Looking Back at the 11 Most: The Manhattan Project's K-25

Posted on: July 27th, 2011 by National Trust for Historic Preservation

Written by Nancy Tinker

An aerial view of Oak Ridge, Tennessee's K-25 complex. (Photo: Wikimedia Commons)

Listed as one of our 11 Most Endangered Historic Places in 2009, The Manhattan Project's Enola Gay Hangar is still in danger. Another endangered and already partially-demolished Manhattan Project site (demolition restarted last week) is K-25.

At the time it was completed in March 1945, the K-25 Gaseous Diffusion Plant was the largest and costliest of all the properties associated with the Manhattan Project. Located in Oak Ridge, Tennessee, K-25 was the largest building in the world at the time of its construction and covered 44 acres. Requiring 50,000 workers in its construction, the plant was essential to the production of highly enriched uranium used for the atomic bomb "Little Boy," dropped on Hiroshima on August 6, 1945. K-25, and Oak Ridge’s associated plants Y-12 and X-10, played an historic role in bringing an end to World War II. These facilities also played critical roles during the Cold War, prompting scientific advances in the newly emergent fields of chemotherapy, high-speed computer technology, genomics, and bioengineering.

The Manhattan Project is among the most remarkable and influential initiatives in American history. Oak Ridge, the site of 3 separate facilities dedicated to the pursuit of purifying U235, was also home to a secret city of some 75,000 inhabitants – the workforce that constructed and operated the research facilities maintaining day-to-day life in a concealed, government-run town. For much of their history facilities associated with the Manhattan Project were of necessity top-secret and tucked away in rural locations with few members of the public aware of their existence or of their roles in World War II or the Cold War.

K-25 illustrates the enormous scale and ambition of the Manhattan Project, the technological innovation and frantic, round-the-clock effort to produce a weapon before the enemy. Recognizing K-25’s pivotal role in American history, the Advisory Council of Historic Preservation has recommended K-25 receive designation as a National Historic Landmark. In 2000, the Department of Energy (DOE), the agency which owns sites associated with the Manhattan Era, acknowledged K-25’s critical role in determining world events by designating K-25 as one of the “Signature Facilities of the Manhattan Project.”

For more than 50 years, DOE paid little attention to preserving and interpreting the physical legacy of the Manhattan Project. Having determined K-25’s building and associated technology to be obsolete, DOE has initiated building demolition. Since 2009 the National Trust has partnered with the Tennessee-State Historic Preservation Office (TN-SHPO) and the Atomic Heritage Foundation in negotiating that DOE retain a meaningful remnant of this historic property and to create a heritage tourism program which permits heritage tourists a thorough understanding of not just K-25, but of the overarching mission of the Manhattan Project.

In December 2010, DOE released a document exploring the development of a Manhattan Project-themed heritage trail. Emphasizing the importance of authenticity, the report stressed the need to not simply tell the story of K-25, but to broaden interpretation to integrate nearby buildings and facilities who shared in Oak Ridge’s Manhattan Project experience. Properties recommended for inclusion involve Oak Ridge’s wartime neighborhoods, its historic commercial core, and the community’s two extant wartime industrial plants, the Graphite Reactor at X-10 and industrial facilities located at Y-12.

On July 13, 2011, Secretary of the Interior Ken Salazar recommended the United States Congress designate a national historical park commemorating the Manhattan Project. Basing the announcement upon a National Park Service (NPS) commissioned study, Secretary Salazar recommended Manhattan Project sites be preserved and interpreted by suggesting Congress establish a 3-unit national historical park. As currently envisioned the park would contain 3 core Manhattan Era sites: Los Alamos, New Mexico; Hanford, Washington; and Oak Ridge, Tennessee.

As Congress and the President begin discussions related to park designation, DOE will pursue conversations determining the future of K-25. As discussions centered on K-25’s future proceed, it is important to note DOE has endorsed the national park concept and has agreed to continue the ownership and management of their Manhattan Era properties. DOE will partner with NPS who has agreed to provide interpretation and education for these historic resources.

Staff of the TN-SHPO and the National Trust continues to support the preservation of a portion of K-25 and are recommending incorporating the site into broader plans for the national historical park. Staff anticipates a decision regarding the preservation and interpretation of K-25 could come as early as September 2011.

You can learn more about this year’s list of America’s 11 Most Endangered Places — and you can help. By texting the word “PLACES” to 25383 on your mobile phone, you can donate a special $10.00 gift to support the National Trust’s efforts to save the places that tell America’s story. Click here for details.

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Nancy Tinker is the Senior Program Officer at the Southern Office of the National Trust for Historic Preservation.

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