LOS ALAMOS, N.M. (AP) - The government sent a plane equipped with radiation monitors over the Los Alamos nuclear laboratory Wednesday as a 110-square-mile wildfire burned at its doorstep, putting thousands of scientific experiments on hold for days.
Lab authorities described the monitoring as a precaution, and they, along with outside experts on nuclear engineering, expressed confidence that the blaze would not scatter radioactive material, as some in surrounding communities feared.
"Our facilities, our nuclear materials are all safe, they're accounted for and they're protected," said lab director Charles McMillan.
The twin-engine plane, which can take digital photographs and video as well as thermal and night images, was sent to New York City to take air samples after the Sept. 11 terrorist attacks. It has flown over wildfires and areas damaged by Hurricane Katrina. It monitored the 2002 Winter Olympics in Salt Lake City. It also helped locate debris from the disintegrated space shuttle Columbia shuttle.
"It can look for a wide variety of chemical constituents in a plume and the plumes can originate from fires, from explosions, from a wide variety of sources," said lab spokesman Kevin Roark.
And in a testament to the sophisticated research done at Los Alamos, the plane was developed with technology from the lab, the desert installation that built the atomic bomb during World War II.
The pillars of smoke that can be seen as far as Albuquerque, 60 miles away, have people on edge. The fire has also cast a haze as far away as Kansas. But officials said they analyzed samples taken Tuesday night from some of the lab's monitors and the results showed nothing abnormal in the smoke.
Anti-nuclear groups have sounded the alarm about thousands of 55-gallon drums containing low-grade nuclear waste _ gloves, tools and other contaminated items _ about two miles from the fire. Lab officials said it was highly unlikely the blaze would reach the drums, and that the steel containers can in any case withstand flames and will be sprayed with fire-resistant foam if necessary.
Kevin Smith, site manager for the National Nuclear Security Administration, said the lab's precautions have been scrutinized by dozens of experts.
The lab has been shut down since Monday, when all of the city of Los Alamos and some of its surrounding areas _ 12,000 people in all _ was evacuated. The fire has held up research on such topics as renewable energy, AIDS and particle physics.
"We have 10,000 experiments running at the same time," said Terry Wallace, science chief at the lab. "We'll have to do an analysis to see what's been affected and how it's been affected."
Among the experiments delayed by the fire was computer modeling on the two supercomputers at the lab, the Roadrunner and Cielo. The National Security Administration's three national laboratories _ Los Alamos, Sandia, and Lawrence Livermore _ all share computing time on Cielo, which is among the world's fastest computers. It was unclear which laboratory lost time, but McMillan said teams will examine priorities once the lab reopens.
The plane is just one part of an elaborate air monitoring network surrounding the lab. The lab and the New Mexico Environment Department have dozens of monitors on the ground throughout the region. McMillan said four high-volume air samplers were deployed Tuesday and more were on their way Wednesday.
Some experts familiar with the Los Alamos lab said there is no reason to fear that flames will scatter radiation.
"The nuclear materials are secure," said Penn State University nuclear engineering professor Barry Scheetz, who has served on National Academy of Sciences nuclear review boards and has been to Los Alamos several times. "There's multiple redundancy in the protection of this material. It's not just laying out. It's not there so that a fire is going to disrupt it there and disperse it. The procedures that are in place to protect this material are tremendous."
He added: "The U.S. government, the Department of Energy, has spent literally hundreds of millions of dollars for scenarios that are so unlikely to occur that it is even ridiculous to think about."
The worst-case scenario Energy Department planners could envision for a fire at Los Alamos would release less than 25 rems or radiation _ a dosage that is below short and long-term health concerns, according to a 1998 Environmental Impact Statement for operating the lab written by the department.
The same report said that wildfires are also one of the most likely risks for the lab, along with earthquakes. A bad wildfire is likely to happen at the lab about once a decade, the report said.
The lab was set for idle days again Thursday and Friday.
With no lab employees, residents or shopkeepers around, Los Alamos remained a virtual ghost town.
The economic impact of shutting down the town was already weighing on the minds of city officials and business owners.
"Everybody here is a small business," said Ron Selvage, owner of the Best Western Hilltop House, the only hotel that was open and filled with firefighters, helicopter pilots and journalists. "We'll be all right, but all these other businesses still have the same bills they have to pay and no money coming in."
With the fire continuing to send up columns of smoke on the outskirts of town, fire officials said Wednesday they would not let residents return until it was safe.
The blaze was only 3 percent contained and the weather forecast called for more erratic winds in the coming days.
U.S. Agriculture Secretary Tom Vilsack on Wednesday toured the area from the air and on the ground as part of a swing through portions of New Mexico and Arizona that have been ravaged in recent weeks by wildfire. He said it was clear how fast the Las Conchas fire had expanded.
"At this point in time, we are comforted by the fact that the lab has not been impacted and there haven't been, according to the Department of Energy, any compromises to operations there in terms of waste material and things of that nature," he said. "We're working hard to try to contain that fire as quickly as possible."
Vilsack oversees the U.S. Forest Service, which has nearly 9,000 personnel assigned to more than 130 wildfires across the United States. Most of them are focused on fires burning in the Southwest.
AP Science Writer Seth Borenstein contributed to this report from Washington, D.C. Montoya contributed from Albuquerque.