Demolition Preparations Progress at Alpha-4

A full view of the 500,000-square-foot Alpha-4 facility, a Manhattan Project facility slated for demolition in Oak Ridge.

Source: EM Update | Vol. 13, Issue 21 | June 1, 2021

EM’s cleanup at the Y-12 National Security Complex continues to expand as workers ready one of the site’s largest high-risk contaminated facilities for demolition.

Oak Ridge has hundreds of excess, contaminated facilities and contains the largest inventory of high-risk structures in the DOE complex. This latest project, and others like it underway by EM, are addressing these hazards and enabling the transformation and modernization of important research and national security sites.

EM contractor UCOR is leading cleanup efforts at the massive four-story Alpha-4 building, which spans more than 500,000 square feet and covers a 13-acre area. This project is challenging not only due to the facility’s size, but also its mercury contamination.

“We are excited to continue moving forward with this major cleanup project,” said Brian Henry, Y-12 portfolio federal project director for DOE’s Oak Ridge Office of EM. “There are a lot of steps involved in addressing a massive building in its deteriorated condition, but each step moves us closer to being able to eliminate a hazard and significantly alter the landscape in the heart of Y-12.”

A view of the side of the Alpha-4 facility showing one of three Column Exchange processes to be demolished.

The facility was used for uranium separation from 1944 to 1945. A decade later, workers finished installing Column Exchange (COLEX) equipment on the west, east, and south sides of Alpha-4 for lithium separation, a process requiring large amounts of mercury. A significant amount of mercury was lost into the equipment, building, and surrounding soils during those operations. Mercury cleanup is one of EM’s top priorities at Y-12.

Although employees drained the majority of materials from the equipment when operations ended there in the 1960s, recoverable amounts of mercury remained in aging lines and equipment that had rusted and deteriorated over the decades. In recent years, UCOR crews retrieved more than 10,000 pounds of mercury from the COLEX equipment and demolished the equipment on the west side of Alpha-4.

Now, work is underway to deactivate the COLEX equipment on the east side of Alpha-4, and removal of the equipment from its south side will follow. Planning is also taking place for deactivation work required in the facility.

Two pivotal projects are already underway that will enable removal of Alpha-4. The first is construction of the Mercury Treatment Facility. Scheduled to be operational in 2025, the facility will capture and treat mercury releases entering a nearby creek caused by crews and big machinery tearing down Alpha-4 and other large, mercury-contaminated buildings in the area. The facility is designed to treat up to 3,000 gallons of water per minute and includes a 2-million-gallon storage tank to collect stormwater.

Other critical work is the National Nuclear Security Administration’s West End Protected Area Reduction Project, also slated for completion in 2025. That effort is rerouting portions of the high-security area at Y-12 around Alpha-4 and the other mercury-contaminated buildings, allowing enhanced access for cleanup crews and cutting cleanup costs by more than 40 percent.

While cleanup activities are in the early stages at Alpha-4, other crews are deactivating several other 1940s-era buildings at Y-12, including Alpha-2, Beta-1, the Old Steam Plant, and the Old Criticality Experiment Laboratory.

The extensive Y-12 cleanup effort is happening simultaneously with other cleanup projects underway at Oak Ridge National Laboratory, where workers are addressing 16 inactive research reactor and isotope facilities.