Though initially in secret, the graphite reactor at the X-10 facility in Oak Ridge proved to the world that plutonium could be created in a uranium reactor. Graphite reactors at Hanford and Oak Ridge were in operation throughout the Manhattan Project and in subsequent decades. The graphite reactor at Oak Ridge first produced electricity with nuclear power in 1948 and went on to create the world’s first radioisotopes for use in nuclear medicine. The B reactor at Hanford, the first industrial-scale nuclear reactor, produced plutonium used at the Trinity test in Alamagordo and in the atomic bomb dropped on Nagasaki. It is on the National Register of Historic Places as a Registered National Historic Landmark.