With both the K-25 and Y-12 plants suffering setbacks in the spring of 1944, Oppenheimer urged Groves to approve the construction of a thermal diffusion plant. The U.S. Navy had researched this method for three years and was already building a pilot plant of 100 columns in Philadelphia. After reviewing Oppenheimer’s suggestions, Groves decided in late June 1944 to approve construction for what would become the S-50 Thermal Diffusion Plant.
General Leslie Groves
The K-25 Plant in Oak Ridge used the gaseous diffusion process to enrich uranium.
Gaseous Diffusion Process
The K-25 plant was an enormously ambitious and risky undertaking. A mile-long, U-shaped building, the K-25 plant was the world’s largest roofed building at the time. British scientists working on the “tube alloy,” code for the atomic bomb project, first advocated the gaseous diffusion method in March 1941. Because of the Nazi bombing of England, any production plants had to be located elsewhere.
In 1942, General Leslie Groves approved Oak Ridge, Tennessee, as the site for the pilot plutonium plant and the uranium enrichment plant. Manhattan Project engineers had to quickly build a town to accommodate 30,000 workers--as well as build the enormously complex plants.