Historic Markers Across Tennessee

X-10 Plant

Marker ID: THC 1F 40
Location: Roane County, Bethel Valley Road
County: Roane
Waymark: None


A Manhattan Project facility, the plutonium pilot plant was constructed in 1943 as a production model for the Hanford Engineering Works. The air-cooled graphite reactor "went critical," on November 4, 1943. The world's first radioactive isotope for medical use was produced here on August 2, 1946. The facility now serves as one of this country's national laboratories.