High-hazard Hanford waste pipes to be demolished via Tri-City Herald

A little more than a half-century ago, large cask trucks, heavily shielded to provide protection against radiation, would leave the Hanford 300 Area just north of Richland with loads of highly radioactive or particularly hazardous waste that researchers did not want buried too close to town.

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Work that started in 2011 to dig up those trenches is nearing completion, with the exception of some waste too close to the buried pipes to excavate until the pipes are cleaned up.

The trenches, used as early as 1954, also have revealed surprises.

Workers found a decontamination cell weighing at least 20,000 pounds buried in the trenches. It’s believed to have come from Hanford’s 327 Radiometallurgy Laboratory. The chamber was used from 1948-60 to decontaminate tongs, casks and other equipment that needed to be repaired.

“It was too big to lift with an excavator,” said Dave Martin, a Washington Closure project manager. A crane was brought in to remove it from the trench. It was wrapped in plastic and disposed of in the central Hanford landfill, the Environmental Restoration Disposal Facility.

Although historical drawings of the burial ground showed a tidy grid of trenches, workers have uncovered debris throughout the burial ground and deeper than expected, French said.

Workers expected to go down 20 feet, but waste has been found down to almost 35 feet. That’s in part because of sand that has blown in to cover the burial ground since it was closed in 1963.

By the time the trenches are excavated, DOE expects 2,000 drums of waste to be removed.

More than 600 drums are expected to be unearthed that are lined with concrete, a type of waste container not found in burial grounds cleaned up earlier at Hanford. A pipe was nested inside the concrete and used to hold waste with higher levels of radioactivity.

They likely were a waste disposal container that predated the vertical pipe units, Martin said.

If radiological surveys of the drums show they may contain transuranic waste, they are stored for eventual shipment to the Waste Isolation Pilot Plant in New Mexico. Other drums are destroyed, with their waste and concrete mixed with grout before they are sent to central Hanford for disposal.

Other drums have held uranium shavings in oil, uranium oxide powders and miscellaneous debris, all of which have been unearthed at previously cleaned up Hanford burial grounds. Construction debris from tearing down some old buildings also has been unearthed.

The trenches also have contained an unexpectedly high number of laboratory bottles — thousands of them, French said.

Read more here: http://www.tri-cityherald.com/news/local/hanford/article36739464.html#storylink=cpy