Uranium enrichment began in the United States as part of the World War II Manhattan Project to produce nuclear weapons. The first uranium enrichment operations were set up at what is now the Oak Ridge Nat’l. Laboratory (Tennessee) in 1942. In the 1950’s the U.S. government set up two additional enrichment plants, in Paducah in 1952 and in Piketon, Ohio.

The major technology used at Oak Ridge for the weapons program was gaseous diffusion. The Paducah and Piketon plants also were gaseous diffusion plants. USW and its predecessor unions have represented workers at all three sites from early on.