WASHINGTON - The United States is dismantling unneeded nuclear warheads at a faster pace than forecast as it substantially reduces its atomic arsenal under terms of an arms control treaty with Russia, government officials said yesterday.
The Bush administration planned to announce today that it has taken apart three times as many reserve warheads in the just-completed budget year than it had projected and expects the rapid pace of dismantling to continue.
At the same time, a report by an independent science advisory group has concluded that "substantial work remains" before a new generation of warheads will be fit for certification without underground nuclear testing.
The findings are expected to provide congressional opponents of the warhead program with additional reasons to hold back money for the project. The administration views development of the replacement warhead as essential for keeping a secure and more easily maintained nuclear stockpile as warheads age.
The National Nuclear Security Administration, part of the Energy Department, reported a 146 percent increase in dismantled nuclear warheads during the 2007 federal budget year, which ended yesterday. That is triple the agency's original goal.
The agency is believed to be dismantling thousands of warheads, taking out their plutonium, uranium, and nonnuclear high explosive components. The agency did not say how many warheads it had taken apart, nor how many remain to be worked on because the numbers are classified.
The progress "sends a clear message to the world that this administration remains committed to reducing the number of nuclear weapons in the US nuclear stockpile," said Thomas D'Agostino, the agency's administrator.
The government will not provide any numbers on the overall size of the nuclear stockpile, but there are believed to be nearly 6,000 warheads that are deployed or in active reserve.
Under the 2002 treaty with Russia, the United States is committed to reducing the number of deployed warheads to 1,700 to 2,200 by 2012.
Three years ago, President Bush said he wanted the overall stockpile reduced to half of what it was in the 1950s, about one-quarter of its size at the end of the Cold War.
The group of scientists who regularly advise the government on nuclear weapons matters has told Congress that the proposed replacement warhead will require further development and experiments to ensure against possible failure, without underground testing.
Officials at the nuclear agency said they were gratified that the report supported the idea that the replacement warhead can be developed without detonating a device in an underground test.