Savannah River Site

Bechtel Nearing Completion of $500 Million Tritium Extraction Facility Project for DOE

By Debra Wood

Bechtel Savannah River Inc. will wrap up construction early next year on a $506 million Tritium Extraction Facility at the Department of Energy's Savannah River Site industrial complex at Aiken, S.C.

The United States uses the radioactive gas tritium as a component in the triggering mechanism of nuclear weapons. The new tritium facility is part of the Department of Energy, National Nuclear Security Administration's Defense Programs operations at Savannah River.

The country stopped producing tritium in 1988 and has relied on recycled tritium from dismantled or existing weapons. Tritium decays about 5 percent annually. It needs to be replenished in existing weapons.

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"The whole purpose of this half-billion dollar investment is to extract tritium that has been produced in a commercial nuclear reactor," said Clay Ramsey, the facility's program manager for DOE, NNSA. "We have new, first-of-a-kind equipment to do that work, but that has been a challenge. While we have made tritium before, we have not made it this way."

The Team

Construction manager Bechtel Savannah River - a division of Bechtel National Inc., the high-technology government contracting arm of San Francisco-based Bechtel Group - designed and engineered the facility, which is called the TEF, and broke ground in July 2000. It worked with the DOE on plans.

Adding to the length of time for construction, vendors had to develop manufacturing techniques to construct the equipment. For instance, the 40-ft. long gloveboxes, which allow workers to handle the hazardous materials through gloves attached to the airtight units, had to be ordered nine months prior to installation.

"We started construction before the design was complete," said Tim Richardson, TEF deputy construction manager for Bechtel Savannah River. "We spent 18 months building the concrete structures while the design was evolving for the building internals."

The Washington Group International of Arlington, Va., is completing testing and serves as the start-up authority. It has about 100 people onsite. It expects to begin testing with inert gas in 2005 and approve the site for normal operations by 2007. Westinghouse Savannah River Co. of Aiken will operate the plant.

In late May, the construction company turned over the first two process systems for testing. Construction was 90 percent complete and the project 10 months ahead of schedule as of August.

"I'm proud of the quality of work (Bechtel) workers have done that has allowed (Washington Group) to accelerate its start-up schedule," Richardson said. "Quality is of utmost concern."

At peak construction, 500 craftspeople were working onsite. Design and construction costs amounted to $300 million, the equipment another $100 million and start-up costs $100 million.

The structures

Three steel-reinforced concrete structures comprise the extraction facility: the remote handling building, tritium processing building and tritium support building. The support structure will have a brick facade.

Highly radioactive extractions will take place in the handling building, which has 6-ft.-thick walls, ceiling and floor. The walls in the processing building, where preliminary purification of the tritium will be done, are 1 ft. thick. The thick walls provide protection against radiation exposure and natural hazards, such as earthquakes or tornadoes.

Bell Construction of Rochester, N.Y., performed the concrete work. Nineteen-thousand cu. yds. of concrete were used during construction. Crews added liquid nitrogen to the mix to maintain the temperature below 70 degrees.

The processing and support facilities are slab on grade. The taller handling building required pile driving and excavating up to 40 ft. below grade. Proximity of nearby buildings precluded sloping the hole. The handling building is 70 ft. high inside. Installation of a 165-ton shield door required a 1,000-ton crane.

The processing building is a single story, about 48 ft. tall, 125 ft. wide and 155 ft. long, and it's crammed full of equipment. It will house the control rooms and areas for gas analysis and radiation control activities. The support building houses management staff, changing rooms and maintenance support areas.

Equipment

Bechtel is self-performing installation of all specialty equipment, including gloveboxes, piping, electrical, instrumentation and control system work. There are hundreds of thousands of feet of cable and conduit and tens of thousands of terminations.

Merrick & Co. of Aurora, Colo., designed and built each of the nine gloveboxes in three pieces. The exterior consists of 7-gauge stainless steel and safety glass. The gloveboxes are airtight and contain argon inert gas and equipment for processing the tritium.

The gloveboxes were transported to the site from Denver and North Carolina. Crews lifted the boxes through a removable hatch in the handling center's roof, with only a quarter of an inch to spare.

"We tasked the vendor, who was fabricating the gloveboxes, to build them in segments that would fit within the envelope to get them inside," said Mike Hickman, TEF federal project director for DOE, NNSA. "When the shell arrived at the site, Bechtel assembled the internals and gloveboxes."

Equipment reaches about halfway up the interior of the handling building, with the balance clear to enable the remote 30-ton crane to function. Operators will conduct all routine work remotely from a console located far from the area containing the tritium. A separate 125-ton crane will lift casks shipped to the facility.

Safety

All work was performed without a lost-time injury. Safety is a core value for Bechtel and the entire Savannah River Site. The complex has logged more than 14 million hours without a lost-time injury. The last construction mishap occurred six years ago.

The culture of safety starts with management but flows both ways. Employees are encouraged to promptly report any safety concerns. Craftspeople are self-policing and reinforce safe behaviors.

"This is an exceedingly dangerous construction project and they have been able to pull this off without any serious injuries, and the quality is exceptional," Ramsey said.

Project Team:

Owner: United States Department of Energy
Construction Manager/Designer: Bechtel Savannah River Inc., Aiken, S.C.
Testing/Start-Up Authority: Washington Group International, Arlington, Va.
Concrete Contractor: Bell Construction, Rochester, N.Y.

Useful Sources:

Savannah River Site
http://www.srs.gov

Merrick & Company
http://www.merrick.com/