"Plan of Layer 32"
By an unknown engineer, 1942
Pencil on photo-reproductive print on paper
22 1/2" x 16 1/2"
National Archives and Records Administration -- Great Lakes Region (Chicago), Records of the Atomic Energy Commission

World's First Nuclear Reactor
Eight months after the United States entered World War II, the Federal Government launched the Manhattan Project, an all-out, highly secret effort to build an atomic bomb. The task was to translate the vast energy released by nuclear fission into a weapon of unprecedented power. On December 2, 1942, a group of physicists working under top-secret conditions in a laboratory at the University of Chicago took a crucial step toward this goal; they created the world's first controlled, self-sustaining nuclear reaction. The drawing displayed here depicts the construction of the world's first nuclear reactor, constructed of graphite and uranium bricks and wooden timbers in the precise arrangement necessary to start and regulate a nuclear chain reaction. It also shows the placement of cadmium rods into the reactor in order to prevent the reaction from accelerating out of control with catastrophic results.