1943 at Oak Ridge: Building the X-10 Graphite Reactor

The exhibit panel at the X-10 Graphite Reactor. U.S. Department of Energy

An exhibit panel at the X-10 Graphite Reactor, now part of Manhattan Project National Historical Park, tells the story of 1943, the year it was built at Oak Ridge.

A new laboratory

The site was called Clinton Laboratories, code-named X-10, and run by the Monsanto Chemical Company. Arthur Compton and his assistant Richard Doan had headed the Metallurgical Laboratory at the University of Chicago; in 1943 Compton made Doan research director at Clinton Laboratories. Physicist Enrico Fermi, who had directed the design of Chicago Pile 1, directed the Graphite Reactor's design too.

Building it

Photographs on the panel show the reactor building wrapped in five levels of wooden scaffolding, and aerial views of the finished building among many others across the valley floor.

Going critical

Fermi and Compton supervised the loading of uranium fuel into the X-10 pile, whose loading face workers filled channel by channel, inserting rods. Calculations said 50 to 60 tons of uranium slugs would be needed before a self-sustaining fission reaction could start. After 30 tons were loaded, the control rod was pulled out and the neutron flux measured — and the team judged that the reactor would go critical before dawn during the next loading.

Visiting

The reactor stands on the secure grounds of Oak Ridge National Laboratory; visitors can see it only on guided tours.

Sources

Based on "Oak Ridge X-10: 1943- Graphite Reactor is Born," a description of an exhibit panel, National Park Service, Manhattan Project National Historical Park; a work of the United States government in the public domain.