Benedict Ubamadu stops to look at a large sign while touring the Y-12 National Security Complex's New Hope Center early Wednesday afternoon. Y-12 is building a new Uranium Processing Facility whose timeline and cost continue to rise.

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Y-12 TIMELINE * 1943 - Construction started on Y-12 plant toward goal of making enough enriched uranium for an atomic bomb. * 1945 - More than 22,000 workers are employed at the site. * 1954 - First batch of thermonuclear parts assembled and shipped from Y-12. * 1967 - Y-12 produces NASA "moon boxes" to bring back lunar surface geological samples to Earth. * 1972 - Y-12 begins stockpile surveillance to study effects of aging on nuclear weapons. * 1989 - Cold War production led to 8,000 people working around the clock to make nuclear weapons. * 1992 - First nuclear weapon disassembled for storage at Y-12, beginning a new storage mission. * 2005 - Initial UPF design begins. * 2013 - Plans announced for an Oct. 31 meeting in Chattanooga related to UPF construction. Source: Y-12 ABOUT THE NAME "Y-12" apparently doesn't stand for anything particular but was just a code name during World War II. Historians told WBIR-TV that it was picked randomly as to not give anyone a clue to its purpose and that "X" and "Y" were chosen as a familiar symbol for unknowns.

OAK RIDGE, Tenn. - Nestled in a lush green valley here is what's billed as the Volunteer State's biggest construction project since World War II.

And that's even before the final cost of the Uranium Processing Facility at the Y-12 National Security Complex is known. Estimates put the UPF's price tag at $4.2 billion to $6.5 billion, with a more accurate figure slated to be finalized next year.

The UPF, which will be the size of what one official called "a Home Depot and a half," will replace an aging facility that helped pioneer the atomic age in the 1940s and since then has played a key role in the country's national security.

Officials said UPF will provide a more modern site for maintaining and dismantling nuclear weapons. It will help the nation sustain operable nuclear capabilities while blending highly enriched uranium for other uses, including nonmilitary, they said.

Built during World War II to help create the atomic bomb, the sprawling Y-12 facility's role now is to process and recycle enriched materials and do nuclear component manufacturing and testing. It disassembles weapons, disposes of materials and does packaging and storage. Located near Oak Ridge National Laboratory, it sits on 811 acres, 150 of which are "high-security." More than 6,700 people work at Y-12.

John Eschenberg, the UPF project director, said the planned new facility is "a game-changer for what we do here and in East Tennessee." It also will offer lots of opportunities for East Tennessee businesses to benefit from the huge capital investment as well as future ones as companies learn how to participate in federal projects.

"We're building six and a half Volkswagen plants here," he said, citing the $1 billion cost of the Chattanooga auto assembly plant. Y-12 officials said the investment will rival the entire World War II-era Manhattan Project in Tennessee if that initiative were put in today's dollars. In raw dollars, UPF is billed by officials as the largest capital investment ever in the state.

However, Eschenberg told a group of Chattanoogans recently that when he arrived at Y-12, he was surprised by its aging facilities.

"When I came here, I was embarrassed," he said. "I thought I was in the Soviet Union."

Richard Brown, who's handling procurement for UPF, said much has changed in 60 or 70 years, and UPF will be a chance to upgrade equipment and technology.

Construction codes, for example, have become more stringent, he said, adding there will be more modern equipment and a more efficient and safe environment for workers. All that is helping drive the massive cost of the facility.

The UPF construction project will run until 2025 when the facility is expected to become operational.

Brown said there's a long construction time line because of UPF's complexity and technology. He compared it to the time it takes to build a nuclear power plant.

"These are the 10-yearish scale of projects," he said.

SLICE OF BUSINESS

Officials said UPF will offer a chance for Chattanooga-area builders and suppliers to get a slice of business from the project.

Brown estimated that between $1.7 billion and $2.7 billion worth of materials and equipment will be needed.

"Half the value of the project is in the hands of our supply chain," he said.

Plans are to meet Oct. 31 in Chattanooga with potential suppliers locally, Brown said.

U.S. Rep. Chuck Fleischmann, R-Tenn., said UPF is "going to be huge" and it's going to generate lot of business.

"I want to make sure Chattanooga and Hamilton County businesses can share in it," he said.

Ron Harr, the Chattanooga Area Chamber of Commerce's chief executive, agreed that UPF is not just important to national security, it's an opportunity for local companies to get "a significant piece" of the work to build the facility.

Eschenberg said UPF is seen as helping Y-12 be much more than "a bomb plant."

"We're working to modernize," he said. "UPF is the cornerstone."

In addition to Y-12's weapons mission, it blends highly enriched uranium into nonweapons-grade material for use as nuclear fuel for the U.S. Navy, Brown said. Also, fuel is blended for power generators such as TVA's nuclear reactors, and material can be used for research as in medical isotopes, he said.

"We do beat swords into plowshares," Eschenberg said.

UPF FUNDING

While Y-12 gets its funding from Congress in an annual allocation, President Barack Obama and congressional leaders are seen as supporting the project, said Bridget Waller, community and government relations manager for Y-12.

"We feel confident about the funding," she said. 'It's essential. This is a must-have, not a want-a-have."

However, the project has its opponents. U.S. Sen. Ed Markey, D-Mass., has introduced legislation that would terminate UPF and other nuclear weapons facility projects.

"With current budget constraints, we should not spend billions in taxpayer dollars to build new nuclear bomb facilities at the same time we are reducing our nuclear stockpile," Markey wrote in a letter last year.

Meanwhile, preliminary work has begun at the UPF site, said Brown. A road is being rerouted and some abandoned power lines and poles are undergoing removal, he said.

Contact Mike Pare at mpare@timesfreepress.com or 423-757-6318.