Idaho wildfire burns near top U.S. nuclear research lab

July 24 (UPI) -- A wildfire in Idaho has forced one of the United States' top nuclear research labs to cut back personnel Wednesday, as the flames burned near the facility.

The Sheep Fire has so far burned about 90,000 acres near the Idaho National Laboratory, officials said Wednesday. The laboratory's facilities have been preparing for a possible loss of power and a shift to backup generators. The site's main gate is closed to non-emergency vehicles.

The facility, which is owned by the U.S. Department of Energy, is located in Idaho Falls.

The Bureau of Land Management said the fire has burned about 10,000 acres on lab grounds but has not yet threatened any structures.

"The public has not been threatened at all," Juan Alvarez, the lab's chief operations officer, told reporters Tuesday. "Fires this time of the year is something that we expect and prepare for."

Officials said lightning caused the fire Monday and the flames spread quickly to 90,000 acres by Tuesday. Winds helped spread the blaze. The fire slowed after more lightning overnight Monday.

BLM official Joel Gosswiller said he was unsure how much of the fire has been contained.