A wildfire burning near the desert birthplace of the atomic bomb advanced on the Los Alamos laboratory and thousands of outdoor drums of plutonium-contaminated waste Tuesday as authorities stepped up efforts to protect the site from flames and monitor the air for radiation.
Officials at the nation's premier nuclear weapons lab gave assurances that dangerous materials were safely stored and capable of withstanding flames from the 93-square-mile (240 square kilometer) fire, which as of midday was as close as 50 feet (15 meters) from the grounds.
A small patch of land on the laboratory grounds caught fire Monday before firefighters quickly put it out. Teams were on high alert to pounce on any new blazes and spent the day removing brush and low-hanging tree limbs from the lab's perimeter.
The fire has forced the evacuation of the entire city of Los Alamos, population 11,000, cast giant plumes of smoke over the region and raised fears among nuclear watchdogs that it will reach as many as 30,000 55-gallon (208-liter) drums of plutonium-contaminated waste.
"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 Concerned Citizens for Nuclear Safety, an anti-nuclear 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 said there was very little risk of the fire reaching the drums of low-level nuclear waste, since the flames would have to jump through canyons first. Officials also stood ready to coat the drums with fire-resistant foam if the blaze got too close.
Lab spokeswoman Lisa Rosendorf said the drums contain Cold War-era waste that the lab sends away in weekly shipments for storage. She said the drums were on a paved area with few trees nearby. 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.
Los Alamos employs about 15,000 people, covers more than 36 square miles (93 square kilometers), includes about 2,000 buildings at nearly four dozen sites and plays a vital role in the nation's nuclear program.
In the decades since, the lab has evolved into a major scientific and nuclear research facility. It stockpiles aging atomic materials, tests warheads, produces triggers for nuclear weapons and operates supercomputers and particle accelerators.
It also conducts research on such things as climate change and the development of a scanner for airports to detect explosive liquids. The lab's supercomputer was used in designing an HIV vaccine.
Lab officials gave assurances that buildings housing key research and scientific facilities were safe because they have been fireproofed over the years, especially since a 2000 blaze that raged through the area but caused no damage to the lab. Trees and brush were thinned over the past several years, and key buildings were surrounded with gravel to keep flames at bay.
Teams from the National Nuclear Security Administration's Radiological Assistance Program were headed to the scene to help assess any hazards.
Lab officials said they were closely watching at least 60 air monitors for radiation and other hazards. The New Mexico Environment Department was also monitoring the air, and Udall said he asked the U.S. Environmental Protection Agency to do the same.
The lab has been shut down all week because of the fire, but authorities said the disruption is unlikely to affect any key experiments. The lab will be closed at least through Wednesday.
The wildfire has destroyed 30 structures near Los Alamos, stirring memories of a devastating blaze in May 2000 that wrecked hundreds of homes and other buildings. About 12,500 residents in and around Los Alamos have been evacuated, an orderly exit that didn't even cause a traffic accident.