WASHINGTON — The Department of Energy announced today that it has selected a design for a new hydrogen bomb to replace a warhead (W76) deployed on submarines. The so-called Reliable Replacement Warhead would be the first in a series of new bomb designs intended to replace all U.S. nuclear warheads over the next two to three decades.

Below is a statement by Dr. Robert Nelson, a physicist and senior scientist with the Union of Concerned Scientists' Global Security Program.

"There is no technical reason to replace existing U.S. nuclear warheads, because they are already highly reliable. According to the Energy Department's own research, the core plutonium components in current weapons will last at least 85 years and possibly much longer. New designs are more likely to introduce new uncertainties.

"It is dangerous that the Energy Department wants to pay for the new warheads by cutting funds for maintaining the existing stockpile, a strategy that will make current weapons less reliable.

"Building these new warheads also will increase pressure to test them. The United States has never deployed a new nuclear warhead without conducting a nuclear explosive test. Since 1992, we've had a moratorium on nuclear testing, but this new weapons program opens the door to new testing.

"Building these new warheads will restart the Cold War cycle of designing and producing new nuclear weapons. Instead, the United States needs a thorough review of its outdated nuclear weapons policy, under which it keeps thousands of warheads on high-alert status. Rather than building new nuclear weapons, the United States should be looking for ways to reduce its reliance on them."