OAK RIDGE, Tenn. – Performing work on tall structures presents unique challenges. But when they’re also aging, they bring an even greater dimension to planning.
The 250-foot-tall chimney-like structure dates to 1949. It is still in use today, providing ventilation to operations at ORNL. The inspection helps the Oak Ridge Office of Environmental Management (OREM) and contractor UCOR determine what repairs are needed to support the stack’s remaining years.
“We’ve got a 74-year-old stack with some degradation,” UCOR Project Manager Ben Belyea said. “We’re doing an inspection to figure out what the lifespan of the stack is and determine what repairs are required to keep it operational in the future.”
In recent years, OREM and UCOR have used drones to conduct inspections to avoid having employees climb the towering structure, which could cause wear and tear on it.
However, information gathered from aerial photos proved the necessity for a full physical stack inspection. The latest climb, which began in February, is enabling the first physical inspection of the stack since 1995.
OREM expects the 3039 Stack to remain in place for 10 more years before it’s taken down, prompting the need to assess its condition and check for any needed repairs.
“We will find a small portion of the motor joints that need repair,” Belyea said. “After reviewing drone footage from a few years ago, we expect to see more repairs required as we move up the structure.”
After a yearlong planning effort, UCOR selected the International Chimney Corporation (ICC) as the vendor to conduct the inspection.
“Absolute no fear of heights is a good quality,” said Joe Brower, an ICC employee who climbs the stack. “We have good personnel with our company. We train our individuals well, and we have a training stack at our office.”
OREM and UCOR considered four options before determining the safest, most effective method to climb the aging structure. The selected method offers hands-free fall protection that increases worker mobility, safety and productivity.
The climb is taking place above a permanently installed platform 50 feet above ground. Stack inspectors are currently at the 208-foot level. They’ve installed 33 structural bands around the exterior of the stack and 16 ladder sections.
The crews inspect an average of five feet of the stack per day. They are scheduled to finish the inspection in the weeks ahead.