U.S. Redesigning Atomic Weapons
By WILLIAM J. BROAD
Published: February 7, 2005
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Worried that the nation's aging nuclear arsenal is increasingly fragile,
American scientists have begun designing a new generation of nuclear arms
meant to be sturdier and more reliable and to have longer lives, federal
officials and private experts say.
The officials say the program could help shrink the arsenal and the high
cost of its maintenance. But critics say it could needlessly resuscitate the
complex of factories and laboratories that make nuclear weapons and could
possibly ignite a new arms race.
So far, the quiet effort involves only $9 million for warhead designers at
the nation's three nuclear weapon laboratories, Los Alamos, Livermore and
Sandia. Federal bomb experts at these heavily guarded facilities are now
scrutinizing secret arms data gathered over a half century for clues about
how to achieve the new reliability goals.
The relatively small initial program, involving fewer than 100 people, is
expected to grow and produce finished designs in the next 5 to 10 years,
culminating, if approval is sought and won, in prototype warheads. Most
important, officials say, the effort marks a fundamental shift in design
For decades, the bomb makers sought to use the latest technologies and most
innovative methods. The resulting warheads were lightweight, very powerful
and in some cases so small that a dozen could fit atop a slender missile.
The American style was distinctive. Most other nuclear powers, years behind
the atomic curve and often lacking top skills and materials, settled for
less. Their nuclear arms tended to be ponderous if dependable, more like
Chevys than racecars.
Now, American designers are studying how to reverse course and make arms
that are more robust, in some ways emulating their rivals in an effort to
avoid the uncertainties and deteriorations of nuclear old age. Federal
experts worry that critical parts of the arsenal, if ever needed, may fail.
Originally, the roughly 10,000 warheads in the American arsenal had an
expected lifetime of about 15 years, officials say. The average age is now
about 20 years, and some are much older. Experts say a costly federal
program to assess and maintain their health cannot ultimately confirm their
reliability because a global test ban forbids underground test detonations.
In late November, Congress approved a small, largely unnoticed budget item
that started the new design effort, known as the Reliable Replacement
Warhead program. Federal officials say the designs could eventually help
recast the nuclear arsenal with warheads that are more rugged and have much
"It's important," said John R. Harvey, director of policy planning at the
National Nuclear Security Administration, which oversees the arsenal. In an
interview, he said the goal of the new program was to create arms that are
not only "inherently reliable" but also easier to make and certify as
"Our labs have been thinking about this problem off and on for 20 years,"
Dr. Harvey said. "The goal is to see if we can make smarter, cheaper and
more easily manufactured designs that we can readily certify as safe and
reliable for the indefinite future - and do so without nuclear testing."
Representative David L. Hobson, an Ohio Republican and chairman of the House
Appropriations Subcommittee on Energy and Water Development, praised the
program in a speech on Thursday and said it could lead to an opportunity for
drastic cuts in the nation's nuclear arsenal.
"A more robust replacement warhead, from a reliability standpoint," Mr.
Hobson said, "will provide a hedge that is currently provided by retaining
thousands of unnecessary warheads."
But arms control advocates said the program was probably unneeded and
dangerous. They said that it could start a new arms race if it revived
underground testing and that its invigoration of the nuclear complex might
aid the design of warheads with new military capabilities, possibly making
them more tempting to use in a war.
"The existing stockpile is safe and reliable by all standards," Daryl G.
Kimball, executive director of the Arms Control Association in Washington,
said in an interview. "So to design a new warhead that is even more robust
is a redundant activity that could be a pretext for designing a weapon that
has a new military mission."
The reliability issue goes back to the earliest days of the nuclear era. At
first, the bombs were huge and trustworthy. The first one, dropped in 1945,
weighed five tons. The first deliverable hydrogen bomb, which made its debut
in 1954, weighed four times as much and had hundreds of times the
destructive power. It measured nearly 25 feet long from nose to tailfins.
Over the decades, American designers worked hard to trim the dimensions.
Small size was prized for many reasons. It meant that warheads could fit
into cramped, narrow missile nose cones, which streaked to earth faster than
blunter shapes and were less buffeted by winds during the fiery plunge,
making them more accurate. It also meant that ships, bombers and submarines
could carry more nuclear arms.
By the 1970's, warheads for missiles weighed a few hundred pounds and packed
the power of dozens of Hiroshima-sized bombs. The arms continued to shrink
and grow more powerful. The last one for the nation's arsenal was built
Designers had few doubts about reliability because they frequently exploded
arms in Nevada at an underground test site. But in 1992, after the cold war,
the United States joined a global moratorium on nuclear tests, ending such
In response, the federal government switched from developing nuclear arms to
maintaining them. It had its designers work on computer simulations and
other advanced techniques to check potency and understand flaws that might
The cost of the nuclear program began at $4 billion a year. It is now more
than $6 billion and includes a growing number of efforts to refurbish and
extend the life of aging warheads.
By the late 1990's, top officials and experts began to openly question
whether such maintenance could continue to stave off deterioration and
ensure the arsenal's reliability. As a solution, some called for a new
generation of sturdier designs.
The new program involves fewer than 100 full- and part-time designers and
other experts and support staff, said Dr. Harvey, of the National Nuclear
"There's not a lot of hardware," he added. "It's mostly concept and
feasibility studies that don't require much fieldwork."
Dr. Harvey emphasized that the effort centered on research and not arms
production. But he said the culminating stages of the program would include
"the full-scale engineering development" of new prototype warheads. Both
Congress and a future administration would have to approve the costly,
advanced work, and an official said no decision had been made to seek such
The current goal of the program, Dr. Harvey said, is to "relax some of the
design constraints imposed on the cold war systems." He added that a
possible area of investigation was using more uranium than plutonium, a
finicky metal that is chemically reactive.
He said the new designs would also stress easier manufacturing techniques
and avoid hazardous and hard-to-find materials.
"Our goal is to carry out this program without the need for nuclear
testing," Dr. Harvey said. "But there's no guarantees in this business, and
I can't prove to you that I can do that right now." Another official,
speaking on the condition of anonymity because the topic is politically
delicate, said that such testing would come only as a last resort and that
the Bush administration's policy was to maintain the moratorium.
The program, Dr. Harvey said, should produce a wide variety of designs. The
Defense Department, which is participating in the effort, will help decide
which weapons will be replaced, he said.
"What we're looking at now is a long-term vision," Dr. Harvey said. "We're
tying to flesh this out and understand the path we need to be on, and to
work with Congress to get a consensus."
Some critics say checking the reliability of the new designs is likely to
require underground testing, violating the ban and inviting other nations to
do the same, thereby endangering American security.
Dr. P. Leonardo Mascheroni, a former Los Alamos scientist who is critical of
the new program, said that it would require not only testing but also
changes in delivery systems costing "trillions of dollars" because of its
large, heavy warheads. Federal officials deny both assertions, saying the
goal is to have new designs fit existing bombers and missiles.
Dr. Mascheroni has proposed that federal designers make lighter, robust
warheads and confirm their reliability with an innovative system of tiny
nuclear blasts. That would still require a revision of the test ban treaty,
he said in an interview, but it would save a great deal of money and avoid
the political firestorm that would probably accompany any effort to resume
Robert S. Norris, a senior nuclear expert at the Natural Resources Defense
Council, a private group in Washington that advocates arms control and
monitors nuclear trends, said too little was known publicly about the
initiative to adequately weigh its risks and benefits, and that for now it
raised more questions than it answered.
"These are big decisions," Mr. Norris said. "They could backfire and come
back to haunt us."