Repairs completed on Oak Ridge's tallest stack
April 19, 2024; 6:07 p.m.

The 250-foot tall 3039 stack is one of the oldest structures at Oak Ridge National Laboratory, dating back to 1949. It is located in the heart of the site and provides essential support to ongoing operations. Image submitted

OAK RIDGE, TN – The iconic 3039 stack has towered over the Oak Ridge National Laboratory (ORNL) since the lab’s earliest days, providing ventilation to operations at the site. However, recent inspections revealed portions of the landmark had deteriorated and required repairs.

The Oak Ridge Office of Environmental Management (OREM) performs periodic inspections of the structure to identify any defects or other issues. In recent years, OREM and its contractor, UCOR, used drones to conduct those inspections to avoid having employees climb the towering structure, which could cause further wear and tear.

Information gathered from aerial photos proved the necessity for a full physical inspection. UCOR selected International Chimney Corporation as the vendor to conduct the inspection — the same company that built the stack 75 years ago.

Because of the amount of degradation at the top of the 250-foot stack, UCOR recently removed the top five feet of the structure and installed a new stack cap. During that period, operations connected to the stack were shut down.

Due to advanced deterioration of the 3039 stack, crews removed the top five feet of the structure and installed a new cap to stabilize and protect the top of the stack. Image submitted

Now, the repair work is complete, and operations have resumed.

“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.”

OREM expects the stack to remain in place for 10 more years before it’s taken down, so these repairs help ensure it continues operating safely in the heart of ORNL.

With the removal work completed, the stack has been successfully restarted and is once again providing ventilation to the site.

UCOR worked closely with ORNL management-and-operating contractor UT-Battelle and another site cleanup contractor, Isotek, to plan for the outage and ensure minimal impact to operations.