U Canyon buildings at Hanford coming down

After months of preparation at Hanford's first huge processing canyon to be demolished, Hanford workers have gotten to some of the "fun part."

That's what Mike Swartz, deputy project manager for deactivation and demolition at CH2M Hill Plateau Remediation Co., called the work of the shears mounted on an excavator that were tearing away at the walls of a U Plant processing building Wednesday.

"This is the skyline-changing stuff," said Cathy Louie, Department of Energy deputy project director. "It's been out here from the '40s."

U Plant is one of five processing plants at the Hanford nuclear reservation built to chemically separate plutonium from fuel rods irradiated in Hanford reactors for the nation's nuclear weapons program.

The plants often are called canyons because of their high ceilings, narrow width and long walls. U Plant, at 810 feet long, is longer than Seattle's Space Needle is tall.

"This will be the first canyon demolition at Hanford," Swartz said. "It's the lead-off for the four others."

Work is starting at U Plant in central Hanford because it may turn out to be the least difficult to decontaminate. Built during World War II, it never was needed to process fuel to extract plutonium.

Instead, it initially was used to train operators of two other chemical processing plants, then converted to recover uranium from waste generated by the other plants for about five years in the 1950s.

DOE approved a plan for demolishing U Plant in central Hanford in 2005 but did not have the budget to proceed until Hanford received $1.96 billion in federal economic stimulus money.

DOE is spending $50 million, including $34 million in stimulus money, to prepare the canyon for demolition. In addition, $17.8 million, most of it stimulus money, is being spent to tear down the buildings and tanks that surround the canyon.

Work is just beginning to demolish the processing buildings for the canyon, where uranium in liquid form from U Canyon and also the PUREX processing plant was turned into a uranium trioxide powder.

Fifteen tanks that once held chemicals used in the canyon or processing buildings already have been demolished. The largest had 100,000-gallon capacities.

CH2M Hill expects to have the processing buildings also torn down and the rubble from them taken to the Environmental Restoration Disposal Facility, a landfill for low-level radioactive waste, by the end of July.

Some office buildings already have been demolished, but a stack and other facilities used for ventilation within the canyon will have to remain until more work is completed inside the canyon.

When work started inside the canyon, the floor was cluttered with 125 major pieces of equipment, such as compressors and pumps, plus miscellaneous piping and other smaller items.

About 90 percent of that equipment has been moved so far into empty spaces in the 40 processing cells below the deck of the canyon. The deck is expected to be cleared by the end of the month.

A subcontract should be in place by the end of August to fill the basement cells with 23,000 cubic yards of grout, Swartz said.

The $67.8 million available for the U Plant complex should have the ancillary buildings removed and the canyon ready for demolition by 2012.

Because of the 5-foot-thick walls of the canyon, CH2M Hill is looking at the possibility of using explosives to bring down the walls.

Plans call for the ceilings and walls to be collapsed and the rubble backfilled and covered with an environmentally protective earthen cap that would form a berm standing 40 feet high along the length of the former processing canyon.

-- Annette Cary: 582-1533; acary@tricityherald.com; more Hanford news at hanfordnews.com