Staff Reports
WC Monitor
10/30/2015
Washington Closure Hanford has wrapped up its currently planned cleanup work within the fenced industrial complex of the 300 Area. Over the 16 years that cleanup has been ongoing in the 300 Area, much of it by Washington Closure and its predecessor Bechtel Hanford, 209 facilities have been demolished and 312 waste sites have been remediated. The six research reactors that once operated there are gone. “The dramatic changes in the landscape of the 300 Area underscores the substantial progress that has been made there,” said Jane Hedges, manager of the Washington state Department of Ecology’s nuclear waste program. The former industrial complex is the most publicly visible area at Hanford, serving as the gateway to the site just north of Richland. “It looks tremendously different,” said Dennis Faulk, Hanford program manager for the Environmental Protection Agency.
The lone building still standing that is included in environmental cleanup plans is the 324 Building. Work to tear down the building was delayed after a highly radioactive spill of cesium and strontium was discovered beneath it. The spill will be cleaned up and the building torn down in coming years as the Hanford budget allows. The few other structures that remain in the 300 Area are either being used by Pacific Northwest National Laboratory or continue to be used to support Hanford, including a fire station and a records archive. Some contaminated soil near those buildings or the utilities serving them will be cleaned up in future years as those structures are no longer needed. The only other 300 Area waste site that remains is a large disposal area on the west side of Stevens Drive, which is outside the 1,700-acre industrial complex of the 300 Area. The 300 Area was used as early as World War II to fabricate the uranium fuel used in Hanford’s nine plutonium production reactors in the 100 Area along the Columbia River and to research processes that eventually would be used at a larger scale at the reactors and in the 200 Area of central Hanford where irradiated fuel was processed to remove the plutonium.
The first Superfund cleanup work at Hanford started in the 300 Area in 1991, with a burial ground within a mile of the Columbia River picked as the first project. Hanford officials were concerned that about 100 drums containing uranium-contaminated solvent had been buried within a mile of the Columbia River. Other burial grounds that would follow held a range of items from drums of uranium shavings in oil to a locked safe holding a jug with plutonium in a liquid solution. A nuclear archaeologist at Pacific Northwest National Laboratory determined the jug held some of the first batch of weapons grade materials processed at Hanford and the second oldest known man-made plutonium 239. In 2001 buildings began to be demolished. Work on some buildings, such as the 71,000-square-foot 308 Building, took years to complete. It had 52 glove boxes and the complex included the Training, Research, Isotopes, General Atomics, or TRIGA, reactor.
Recent activities have included removal of the underground 340 Vault, which weighed about 1,100 tons, and removal of the Plutonium Recycle Test Reactor. The concrete pad that once held the underground reactor was buried in place and the soil above it reseeded as one of the final cleanup actions by Washington Closure within the 300 Area fence. It was among 51 acres of disturbed soil in the 300 Area that was seeded this fall with native vegetation that should come up in the spring. “We can take pride in the tremendous progress by our river corridor team,” said Scott Sax, Washington Closure president, adding that work had been done in close cooperation with DOE, the state Department of Ecology and EPA. During cleanup, the sign that identified each building by its number was hung along the Stevens Drive fence when the building was demolished. Those signs, which passing motorists on Stevens Drive had watched accumulate over the years, have been collected and saved for Hanford’s archive of artifacts.
Recent national and Hanford reports have addressed sequencing cleanup based, at least in part, on risk. “But there is something to be said for finishing work, for getting it done and declaring victory,” Faulk said. “I think that’s what’s been done in the 300 Area.” Lessons learned at the 300 Area will be used as the focus shifts to other Hanford cleanup, including work in the Central Plateau. “While the state is encouraged by the accomplishments in the 300 Area, some very serious and complex challenges remain to be addressed,” Hedges said. Many of the 300 Area facilities were unique and a smart choice was made to bring in specialty subcontractors, said Mark French, DOE project director for the Hanford river corridor. Specialty crane companies were hired for projects such as jacking the Plutonium Recycle Test Reactor straight up out of the ground and for the explosive demolitions of some structures, such as the below-ground housing for the reactor, which had concrete walls as thick as 13 feet. Keeping an open mind and listening to input from all workers contributed to success, said Dan Elkins, the 300 Area closure project manager for Washington Closure. A questioning attitude kept the 324 Building from being torn down shortly after much of the interior work had been completed, he said. Asking questions about how the building was constructed led to the discovery of a crack in the steel lining of a sump beneath one of its hot cells in 2010 shortly before the building was scheduled to be torn down. That led to probes in the soil beneath the building that collected readings from the cesium and strontium at up to 12,000 rad per hour, Elkins said. The building has been left in place as a radiation shield over the spill and to prevent precipitation from reaching it.
“The progress in the 300 Area has been incredible, with the amount of work that has been done to eliminate hazards close to the Columbia River and city of Richland,” said Stacy Charboneau, manager of the DOE Richland Operations Office. Much of the threat to the Columbia River has been eliminated with the remediation of waste sites, although work continues to protect the river from groundwater contaminated with uranium in the 300 Area. Contaminated buildings would have deteriorated over time and could have been infiltrated by birds and rodents that could spread contamination close to Richland city limits, Elkins said. “We’re really making the 300 Area safe for future use,” French said. The Hanford Comprehensive Land Use Plan calls for the industrial portion of the 300 Area to continue to be for other industrial purposes when cleanup is completed. But that could change for the prime land along the Columbia River with the city of Richland growing toward the north. “Leave it to the eye of the beholder what it could be,” Faulk said.
