Historic Markers Across Tennessee

Y-12 – The Calutron Plant

Marker ID:  
Location: Alvin K. Bissell Park, at the intersection of Oak Ridge Turnpike (Tennessee Route 95) and South Tulane Ave, Oak Ridge, TN
County: Anderson
Coordinates: N 36° 0.819    W 084° 15.473
  36.01365    -84.25788333
Style: Mounted **
Waymark: None


Y-12 – The Calutron Plant

The top priority of the secret wartime Oak Ridge project was the Y-12 plant. That was the code name given to the process considered the best bet for separating weapon-grade uranium-235 (U-235) from U-238. This isotope separation process was the brainchild of Ernest O. Lawrence and his team at the University of California. The complex machines used at Y-12 were called “calutrons”, for California University cyclotrons. The architect-engineer for this first-of-its-kind plant was Stone & Webster Engineering of Boston. The plant’s wartime cost was $478 million. Construction of Y-12, which began in February 1943, required more than 10,000 construction workers and 14,700 tons of silver, valued at $300 million. Silver ingots were borrowed from U.S. Treasury vaults to make thousands of calutron electromagnets because normally used copper was urgently needed for other war uses. The plant operator was Tennessee Eastman Corp. of Kingsport. Frederick Conklin was plant manager. Ph. D. physicists were at first thought necessary to run the complex calutrons, but Eastman found that local women could be trained to outperform the scientists. The chemical recovery of the calutron project required tremendous effort. In May 1945 Y-12 had 22,400 employees. Despite the formidable technical problems of this brand new process, Y-12 succeeded in its wartime mission of producing the vital U-235 needed, enabling Los Alamos to build the first atomic bomb that helped bring World War II to an end. By the close of 1946, K-25 had taken over the U-235 production task, and about 20,000 Y-12 employees had left. In 1947 a new and equally vital nuclear defense mission was undertaken and has been successfully managed by Y-12 for the past half century.

Erected in Honor of the Scientists, Engineers, Managers, and Support Staffs Who Designed, Constructed, and Operated this Vital Facility of the Manhattan Project.


More information:
Wikipedia - Oak Ridge, Tennessee
Wikipedia - Manhattan Project
Wikipedia - Manhattan Project National Historical Park
US History for Kids - Manhattan Project Timeline
Secret City Commemorative Walk