(LOS ALAMOS, N.M.) -- The wildfire that surrounds the nuclear lab in Los Alamos, New Mexico, has grown to at least 61,000 acres amid mounting concerns about what might be in the smoke from the blaze that's so big it's visible from space.
Such fear has prompted the Environmental Protection Agency to bring in air monitors, along with a special airplane that checks for radiation levels. So far officials have not been able to find anything.
"Our facilities and nuclear material are protected and safe," Laboratory Director Dr. Charles McMillan told ABC News.
The Los Alamos facility -- the birthplace of the atomic bomb -- was shrouded in secrecy long before it was surrounded by smoke after the Las Conchas fire began Sunday.
"It contains approximately 20,000 barrels of nuclear waste," former top security official Glen Walp said. "It's not contained within a concrete, brick and mortar-type building, but rather in a sort of fabric-type building that a fire could easily consume."
"Potential is high for a major calamity if the fire would reach these areas," he added.
Reports have indicated that the flames from the 95-square-mile fire have reached as close as 50 feet from the grounds. With a wildfire this close, lab officials, along with government officials such as New Mexico Gov. Susana Martinez, are trying to reassure the public of the plant's safety.
"I'm confident in saying that they are committed to making it safe," Martinez told ABC News.
After a mass evacuation, the city of Los Alamos remains a ghost town. Most of its 12,000 residents were evacuated Monday, some leaving their sprinklers on to protect their homes.
Still, according to Police Chief Wayne Torpy, about 150 die-hard residents have stayed behind, unfazed by the danger presented by their nuclear neighbor.
Firefighters have made progress in the past few days, and have said that the risk of the flames reaching radioactive material is slim. Still, they caution that winds Wednesday could change, as could their level of confidence.
Copyright 2011 ABC News Radio