Oak Ridge Reactor to be Dismantled for Further Transportation and Disposal
At the Oak Ridge National Laboratory (ORNL), workers from the Unified Cleanup Oak RIdge LLS (UCOR) dismantled and placed the lower section of the research reactor vessel in a container for further transportation and disposal. The reactor, known as Building 3042, part of the Manhattan Project, had been irradiating and producing isotopes since 1958 and was permanently shut down in July 1987.
Reactor 3042 during its operation, 1967. Four working levels for research and production of isotopes. Photo: UCOR
Employees working from the first level and the pool, 1983. The “blue glow” of the reactor core is Cherenkov radiation, which is produced by neutrons and protons whose rate is greater than the phase speed of light in the environment. Photo: UCOR
After the upper part of the reactor vessel was dismantled in the fall of 2023, UCOR specialists focused on filtering and draining the water from the reactor pool to get to the irradiated materials and prepare for the dismantling of the lower part of the vessel.
As the water was pumped from the pool to the tanks, the buffer between radioactive materials and workers decreased and the exposure dose increased, requiring strict safety measures.
Workers dismantling the upper part of the reactor. The green light at the bottom is regular lighting, used to improve the accuracy of the fixture. Photo: U.S. Department of Energy
Workers removed 480 cubic meters of water and sludge to get to the bottom of the reactor vessel, which was at the bottom of the pool. The lead brick lining that surrounded the pool was removed, and 157,000 contaminated bricks were loaded into containers.
Using a 1.8-meter diamond rope saw, the last beams supporting the lower vessel part at the bottom of the reactor pool were cut off. A 20-ton overhead crane lifted and loaded the equipment into a shielded container for off-site disposal.
Crews used a diamond saw to cut the last parts that held the lower vessel part in the bottom of the reactor pool. This photo shows the last segment of the reactor being lifted out of the pool area. Photo: U.S. Department of Energy
The dismantling of the reactor vessel is the first step in preparing the Building 3042 facility for demolition. Next steps will include isolating and decontaminating 1,830 meters of piping. Crews will also finish draining the pool and encapsulating the 7.5-meter-deep pool with a fixative to reduce contamination migration during dismantling.
According to the U.S. Department of Energy
The reactor vessel is loaded into a protective shipping container for transportation and disposal offsite. Photo: U.S. Department of Energy