The Department of Energy has met a legal deadline three months early for cleaning up five waste sites and a burial ground at Hanford just north of Richland.
It's part of work at Hanford's 300 Area, where Washington Closure Hanford has torn down 71 buildings in addition to some buildings torn down by previous contractors.
Washington Closure is working to complete cleanup of the area, which once was used for research and to fabricate fuel for Hanford's plutonium production reactors, by the end of 2015. The Tri-Party Agreement has set a series of legal deadlines to keep the cleanup on track, including the latest deadline to be met.
"We're making tremendous strides in cleaning up the river corridor," Mark French, DOE project director, said in a statement. "Cleaning up these contamination sources helps protect the Columbia River and reduce our footprint of active cleanup."
Washington Closure and its subcontractor Terranear PMC removed more than 60,000 tons of waste, taking it to a central Hanford landfill for low-level radioactive waste, to meet the deadline.
The deadline covered the final 300 Area burial ground to be cleaned up -- the 618-1 Burial Ground, which was one of Hanford's earliest. It was used to bury waste from the end of World War II through 1951, with the expectation at the time that the waste was being permanently buried, so few records were kept on its contents.
In addition to three 20-foot-by-180-foot trenches, the burial ground had a larger area that was used in the 1960s as a pit to dispose of and neutralize acids after the rest of the burial ground was closed.
The burial ground turned out to have less hazardous materials than expected.
Workers uncovered about 60 labware bottles, some with detectable radioactivity, but none that appeared to include plutonium.
Crews were prepared to find drums of potentially flammable uranium chips, but the only intact drum recovered was filled with oil, possibly motor oil.
Workers did find some of the expected graphite crucibles, but only 50 -- not the hundreds they anticipated. The crucibles, each about 2 feet tall, were used in the fuel cladding process and soaked up 50 to 100 pounds of uranium.
The five waste sites included slabs left after buildings were torn down or ground that was contaminated with radioactive materials. Work began on the first waste site in September 2008 and remediation was completed on the final waste site in the series a year later. Regulators recently completed documentation agreeing cleanup to meet the deadline was completed on both the waste sites and the burial ground.
Washington Closure still has some difficult work ahead in the 300 Area, despite the dramatic change in the skyline there as significant cleanup work has been completed.
Work began last year on below-ground contamination in the northern part of the 300 Area, where buildings have come down.
The DOE contractor also faces some of its most hazardous building demolition work yet to be done on some remaining large buildings and heavily contaminated buildings in the 300 Area.
"They're cranking away," said Larry Gadbois, a scientist for the Environmental Protection Agency, regulator for the work.
He noted there have been some work delays to check or recheck for beryllium contamination, as the contractor has taken the issue of worker exposure to beryllium seriously over the past several years. Dust from beryllium, left from uses such as fuel fabrication, can cause an incurable lung disease in workers who are sensitive to the metal.
w Annette Cary: 582-1533; acary @tricityherald.com; more Hanford news at hanfordnews.com