WASHINGTON (AP) _ The Bush administration took a major step Friday toward building a new generation of nuclear warheads, selecting a design that is being touted as safer, more secure and more easily maintained than today's arsenal.
A team of scientists from Lawrence Livermore National Laboratory will proceed with the weapons design with an anticipation that the first warheads may be ready by 2012 as a replacement for Trident missiles on submarines.
The new weapons program, which has received cautious support from Congress, was immediately criticized by some nuclear nonproliferation groups as a signal that the government wants to expand nuclear weapons production _ not move toward eliminating the stockpile.
Critics also maintain that it sends the wrong signal around the world by pushing a new warhead _ although characterized as a replacement for existing ones_ at a time the United States is trying to curtail nuclear weapons development in North Korea and Iran.
``This is not about starting a new nuclear arms race,'' countered Thomas P. D'Agostino, acting head of the DOE's National Nuclear Security Administration, which oversees the nuclear weapons programs.
Steve Henry, deputy assistant to the secretary of defense for nuclear matters, said the new design is hoped to lead to fewer warheads being needed. He said it has not changed administration determination to reduce the number of deployed warheads to fewer than 2,000 _ the lowest number since the 1950s.
There are believed to be about 6,000 warheads deployed and another 4,000 in reserve.
D'Agostino, briefing reporter on the design decision, said the intent is to develop a safer, more secure warhead to assure increased reliability without the need for underground nuclear tests.
He cautioned that the program remains in the early stages and that in coming months the Livermore team will expand on its design work to give a better estimate on overall costs, the scope of the program and a schedule toward full-scale engineering and production.
The administration is asking for $119 million for the next fiscal year for design work. The officials said they could not say how much the program eventually will cost.
The so-called ``reliable replacement warhead'' has been the focus of a yearlong, intense design competition between Livermore in California and nuclear scientists at the Los Alamos National Laboratory in New Mexico _ the government's two premier nuclear weapons labs.
Both of the labs developed proposals and at one point there was discussion to combine the designs into a single program. But that was rejected and D'Agostino made clear Friday the program would be Livermore's to develop.
The Livermore design was based on an existing warhead that reportedly had been exploded in an underground test in the 1980s, although never actually put into the stockpile. The Los Alamos design was based on a totally fresh approach but without a history of actual testing.
It was this ``very robust test pedigree'' _ as D'Agostino put it _ that gave Livermore the upper hand.
``It ... gave us the confidence ... to certify and go forward without underground testing,'' he said, adding that without that assurance ``we were not going to go forward.''
Congress authorized design work on the new warhead in 2005, but with a stipulation that its primary goal be to assure the reliability of the nuclear arsenal without resumption of bomb testing, and that it will help in the consolidation of the Energy Department's nuclear weapons complex.
Some lawmakers have also questioned whether the new warhead is needed, especially in light of a recent finding that the plutonium in the current warheads will last nearly 100 years, twice as long as previously thought.
Rep. Ellen Tauscher, D-Calif., has planned a hearing on the new warhead later this month, seeking assurance the design will not require further underground tests and will lead to a reduction of warheads and allow a smaller weapons complex.
Some nuclear weapons critics warned the warhead could lead to an increased likelihood of future testing, calling it a ploy to rebuild _ not dismantle _ the nuclear weapons infrastructure.
``This is a first installment on a plan to develop and produce warheads on an ongoing cyclical basis ... similar to what we had during the Cold War,'' said Lisbeth Gronlund, a scientist at the Union of Concerned Scientists, a nuclear nonproliferation advocacy group.
John Isaacs, executive director of the Center for Arms Control and Nonproliferation, said there's no need for a new warhead when ``the U.S. nuclear stockpile, based on 50 years of research and over 1,000 underground nuclear tests, has been confirmed safe and reliable for at least another half-century.''
``The bottom line is we're returning to what we used to do in the Cold War years. That's the message to the world,'' said Hans Kristensen, director of the nuclear information project of the Federation of American Scientists.