K-25 viewing platform takes shape at Oak Ridge
Crews are making significant progress on the construction of the K-25 viewing platform at the Oak Ridge Reservation in Tennessee, the Department of Energy’s Office of Environmental Management announced on August 20. When completed next year, the elevated platform will offer a sweeping panoramic view of the massive 44-acre footprint of the K-25 Building, which once produced enriched uranium used in the weaponry that ended World War II.
A rendering of the K-25 Viewing Platform, scheduled to open to the public next summer. (Image: DOE)
The K-25 Building was the largest structure in the world when it was built in 1944 as part of the Manhattan Project. Later renamed the Oak Ridge Gaseous Diffusion Plant, the site expanded with new buildings constructed to produce enriched uranium for defense and commercial purposes until operations ended in 1985. The site was shut down in 1987.
Demolition of the K-25 Building began in 2008 and took five years to complete. The DOE’s Oak Ridge Office of Environmental Management (OREM) and its cleanup contractor UCOR carried out the decommissioning work. Additionally, they completed all other demolition at the plant site in 2020 and finished all soil remediation required on the K-25 footprint this summer.
The view: From the platform, visitors will have a complete view of the U-shaped K-25 footprint through 10-foot-tall wraparound glass windows.
Plans also involve installing visual indicators at each corner of the footprint, delineating the height and dimensions of the structure that once stood there to help visitors understand its immensity. Larger than the Pentagon, the four-story K-25 Building measured half a mile by 1,000 feet.
“The K-25 viewing platform will provide engaging displays that help visitors see and comprehend the full scale and magnitude of the former Manhattan Project and Cold War–era site,” said Steve Cooke, OREM’s project manager overseeing historic preservation. “This understanding will lead to a deeper appreciation of what previous generations accomplished here.”
The construction: Through an interagency agreement signed in 2022, OREM provided funding for the project, while the U.S. Army Corps of Engineers is overseeing construction. USACE awarded construction company Geiger Brothers a $9.9 million contract to build the platform in March 2023.
UCOR and subcontractor Smee + Busby Architects designed the platform. They also are providing engineering support during construction.
The facility is taking shape with Geiger Brothers finishing the concrete slab and erecting the structural steel framework. Construction is expected to be complete next spring, and the platform is set to open in summer 2025 after exhibits are installed inside.
Commemorating the history: Construction of the K-25 viewing platform is one of the final components of a multiproject agreement OREM signed in 2012 to commemorate the history of the former Oak Ridge Gaseous Diffusion Plant. OREM completed the other elements in previous years, including constructing the K-25 History Center and preserving the historic Alexander Inn.
The K-25 Building footprint is within the Manhattan Project National Historical Park, a unit of the National Park Service that also includes Los Alamos, N.M., and Hanford, Wash.
