Crews remove reactor vessel; Oak Ridge lab deactivation project moves forward
First step before preparing the rest of the Oak Ridge research reactor for demolition
Frontier is the world’s fastest supercomputer at Oak Ridge National Lab
Frontier, the world’s largest supercomputer, is housed in the Oak Ridge Leadership Computing Facility at Oak Ridge National Laboratory.
Team members of the Oak Ridge Office of Environmental Management (OREM) contractor United Cleanup Oak Ridge (UCOR) have successfully lifted and removed the lower reactor vessel from the Oak Ridge Research Reactor, also known as Building 3042.
The accomplishment by the U.S. Department of Energy’s Office of Environmental Management marked a major advance for one of the largest decommissioning projects at Oak Ridge National Laboratory. The removal of the vessel is the first step before the rest of the facility is prepared for impending demolition.
Recently, workers used a 62-inch diamond wire saw to cut the final pieces holding the lower reactor vessel to the bottom of the reactor pool. They used a 20-ton overhead crane to lift the equipment and load it into a 32,000-pound containment vessel to transport it to another site for disposal.
“Removing the reactor vessel from the Oak Ridge Research Reactor facility was an incredibly complex task,” said Jim Daffron, ORNL portfolio project manager. “Thanks to tremendous planning and careful execution, workers were able to complete the job safely.”
UCOR dismantled the upper part of the reactor vessel last fall. Since then, teams have been focusing on filtering and draining the water in the reactor pool to access contaminated materials and prepare for the dismantling of the lower reactor vessel.
The high dose of radiation required strict safety measures, and that dose increased when thousands of gallons of pool water were pumped into tanks outside the plant, reducing the distance between the radioactive materials and the workers.
After the wastewater was safely drained, crews conducted sampling and characterization to ensure work areas remained safe for final tasks, including component removal.
“During the Pool Reactor rehabilitation and cleanup process, we faced numerous challenges together with our key partner, Energy Solutions, who shared their knowledge and experience and helped us resolve critical issues quickly and safely,” said Steven Reed, UCOR Oak Ridge Research Reactor Project Manager.
Workers removed 127,000 gallons of water and sediment to reach the lower part of the reactor vessel, which sat on the pool floor. They also removed the lead brick shielding in the basement that surrounded the pool. Twenty crew members loaded 157,000 contaminated bricks into containers.
Next Steps
The next steps to prepare the reactor for demolition include isolating and deactivating 1,800 meters of piping. Crews will also complete draining the pool water and encase the 7.5-meter-deep pool with a fixative to reduce contamination migration during demolition.
This is OREM’s latest project to help transform ORNL’s central campus, with cleanup efforts that eliminate hazards and make room for future research missions.
Carol Hendrycks is a member of UCOR’s communications team.
