The US Department of Energy’s Savannah River Site in South Carolina declared a Site Area Emergency on Wednesday after a fire at the Savannah River National Laboratory.
The emergency was declared at 5.39 pm local time (2139 GMT), according to a statement from the site near Aiken.
“A fire was reported at the Savannah River National Laboratory but has since been extinguished. No contamination has been reported outside the affected facility,” the site said on X.
Earlier, the site said an event was under way that had “triggered emergency response activities”.
The Federal Aviation Administration issued a temporary flight restriction, citing a US government “nuclear incident” at the site.
The cause of the fire, the type and quantity of any material released, and whether anyone was injured remain unknown.
The Savannah River Site is a major installation in the US weapons complex that has supported the country’s strategic deterrence mission for more than 75 years, according to its website.
