LIVERMORE, Calif.—Federal officials have moved a step closer to doubling the amount of plutonium and increasing weapons work at Lawrence Livermore Lab with the completion of a new environmental plan for the facility.

The plan would allow the amount of plutonium stored at the lab to be increased from 1,540 to 3,000 pounds over the next decade—enough to make hundreds of nuclear weapons.

If the plan is approved, the lab could also double the amount of plutonium that workers in a single room could handle so scientists could do multiple projects simultaneously.

The changes are detailed in an environmental impact statement conducted by the National Nuclear Society Administration to be released Friday.

They’re aimed in part at creating an experimental production line for casting plutonium pits, or nuclear bomb cores.

When these pits—small, hollow shells—are wrapped in explosive and plugged with detonators, they serve as the miniature A-bombs that touch off thermonuclear weapons.

“Where they’ve chosen to work the bugs out of the technology for a bomb factory is a highly populated area riddled with earthquake faults,” complained Marylia Kelley, head of the Livermore-based watchdog group Tri-Valley CAREs. “It’s crazy. If you tried, you could not find a more inappropriate location.”

More than 9,000 people commented on the government’s draft proposals, most of them critical.

“I think the general public understands that the NNSA is looking after homeland security and is improving security not only for them and their families but also the world,” said Tom Grim, who managed the study for the NNSA.