The United States has been quietly researching a new generation of "mini-nukes," low-yield nuclear weapons that can penetrate hardened underground bunkers, officials said Wednesday.
The weapons would have the advantage of great strength but minimal nuclear fallout because of their underground detonation, said the officials.
The research, which is being described as a "conceptual paper study," began about 18 months ago and is being conducted at the Energy Department's three nuclear laboratories at the request of the Air Force, scientists said.
"It's a "what if' project, to see what is possible," said John Immele, associate director for nuclear weapons technology at the Los Alamos National Laboratory in New Mexico.
Immele and other scientists said they doubted the project would progress beyond a paper study, given the current climate of defense cutbacks and reductions of nuclear arsenals.
But William Arkin, director of military research for the Greenpeace environmental movement, said he was worried that military and scientific proponents of mini-nukes would manage to overcome political constraints against the development of new nuclear weapons by convincing policy makers that the weapons were small and containable.
Arkin also rejected the labs' assertions that the research was harmless. Not only does it risk escalating a nuclear arms race with Russia, he said, but it would encourage countries with nuclear ambitions such as Iraq and Iran.