The Texas Pantex factory, located 34 km from Amarillo, was forced to shut down its activities as the flames approached.
It built a fire barrier to protect its facilities.
“Operations at the plant have been suspended until further notice.
All weapons and special materials are safe and unaffected,” claimed a message posted on X by the company.
This plant assembles the U.S. nuclear arsenal, tests special nuclear materials, and manufactures powerful explosives.
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After a night of tension, the factory announced that it would be able to resume normal activity this Wednesday.
Earlier, the Texas A&M Forest Service announced that 25 of 31 wildfires in the state were now under control, but noted that the largest of them remains out of control, having devastated more than 1,200 km2.
Several cities, some as far as 100 miles from Amarillo, have issued evacuation orders, closed roads and ordered citizens to shelter at home or in public buildings.