ORNL crews remove reactor as part of a major deactivation project

Team members at Oak Ridge National Laboratory achieved a milestone with the removal of a lower reactor vessel, according to a U.S. Department of Energy news release.

Team members with the Oak Ridge Office of Environmental Management (OREM) contractor UCOR successfully lifted and removed the lower reactor vessel from the Oak Ridge Research Reactor, also known as Building 3042.

"Removing the reactor vessel from the Oak Ridge Research Reactor facility has been an incredibly complex task," said Jim Daffron, ORNL portfolio project director. "Through an immense amount of planning and careful execution, workers were successful and completed the work safely."

A closer look: Workers used a 72-inch diamond wire saw to cut the final pieces holding the lower reactor vessel in place at the bottom of the reactor pool. The team then used a 20-ton overhead crane to lift the equipment and load it into a 32,000-pound protective cask to ship it for disposal off-site.

UCOR removed the top portion of the reactor vessel last fall. Since then, crews have focused on filtering and draining the reactor pool water to reach irradiated materials and prepare for the lower reactor vessel removal.

This is one of the largest deactivation projects at ORNL, and removing the vessel is the first step before preparing the remainder of the facility for demolition.

Staying safe: The team employed rigorous safety measures due to high radiation dose rates, which increased as the crew pumped 127,000 gallons of pool water into outdoor tanks-lowering the buffer between radioactive materials and workers.

With the wastewater safely drained, employees performed sampling and characterizing to ensure the work areas remained safe for final tasks, including removal of components.

"We faced various challenges throughout the pool reactor remediation and cleanup process with our key partner, EnergySolutions, who provided their knowledge and expertise in collaboration, helping us resolve critical issues quickly and safely," said Steven Reed, UCOR Oak Ridge Research Reactor project manager.

What's next: Crews will finish draining the pool water and encapsulate the 25-foot-deep pool with a fixative to reduce contamination migration during demolition. Before the reactor can be demolished, the team will isolate and deactivate 6,000 feet of piping.

The project is helping transform ORNL's central campus and prepares the site for future research missions.