The Department of Energy’s Oak Ridge Office of Environmental Management and contractor UCOR have begun removing the two remaining structures at the former radioisotope development laboratory at Oak Ridge National Laboratory, in Tennessee.
“This project launches our next phase of major demolition and cleanup at ORNL,” said Nathan Felosi, ORNL’s portfolio federal project director for OREM. “Our work is eliminating contaminated structures, like this one, that are on DOE’s list of high-risk facilities and clearing space for future research missions.”
The project is scheduled to be completed this spring, OREM reported on February 23.
Hot cells: The structures being demolished are hot cells, heavily shielded concrete rooms that provided researchers protection from highly radioactive material during the years the radioisotope development lab was operational.
Constructed in the early 1940s, the lab contained six hot cells where radioisotopes from ORNL's graphite reactor and succeeding reactors were processed for shipment.
Getting ready: UCOR completed several tasks to prepare the final structures for demolition. Workers eliminated contamination pathways, which involved pumping and grouting a 47-foot-long underground transfer tunnel that was used to load radioactive material into the hot cells.
UCOR also constructed a six-story protective cover over the hot cells to keep nearby research facilities protected during the demolition. Using a 175-ton crane, crews set a foundation of 92 blocks weighing 16,000 pounds each. Workers then used the crane to erect 20 steel trusses for the protected cover's frame. Nearly 12,000 square feet of fabric was added to the frame to complete the protective cover.
Waste transport: An intermodal rail system was built to transport boxes containing demolition debris to onsite storage. The system provides a safe way to transport the debris outside of the space-limited tented area, according to OREM.
“Removal of these hot cells is the first major demolition project associated with the environmental cleanup activities beginning to ramp up at ORNL,” said Susan Reid, UCOR project manager. “UCOR is proud to be part of this effort, working in collaboration with ORNL to remove unneeded facilities and facilitate the site’s expanding science missions.”