1940s stack at Oak Ridge National Laboratory gets repaired after crews climb 250 feet up

In Oak Ridge, the latest piece of deteriorating infrastructure from the 1940s to get a much-needed repair is also the tallest: a 250-foot stack at Oak Ridge National Laboratory built in 1949.

Unlike old nuclear reactors or chemical processing buildings that were vacant and unused for decades before being demolished, the 3039 stack is not just an iconic part of the skyline. It's still an operating stack, providing ventilation for the lab's waste operations.

That's why the Oak Ridge Office of Environmental Management and its contractor, United Cleanup Oak Ridge, had to coordinate with the lab to shut down operations as crews removed the top five feet of the tower and installed a new cap, UCOR said in a release on April 16. The two offices recently completed an $18 million life extension to the lab's waste operations.

“The 3039 stack, despite being one of the oldest structures at the site, still provides an essential function to ORNL operations,” said James Daffron, acting ORNL portfolio project director. “Maintenance is essential to ensure continued use of the facility.”

After using drones to inspect the stack for years and avoiding sending crews up the aging tower, UCOR contracted International Chimney Corporation – the company that built the 3039 stack 75 years ago – to do a physical inspection last year. It was the first physical inspection of the tower since 1995.

The stack won't tower over ORNL forever. The Oak Ridge Office of Environmental Management expects the stack to operate for 10 more years before it's taken down.

Oak Ridge is part of the world's largest cleanup effort

Oak Ridge is a critical site for the U.S. Department of Energy's Office of Environmental Management, the largest environmental cleanup effort in the world.

Focused on decades of waste from nuclear weapons production and nuclear research during the Cold War, the effort includes some of the most dangerous radioactive sites in the world. Of the 107 cleanup sites across the nation, whose area is equal to Delaware and Rhode Island put together, the office has finished cleaning up 92.

Oak Ridge cleanup is focused on ORNL and Y-12 National Security Complex, where addressing waste could take until 2050. To date, the Department of Energy has spent about $14.6 billion on cleaning up Oak Ridge, and could spend that amount again before it's finished.

UCOR has been the cleanup contractor for the Department of Energy in Oak Ridge since 2011. Its current 10-year contract with the department is worth $8.3 billion.

Daniel Dassow is a growth and development reporter focused on technology and energy. Phone 423-637-0878. Email daniel.dassow@knoxnews.com.

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