S50

S50, S-50, or S.50 may refer to:

S-50 (Manhattan Project)

S-50 was a Manhattan Project production facility which enriched uranium by liquid thermal diffusion; one of three Manhattan Project uranium enrichment plants at the Clinton Engineer Works in Oak Ridge, Tennessee.

The thermal diffusion process for uranium isotope separation, which had been developed by U.S. Navy scientists, was not one of the uranium enrichment technologies initially selected for use in the Army-led Manhattan Project. However, in June 1944, after reviewing progress of Philip Abelson's experiments on thermal diffusion at the Philadelphia Navy Yard, a team of Manhattan Project experts recommended that a thermal diffusion plant be built to augment production capacity from the electromagnetic separation process then operating at the Y-12 plant in Oak Ridge.

On June 18, 1944, Major General Leslie Groves contracted with the H.K. Ferguson Company of Cleveland, Ohio, to build the S-50 plant. He gave the company just 90 days (half the time optimistically estimated to be necessary) to complete the project, which included installation of 2,142 48-foot-tall (15 m) copper and nickel diffusion columns. The facility was located adjacent to the K-25 site, where the massive gaseous diffusion plant was under construction. With the help of creative shortcuts, such as using passenger trains to deliver some construction materials, Ferguson met its seemingly impossible deadline. On September 16, 1944, the S-50 enrichment plant began partial operation. Union Carbide was the operating contractor. Steam was obtained from the K-25 powerhouse. Initially, leaks limited production at S-50, but by January 1945 the facility began substantial production of uranium enriched to about 0.85% U-235. As of March 15, 1945, all 21 production "racks" were operating.