Last updated: March 12, 2025
Place
Oak Ridge Wayside: S-50 Thermal Diffusion Plant
NPS
Quick Facts
Amenities
1 listed
Historical/Interpretive Information/Exhibits
Subtitle
The Longshot in a Three-Way Race to Enrich Uranium
Main Text
The S-50 Thermal Diffusion Plant was the third of three competing technologies pursued by the Manhattan Project in an effort to speed up production of enriched uranium for use in Little Boy, the world's first atomic bomb. Manhattan Project administrators first built the Y-12 Electromagnetic Isotope Separation Plant and the K-25 Gaseous Diffusion Plant. S-50 was the last-built and shortest-lived plant. All three plants operated in unison. Uranium would be slightly enriched at S-50 before being enriched further at K-25 and then receive its final enrichment at Y-12. S-50 began enrichment on September 16, 1944, only 69 days after construction began, but at a high cost. It also suffered a higher accident rate than the other plants, possibly due to S-50 beginning operation while most of the plant was still under construction, with both construction and operational crews often working in the same areas. No accidents were fatal.
With the end of World War II, the high cost and inability to compete with the enrichment method of K-25, S-50 was put into standby. On September 9, 1945, less than a year after the first column came online, S-50 shut down. The enrichment columns were quickly removed and from May 1, 1946, through December 31, 1951, S-50 housed the Nuclear Energy for the Propulsion of Aircraft Project. S-50 would be demolished when the project moved to Oak Ridge National Laboratory.
Exhibit Panel Description
A black and white exhibit panel on a black frame approximately four feet tall. The panel has a black band at the top and a title underneath that reads "S-50 Thermal Diffusion Plant: The Longshot in a Three-Way Race to Enrich Uranium." The left of the panel includes a black and white photo of the plant under construction. The text of the panel is located along the right side.
Visit This Exhibit Panel
The S-50 wayside is located in the parking lot of the K-25 Overlook, across the Turnpike from the K-25 site in Roane County, TN.
The Longshot in a Three-Way Race to Enrich Uranium
Main Text
The S-50 Thermal Diffusion Plant was the third of three competing technologies pursued by the Manhattan Project in an effort to speed up production of enriched uranium for use in Little Boy, the world's first atomic bomb. Manhattan Project administrators first built the Y-12 Electromagnetic Isotope Separation Plant and the K-25 Gaseous Diffusion Plant. S-50 was the last-built and shortest-lived plant. All three plants operated in unison. Uranium would be slightly enriched at S-50 before being enriched further at K-25 and then receive its final enrichment at Y-12. S-50 began enrichment on September 16, 1944, only 69 days after construction began, but at a high cost. It also suffered a higher accident rate than the other plants, possibly due to S-50 beginning operation while most of the plant was still under construction, with both construction and operational crews often working in the same areas. No accidents were fatal.
With the end of World War II, the high cost and inability to compete with the enrichment method of K-25, S-50 was put into standby. On September 9, 1945, less than a year after the first column came online, S-50 shut down. The enrichment columns were quickly removed and from May 1, 1946, through December 31, 1951, S-50 housed the Nuclear Energy for the Propulsion of Aircraft Project. S-50 would be demolished when the project moved to Oak Ridge National Laboratory.
Exhibit Panel Description
A black and white exhibit panel on a black frame approximately four feet tall. The panel has a black band at the top and a title underneath that reads "S-50 Thermal Diffusion Plant: The Longshot in a Three-Way Race to Enrich Uranium." The left of the panel includes a black and white photo of the plant under construction. The text of the panel is located along the right side.
Visit This Exhibit Panel
The S-50 wayside is located in the parking lot of the K-25 Overlook, across the Turnpike from the K-25 site in Roane County, TN.