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Licence: CC0 1.0 (public domain) · Adapted from www.nps.gov
In these publicationsManhattan Project National Historical Park
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
| Moderator | a 24-foot cube of stacked graphite blocks, which slowed neutrons to a speed uranium nuclei readily absorb |
| Fuel | natural uranium — 99.3% uranium-238, 0.7% uranium-235 — in gas-tight aluminium jackets |
| Fuel slugs | 1 inch by 4 inches, 24 to 54 per channel |
| Channels | 1,248 horizontal channels, of which only 800 held fuel |
| Fuel load | usually about 54 tons |
| Maximum power | 4,000 kilowatts — reachable safely only on cold days, because outside air cooled the reactor |
| Shielding | seven feet of concrete around the reactor |
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.
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About this page
Licence: CC0 1.0 (public domain) · Adapted from www.nps.gov
In these publicationsManhattan Project National Historical Park
