Los Alamos National Laboratory, the U.S. government's largest nuclear research center, plans to cut 5 to 10 percent of its workforce to cope with a $300 million budget cut for the New Mexico lab this year.

The laboratory yesterday asked the National Nuclear Security Administration, a division of the Department of Energy, for permission to eliminate between 400 and 800 positions at the facility, which focuses on nuclear weapons, energy and basic science.

Fewer employees than usual have left Los Alamos within the past three years, likely due to the slow economy. To avoid layoffs, the laboratory will offer packages for some of its 7,585 employees to leave voluntarily, following a similar program in 2008.

"Our current budget and future outlook require significant cost-cutting," Director Charlie McMillan said in a statement. "The plan we're submitting will position the lab to continue executing our missions today and in the future."

National laboratories braced for major cuts to their research programs last year, when House Republicans passed a spending bill that would cut funding for DOE's Office of Science by 18 percent. The final deal for fiscal 2012 cut funding by 0.6 percent from the previous year, leaving it at $4.9 billion, but laboratories took an outsized hit.

They are just now starting to show the effects.

Idaho National Laboratory, which focuses on nuclear reactor research, made a similar announcement earlier this month. The laboratory, which is the second-largest employer in Idaho, announced that it wants to cut as many as 185 of its 8,000 positions to save money after seeing its funding from DOE fall by 9 percent this year, to $1 billion.

Los Alamos is getting $1.95 billion from DOE for fiscal 2012, a 10 percent reduction that led the laboratory to cut its total budget from $2.55 billion to $2.2 billion. President Obama has proposed an additional 3 percent cut in fiscal 2013 for the laboratory, which is run jointly by Bechtel National Inc., the University of California, Babcock & Wilcox Co. and URS Corp.

Most notably, the president's budget blueprint would postpone for at least five years the construction of the Chemistry and Metallurgy Research Replacement Nuclear Facility, or CMRR, a $6 billion plutonium research lab that has become controversial for its cost and the potential to allow for the production of new nuclear weapons.

Senate Energy and Natural Resources Chairman Jeff Bingaman (D-N.M.) and other members of New Mexico's delegation questioned the sudden turnaround on the CMRR. Bingaman also questioned the cut in funding for energy research while nuclear funding remained mostly flat.

"The long-term health of the national laboratories in New Mexico is dependent on maintaining broad-based excellence in energy as well as defense areas," he said upon the release of Obama's budget proposal. "There seems to be a continuing trend by DOE civilian programs to look to other DOE laboratories as they increase their programs."