Weekly 150: The Manhattan Project

The four production facility sites were located in valleys away from the town. Site managers believed the valleys provided additional security along with containment in case of accidental explosions. The Y-12 area, home of the electromagnetic plant, was closest to Oak Ridge, one ridge away to the south. Farther to the south and west lay both the X-10 area, which contained the experimental plutonium pile and separation facilities, and K-25, the site of the gaseous diffusion plant and later the S-50 thermal diffusion plant.