Calutron operators at their panels, in the Y-12 plant at Oak Ridge during World War...

The calutrons were used to refine uranium ore into fissile material. During the Manhattan Project effort to construct an atomic explosive, workers toiled in secrecy, with no idea to what end their labors were directed. Gladys Owens, the woman seated in the foreground, did not realize what she had been doing until seeing this photo in a public tour of the facility fifty years later The town of Oak Ridge was established by the Army Corps of Engineers as part of the Clinton Engineer Works in 1942 on isolated farm land as part of the Manhattan Project. The site was chosen for the X-10 Graphite Reactor, used to show that plutonium can be extracted from enriched uranium.