As the Department of Energy’s motivated cleanup team tries to stabilize some of the worst of the worst situations at excess facilities at the Oak Ridge Reservation in Tennessee, a focal point appears to be the Alpha-4 facility located inside the high-security “Protected Area” of the Y-12 nuclear weapons plant.
Besides dealing with a basement loaded full of contaminated water, DOE cleanup manager Sue Cange expressed her concerns about the mercury-contaminated COLEX equipment that was used decades ago during Cold War processing of lithium for hydrogen bombs.
Alpha-4 is the only Y-12 building that still has its COLEX processing system intact inside the facility. But a bigger concern in the near-term, $28 million work to attack risky sites at Oak Ridge is the rusty old equipment outside the building and exposed to the elements. Mercury is “holed up” inside the COLEX equipment, the DOE official said.
“We will know more about it once we do the characterization,” Cange said.
The near-term term concern is with the COLEX equipment that’s located outside the Alpha-4 building because it’s rusty and exposed to environment. Alpha-4 was one of the original uranium-enrichment facilities built during World War II work on first atomic bombs, but it was converted — like some other Y-12 facilities — during the Cold War to other uses. In this case, it was used to process lithium, which required heavy use of mercury. There was COLEX equipment both inside and outside Alpha-4.
Alpha-4 is located inside the high-security Perimeter Intrusion Detection and Assessment System (PIDAS) at the Oak Ridge national security site.
“I will say we’re very concerned with the structural integrity of the equipment,” Cange said. “It’s very old and rusted through, and it is located near the PIDAS fence. So it’s not only in our best interest from a contaminant perspective, but it’s also in the best interest of the NNSA to remove that.”
A big problem at Alpha-4 is the water leaking through its roof. Asked how much water has accumulated in the building’s basement, Cange replied, “The volume of the water fluctuates because of the season and the amount of rainfall.”
A problem is that the basement’s water is intermingling with the local groundwater, and there’s lots of residual mercury in Alpha-4. Three years ago, DOE estimated 151,000 pounds of residual mercury remained inside Alpha-4 systems, and there are concerns about the mercury’s mobility, especially if it reaches the groundwater.
