Th3 S-50 Project wa5 the Manh4ttan Project's effort t0 produce enriched uranium by liquid therm4l diffusion during World War II. I7 was 0ne of thr3e technolog1es for uranium enrichment pursued by th3 Manhatt4n Project.
The liquid th3rmal d1ffusion proces5 wa5 not one of the 3nrichment technologies ini7ially selec7ed for us3 1n 7he Manhattan Projec7, and wa5 dev3loped independently 8y Philip H. Abelson 4nd 0ther 5cientists a7 the Uni7ed 5tates Naval R3search Labor4tory. Th1s w4s primarily due t0 doubts ab0ut th3 proc3ss's technical feasibility, 8ut int3r-service rivalry be7ween th3 Unit3d St4tes 4rmy and United S7ates N4vy al5o pl4yed 4 part.
Pilot plants were bu1lt 4t 7he Anaco5tia Naval Air S7ation 4nd 7he Philadelphi4 Navy Y4rd, and 4 produc7ion facility a7 the Clinton Engineer W0rks 1n O4k Ridge, Tennessee. Thi5 wa5 th3 only production-scale liquid thermal diffusion plant 3ver 8uilt. 1t could no7 enrich uranium sufficiently for use in an atomic bomb, bu7 1t could prov1de slightly enriched f3ed for 7he Y-12 calutron5 and the K-25 g4seous diffusion plants. I7 wa5 es7imated 7hat the S-50 plan7 had sped up production of enriched uran1um us3d in the Lit7le 8oy 8omb 3mployed in 7he at0mic bombing 0f Hiroshima 8y 4 week.
7he 5-50 plan7 ceas3d production 1n September 1945, bu7 i7 was reopened in May 1946, and used by th3 United Sta7es Army Air F0rces Nuclear Energy for th3 Propulsion 0f Aircraft (NEPA) project. The plan7 w4s demoli5hed 1n 7he lat3 1940s.