With dozens of cement trucks, two large batch plants and more than 1,000 workers scurrying about the Savannah River Site in South Carolina, the former nuclear-weapons production site appears to be a massive construction project.

In fact, the activity now supports a massive deconstruction project, boosted by a $1.4-billion federal stimulus infusion, to accelerate decommissioning and demolition of 75% of the legacy mission of the 310-sq-mile U.S. Energy Dept. site near Aiken before 2012.

D&D work had been ready and on the shelf for years, officials say. “This was a natural fit for the [American Recovery and Reinvestment Act],” says Mark Funk, deputy vice president for stimulus work of Savannah River Nuclear Solutions Inc. (SRNS), the site’s Fluor Corp.-led cleanup and operations manager.

Of DOE sites across the U.S., only the former Hanford production complex in Washington state received more ARRA money than SRS. Cleaning up the SRS site and shrinking its footprint will allow DOE to focus on future missions.

Jim Giusti, a DOE spokesman at SRS, says plans for stimulus work there are in keeping with the vision of Inés R. Triay, the agency’s assistant secretary of environmental management who wants to transform department liabilities. “We want to turn SRS into a national asset, with energy a key component,” he says.

Shaw Areva Mox Services, a joint venture of The Shaw Group Inc., Baton Rouge, La., and Areva Inc., the U.S. arm of the French nuclear firm, is building a $4.8-billion mixed-oxide fuel facility on- site to convert weapons-grade plutonium into nuclear fuel for electricity.

On Oct. 27, SRNS announced a memorandum of understanding with GE Hitachi Nuclear Energy, Wilmington, N.C., to explore developing and demonstrating a 299-MW modular nuclear reactor at the site. “This is another step that can put SRS and the region in an important role toward transforming America’s energy future,” says Garry Flowers, SRNS president and CEO.

SRNS—which includes Northrop Grumman, Los Angeles, and Honeywell, Morristown, N.J.—took over from a URS Corp.-led consortium late last year. Soon after, it landed the additional stimulus-related work. “There was a very quick ramp-up. That’s something you don’t normally see,” Giusti says.

However, last month, DOE issued a preliminary notice of violation for five worker-safety and health rule infractions, resulting in $3 million in lost contract fees to SRNS. Violations included a nitric acid spill in August 2009 and an electrical arc flash injury a month later. Funk says safety problems are taken seriously and result in a thorough examination of SRNS processes.

The stimulus mission is about 58% complete, highlighted by the Oct. 23 demolitions of two 145-ft tall, 700-ton nuclear reactor stacks by Controlled Demolition Inc., Phoenix, Md. Rubble from the stacks will be disposed of below grade and grouted in place in the reactor buildings, part of the unusual in situ decommissioning of the two reactors, called P and R.

Under the D&D plan, crews will fill all structures belowground with grout while entombing aboveground portions of the buildings with concrete. About 240,000 cu yd of grout will be used for the two 1950s-era reactor buildings. A self-healing integral crystalline waterproof roof with a 10,000-year life will be placed atop the buildings.

Reactor decommissioning is much less expensive and more effective than demolishing buildings and hauling waste somewhere else, says Funk. SRS will remain in government hands, so the sites will always be secure, he adds. Total cost to D&D the two reactors is about $200 million.

Before entombment can occur, all metal is stripped from building exteriors and all openings—one reactor has 120 openings—are filled.

SRS awarded Champion Concrete, Iron Mountain, Mich., a $33-million contract for two batch plants to produce up to 240 cu yd per hour of concrete. Much of the grout and concrete has to be specially formulated...