Global Security Newswire
Daily News on Nuclear, Biological & Chemical Weapons, Terrorism and Related Issues
NNSA Chief Sees Opportunity, Challenge in Merging Two Warhead Updates
WASHINGTON -- The head of U.S. nuclear security said he sees both benefits and hurdles in a possible effort to overhaul two different nuclear warhead designs using a single update package (see GSN, Dec. 24, 2009).
The Obama administration has requested that Congress appropriate $26 million in fiscal 2011 to study what it would take to initiate a joint program to refurbish the W-78 warhead, used on Air Force Minuteman 3 ICBMs, and the W-88 warhead, which sits atop Navy Trident D-5 submarine-launched ballistic missiles.
"There are opportunities to potentially have fewer life extensions" by combining efforts that typically cost billions of dollars for each warhead design, Thomas D'Agostino, who leads the National Nuclear Security Administration, told reporters last week.
Most of the nation's roughly 2,200 deployed warheads are several decades old and require periodic maintenance and updates to remain viable.
The New START agreement, signed by U.S. President Barack Obama and Russian President Dmitry Medvedev last spring, would reduce the size of the stockpile to 1,550 warheads in the coming years (see related GSN story, today). As it stands, the Air Force fields 250 W-78 warheads and the Navy deploys 384 W-88 warheads, according to nuclear weapons analysts Robert Norris and Hans Kristensen.
To save money, some experts have called for reducing diversity in warhead types that must be maintained into the future. There are currently a dozen or so warhead designs in the U.S. stockpile, but those might be winnowed down to about half that number over the next few decades, one Air Force official told Global Security Newswire last December.
Under the approach to be studied by NNSA officials, D'Agostino's agency would collaborate with the Navy and Air Force to swap out aging components in the explosive portion of the two distinct warheads for a standardized set of more modern replacement parts.
It might even involve mixing and matching primaries and secondaries -- the two explosive stages of thermonuclear weapons -- in the weapons to be overhauled, the official said late last year.
Using such a combined effort on the W-78 and W-88, the nuclear agency could "drive some efficiencies [and] make sure that the system that is put together can satisfy both the Navy and the Air Force needs," the NNSA administrator said at a Friday lunch session.
However, fitting two divergent warhead designs with a single update package would entail some costs of its own. Although the W-78 and W-88 warheads were both designed for use on ballistic missiles, they were meant to fly on different delivery vehicles and do not share a common command and control system.
With funding in the budget year that begins Oct. 1, physicists and engineers at the nation's nuclear laboratories would study what it would take to bridge these differences in a shared life-extension effort.
"These devices have to fit in the different ... re-entry vehicles," D'Agostino said. "The interface and connections are different" between the warhead and the hardware on which it rides, he said. So, too, are the centers of mass different between the two systems, which could affect ballistic flight.
"Those are tough engineering problems. They're not insurmountable at all. They just require a bit of work. We clearly have the capability to do it," said the NNSA chief. "And that's why we want to do the study. It doesn't mean we're going to end up that way. But we think there's some benefit."
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