LOS ALAMOS, N.M. — After a quiet morning, firefighters protecting this town and the nation's largest nuclear lab hoped the same would be true for the rest of Tuesday.
Calling it a "make or break day," officials said no additional structures had been lost but noted that the massive fire could make a run through two canyons.
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.
For the stored waste, officials say a last resort would include spraying foam on the barrels to ensure they aren't damaged by fire.
Teams from the National Nuclear Security Administration's Radiological Assistance Program were headed to the scene to help assess any nuclear or radiological hazards, said Kevin Smith, Los Alamos Site Office manager.
"The ... teams' work will provide another level of assurance that the community is safe from potential radiological releases as the fire progresses," Smith said in a statement.
The lab will be closed through at least Wednesday, with only essential employees permitted back onto laboratory property.
The wildfire has destroyed 30 structures south and west of Los Alamos, for many stirring memories of a devastating blaze in May 2000 that destroyed hundreds of homes and buildings in town.
Flames were just across the road from the southern edge of the famed lab, where scientists developed the first atomic bomb during World War II. The facility cut natural gas to some areas as a precaution.
The lab, which employs about 15,000 people, covers more than 36 square miles and includes about 2,000 buildings at nearly four dozen sites. They include research facilities, as well as waste disposal sites. Some facilities, including the administration building, are in the community of Los Alamos, while others are several miles away from the town.
The spot fire scorched a section known as Tech Area 49, which was used in the early 1960s for a series of underground tests with high explosives and radioactive materials.
Lab spokesman Kevin Roark said environmental specialists were monitoring air quality, but the main concern was smoke.
The anti-nuclear watchdog group Concerned Citizens for Nuclear Safety said the fire appeared to be about 3.5 miles from a dumpsite where as many as 30,000 55-gallon drums of plutonium-contaminated waste were stored in fabric tents above ground. The group said the drums were awaiting transport to a dump site in southern New Mexico.
"The concern is that these drums will get so hot that they'll burst. That would put this toxic material into the plume. It's a concern for everybody," said Joni Arends, executive director of the group.
Arends' group also worried that the fire could stir up nuclear-contaminated soil on lab property where experiments were conducted years ago. Over the years, burrowing animals have brought that contamination to the surface, she said.
Lab officials at first declined to confirm that such drums were on the property but, in a statement early Tuesday, lab spokeswoman Lisa Rosendorf said such drums are stored in a section of the complex known as Area G. She said the drums contain cleanup from Cold War-era waste that the lab sends away in weekly shipments to the Waste Isolation Pilot Plant.
She said the drums were on a paved area with few trees nearby and would be safe even if a fire reached the storage area.
As of midday Tuesday, the flames were about two miles away from the material.
"These drums are designed to a safety standard that would withstand a wildland fire worse than this one," Rosendorf said.The wildfire, which began Sunday, stirred memories of a devastating blaze in May 2000 that