Federal officials say the program would produce a total of 330 pounds over 30 years at the Idaho National Laboratory, a sprawling site outside Idaho Falls about 100 miles to the west and upwind of Grand Teton National Park in Wyoming. Officials say the program could cost $1.5 billion and generate more than 50,000 drums of hazardous and radioactive waste.
Project managers say that most if not all of the new plutonium is intended for secret missions and declined to divulge any details. But in the past, it has powered espionage devices.
''The real reason we're starting production is for national security,'' Timothy Frazier, head of radioisotope power systems at the Department of Energy, said in a recent interview.
He vigorously denied that any of the classified missions would involve nuclear arms, satellites or weapons in space.
The laboratory is a source of pride and employment for many residents in the Idaho Falls area. But the secrecy is adding to unease in Wyoming, where environmentalists are scrutinizing the production plan - made public late Friday - and considering whether to fight it.
They say the production effort is a potential threat to nearby ecosystems, including Yellowstone National Park, Grand Teton National Park and the area around Jackson Hole, famous for its billionaires, celebrities and weekend cowboys, including Vice President Dick Cheney.
''It's completely wrapped in the flag,'' said Mary Woollen-Mitchell, executive director of Keep Yellowstone Nuclear Free, a group based in Jackson Hole.
''People are starting to pay attention,'' she said of the production plan. ''On the street, just picking up my kids at school, they're getting keyed up that something is in the works.''
Plutonium 238 has no central role in nuclear arms. Instead, it is valued for its steady heat, which can be turned into electricity.
Federal and private experts unconnected to the project said the new plutonium would probably power devices for conducting espionage on land and under the sea. Even if no formal plans now exist to use the plutonium in space for military purposes, these experts said that the material could be used by the military to power compact spy satellites that would be hard for adversaries to track, evade or destroy.
