Inside the X-10 Graphite Reactor: a 24-foot cube of graphite

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

The X-10 Graphite Reactor at Oak Ridge, Tennessee — the Manhattan Project's pilot plant for plutonium — was, at heart, a 24-foot cube of graphite with uranium pushed through it by hand and air blown through it to keep it cool. A panel inside the building, now part of Manhattan Project National Historical Park, explains how it was built.

The reactor by the numbers

Loading and unloading

Operators slid fresh slugs into the channels by hand and centred them in the graphite with long rods. Spent slugs were pushed out the far side into a canal of water 20 feet deep; the water and the concrete kept radiation from escaping. Researchers worked at separate experimental faces behind heavy lead shields.

On the panel

A bird's-eye photograph of the five-storey, square reactor building with its low wings and two tall stacks; uranium's square from the periodic table; operators with a long rod at the loading face; four workers — three men and a woman — shifting a lead shield; and a cutaway drawing of the graphite cube, with small figures at the control panel and on the gantry behind it for scale.

Visiting

The reactor is inside the secure grounds of Oak Ridge National Laboratory and can be seen only on a guided tour.

Sources

Written from "Oak Ridge X-10: Graphite Reactor Design, Panel 1", National Park Service, Manhattan Project National Historical Park, describing a panel by the U.S. Department of Energy; both are works of the United States government in the public domain.