Feynman was sent to which Tennessee Manhattan Project site for uranium safety work?

Feynman was sent to the Clinton Engineer Works in Tennessee for uranium safety work during the Manhattan Project.

The Clinton Engineer Works, located near Oak Ridge, housed major uranium-enrichment facilities, including the Y-12 electromagnetic separation plant. Feynman’s assignment came after his work at Los Alamos, where he had helped with theoretical calculations and criticality-related problems.

At Oak Ridge, Feynman helped engineers develop procedures for storing enriched uranium safely. A central danger was criticality: if enough fissile material came together in the wrong arrangement, a self-sustaining nuclear chain reaction could begin. Water was especially important because it can act as a neutron moderator, making a criticality accident more likely under certain conditions.

A common mix-up is confusing the Clinton Engineer Works with Los Alamos, where the bomb designs were developed, or with the Trinity Site, where the first nuclear test occurred. Hanford was another Manhattan Project location, but it focused mainly on producing plutonium rather than the Oak Ridge uranium-enrichment work described here.