NBC Nightly News, June 28, 2011. Lisa Myers reports,

Pete Stockton, former Department of Energy official, says “the public should be concerned but not alarmed as a wildfire inches closer to a  nuclear weapons facility in Los Alamos, New Mexico.”

New Mexico fire managers scrambled Tuesday to reinforce crews battling a third day against an out-of-control blaze at the edge of one of the top U.S. nuclear weapons production centers.

The fire’s leading edge burned to within a few miles of a dump site where some 20,000 barrels of plutonium-contaminated waste, including clothing and equipment, is stored at the Los Alamos National Laboratory, fire officials said.

The town of Los Alamos, home to about 12,000 people, was evacuated Monday afternoon as a precaution.

The wildfire — which has burned 60,000 acres, or 93 square miles, in just two days — was as close as 50 feet from the Los Alamos National Laboratory grounds on Tuesday afternoon.

On Monday, a spot fire at the lab was quickly contained, and lab officials said no contamination was released.

Lab officials and fire managers said they’re confident the flames won’t reach key buildings or areas where radioactive waste is stored in barrels above ground.