Officials at the U.S. nuclear laboratory in Los Alamos, New Mexico, say a raging wildfire threatening the town is not likely to reach the facility.
Lab spokeswoman Lisa Rosendorf said that at this point, the risk of the Las Conchas blaze going onto lab property is less than 10 percent.
The lab and residents of Los Alamos were evacuated on Monday. Rosendorf said the facility remains closed, and officials have not said when it will reopen.
Workers have taken precautions to protect the lab, including conducting controlled burns and mowing excess brush.
Lab officials have said all nuclear and hazardous material, including waste stored on the complex, is safe. Radiation tests conducted by plane have revealed no contamination to the air as a result of the fire.
With more than 37,000 hectares already burned, the blaze was set to become the largest in New Mexico's history.
Some 1,000 firefighters have been working to tame the fire, but as of Thursday, it was only 3 percent contained. Federal fire officials say the blaze near Los Alamos is the biggest of a half-dozen wildfires active in the drought-stricken state of New Mexico.
Wildfires are also burning in the neighboring state of Arizona, where the Wallow fire has burned more than 200,000 hectares, but is now considered 95 percent contained.
Officials say large fires are burning in nine U.S. states, including the southern states of Texas, Georgia, and Florida.
Some information for this report was provided by AP, AFP and Reuters.