annette Cary: 509-582-1533; email@example.com.