Kevin Roark, a lab spokesman, said the blaze, known as the Las Conchas fire, has burned one acre in a portion of the lab known as Technical Area 49-- a site used in 1960 and 1961 to test high explosives and radioactive materials, leaving residues of uranium and plutonium in holes drilled 120-feet deep, according to a 2005 lab report.
Roark said the lab will remain closed Tuesday.
Los Alamos County officials ordered the mandatory evacuation of the city of Los Alamos, which has 12,000 residents, because of reports the fire now threatens the town. The county said residents should wait for the automated Reverse 911 phone call. Once called, they should proceed in an orderly fashion to police control points and follow additional instructions.
National Guard and State Police will be assisting with the evacuation, county officials said.
Lawrence Lujan, a spokesman for the Santa Fe National Forest, said a sevenfold increase in the size of the Las Conchas fire in less than 24 hours is due "extreme fire behavior" associated with prolonged drought, hot temperatures, low humidity and high wind, as well as better mapping of the fire by the Forest Service infrared imagery flights over the fire at 3 a.m.(MDT) Monday. The fire had grown to nearly 44,000 acres by Monday afternoon from 6,000 acres on Sunday.
Los Alamos County fire chief Doug Tucker told a press conference that the he does not expect the fire, 40 miles due west of Santa Fe, to dissipate anytime soon, adding, "it has the potential to double or triple in size" before it is contained.
Tucker said that at the moment fire managers had "no idea" which direction the fierce blaze, fanned by winds up to 60 miles an hour, will go. Lujan said wild land fire managers initially had planned to use 12 air tankers and eight helicopters to "bomb" the fire with retardant. But Tucker said high winds have grounded the aircraft.
Other assets battling the fire include seven fire engines and seven highly experienced "hot shot crews," with 20 members each, and 12 initial fire attack crews, also with 20 members, with both types of crews battling fire the hard way -- with shovels.
The fire started on private land at 1 p.m. Sunday, 12 miles southwest of Los Alamos. Hot temperatures, low humidity and high winds "contributed to the intense fire behavior and fire growth," said the multiagency Incident Information System website (InciWeb).
The lab uses plutonium to craft atomic bomb cores. InciWeb reported that "all radioactive material is appropriately accounted for and protected."
According to InciWeb, the fire also has knocked down power and phones lines in the area.
The lab, operated by Los Alamos National Security LLC, a consortium consisting of the University of California, Bechtel, Babcock and Wilcox Technical Services, and URS Energy and Construction, said in a statement on its website that it would be closed Monday "for all activities and nonessential employees are directed to remain off-site. Employees are considered nonessential and should not report to work unless specifically directed by their line managers."
Los Alamos National Security employs about 9,000 workers at the lab, backed up by about 650 contractors and 120 Energy Department employees.
Wild land fire managers have assigned responsibility for battling the Las Conchas fire to a Type 1 Incident Management Team, assigned to handle the most complex fires that can threaten critical infrastructures such as the lab, which besides its classified nuclear weapons work is one of the pre-eminent research labs in the country.
The incident management team is operating from an emergency operations center at the lab, said spokeswoman Lisa Rosenfeld, adding Gov. Martinez visited the center shortly before midnight Sunday.
In May 2000, a controlled burn at nearby Bandelier National Monument grew into a uncontrolled monster fire that raged across 48,000 acres, including 7,500 acres at the lab -- about one-quarter of its area.
That fire, known as the Cerro Grande Fire, spread due to the same dry and windy conditions fueling the Las Conchas fire.
The Cerro Grande fire, according to March 2001 lab report, resulted in the evacuation down a narrow mountain road of lab workers and all 12,000 residents of the City of Los Alamos.
The fire destroyed 239 residential structures, leaving 429 families homeless, and 112 lab structures. "All the buildings that burned were minor, such as trailer offices used by graduate students or storage sheds. No buildings containing nuclear materials or high explosives were burned, although in some cases the fire came very close," the report said.
Roark said the lab learned its lessons from the Cerro Grande fire and has conducted an "aggressive" program to thin the fuels -- vegetation and live and downed timber -- during the past 11 years. The lab, Roark said, is in a much better position to deal with a forest fire than in 2000.
Clarification: The lead was edited to clarify that the fire grew 38,000 acres in 24 hours. More precise size figures were added to the 6th paragraph. These details were mistakenly edited out of the original version of the story.