Now, officials believe the bad guys know the secret too.
Classified nuclear threat reports warn that rogue countries and
terrorists have learned it is possible to make atomic bombs using
low-enriched uranium, a common fuel for nuclear reactors used to
conduct research and generate power. The reports, described to USA
TODAY by top federal officials, also conclude that it would be
easier than previously believed for enemies of the United States to
make such weapons using spent nuclear fuel, the waste generated by
Neither of those substances is listed as ''weapons usable'' under
U.S. or international security protocols. As a result, they get
little protection from theft at civilian nuclear reactors worldwide.
That includes reactors in former Soviet states and nations such as
Indonesia, where public sympathy runs high for Iraq and
And the threats are real.
Five years ago, U.S. scientists at Los Alamos National Laboratory
secretly designed an atomic bomb with low-enriched uranium, USA
TODAY has learned. The bomb, which could have fit easily in a small
pickup, was weak in nuclear terms but strong enough to destroy a
square mile of a city.
U.S. scientists also have proved in experiments that it is
possible to create nuclear weapons using several elements that could
be extracted from spent fuel by a rogue state or perhaps even a
well-organized terrorist organization.
Officials stress that there is no evidence that al-Qaeda or any
other terror group has the skills or tools to build an atomic bomb
using low-enriched uranium or spent fuel. There's a big gap, they
say, between knowing such things are possible and being able to do
them. Rogue states are a bigger concern: U.S. officials believe that
Iran and North Korea (news
sites) are trying to develop the capability to make nuclear
weapons using spent fuel.
Yet U.S. efforts to stop the spread of nuclear weapons still
focus almost exclusively on protecting plutonium and highly enriched
uranium, the traditional ''weapons usable'' nuclear materials. That
atomic bombs can be made with little or none of those substances
reveals significant gaps in current programs to keep rogue states
and terrorists from developing a nuclear capability.
Under U.S. and international protocols for protecting nuclear
materials, facilities handling low-enriched uranium or spent fuel
are not obliged to have armed guards or security systems to stop
break-ins or insider thefts. Such measures are expected of nuclear
installations holding plutonium or highly enriched uranium.
Accounting and inventory rules also are far less stringent for
material not deemed ''weapons usable.''
Officials at the International Atomic Energy Agency, the arm of
the United Nations (news
sites) that monitors nuclear stocks worldwide, say such
distinctions are appropriate because plutonium and highly enriched
uranium remain the most effective and easy-to-use materials for
making nuclear weapons.
''We work on the assumption that rogue states, or terrorists for
that matter, know how to make (nuclear) weapons with small amounts
of material and different types and combinations of material. But
we've been advised by experts with the nuclear weapons states that
it would be very difficult,'' says Davis Hurt, a senior safeguards
expert at the agency.
The agency, based in Vienna, has to focus its oversight on the
biggest threats, Hurt says. Expanded monitoring of other materials,
such as low-enriched uranium, wouldn't be possible unless the
agency's member states provided money to boost its budget, he
Cracking nuclear myths
From the dawn of the atomic age, nuclear weapons have relied on
plutonium or highly enriched uranium for their explosive punch.
Highly enriched uranium is easier to make and to use. It is
created by processing natural uranium to boost its concentration of
uranium-235, the element's most fissionable isotope. Once that
concentration is sufficient, it's relatively easy to make a
''gun-type'' atomic bomb, which slams masses of enriched uranium
together in a gun barrel-like tube. That was the type of bomb the
U.S. dropped on Hiroshima in 1945.
Plutonium is more of a challenge to make because it requires
running uranium through a nuclear reactor. It's also harder to
fashion into a bomb: a plutonium ''pit'' has to be surrounded with
conventional explosives that are precisely detonated to compress the
material and create a critical reaction. But plutonium weapons yield
much bigger blasts with far less material.
In the 1960s, as nuclear power went global, U.S. officials
successfully pushed for international standards to keep plutonium
and enriched-uranium stockpiles secure. The International Atomic
Energy Agency monitors compliance with voluntary measures through
inspections and inventory checks. Physical protections -- guards,
gates and guns -- are the responsibility of each nation, and the
agency cannot mandate such measures.
The agency's protocols and inspection programs fail in several
ways to account for types and amounts of materials that can serve as
fuels for a nuclear device:
* Low-enriched uranium, or uranium containing less than 20% of
the U-235 isotope, is not labeled ''weapons usable'' under either
U.S. or international standards. Reactors using the fuel are
inspected once a year versus once a month for those using plutonium
or highly enriched uranium. They also have more leeway in accounting
for material that goes missing.
Many of the world's research reactors use low-enriched uranium
with U-235 concentrations just below 20%. That material can, as Los
Alamos proved, create a nuclear blast, though making a bomb with it
requires substantial skill and a relatively large amount of
material. The United States helped convert many of those reactors
from highly enriched uranium.
Some reactors run on uranium enriched to less than 5%, which
cannot sustain the critical reaction for nuclear weapons. But even
that material would carry risks in the hands of a rogue state
because it is relatively easy to boost its enrichment enough for
''If you got a stack of uranium enriched to 4-5%, which as a rule
is not seriously protected, the plant needed to convert it to 90%
enrichment is potentially small and easy to hide,'' Harvard
University physicist Matthew Bunn says.
* Spent reactor fuel, which cannot be used directly to make an
atomic bomb, is a growing concern among authorities because it can
be processed to extract materials that can be used for nuclear
weapons. The work demands sophisticated skills and equipment, but
it's not the challenge it once was.
The United States ''reprocessed'' spent fuel from nuclear
reactors for decades to recover plutonium for weapons. And U.S.
scientists have proved recently that other, less-recognized elements
in spent fuel, such as neptunium and americium, also can sustain the
chain reaction needed for nuclear blasts.
Security for spent fuel often is a low priority because it is
seen as too radioactive to handle. But U.S. scientists have warned
for years that poorly guarded spent fuel caches in some countries
have sat for so long that radioactivity has dissipated and poses
less of a risk.
A recently declassified study by Lawrence Livermore National
Laboratory in 1995 found that rogue states or terrorists would need
only ''modest facilities and equipment'' to extract weapons-ready
nuclear material from spent fuel.
* The amount of nuclear fuel needed to build a bomb is far less
than what is officially stated.
The International Atomic Energy Agency says it takes 17.6 pounds
of plutonium or 55.1 pounds of highly enriched uranium -- amounts
that could fit in a suitcase -- to build a nuclear weapon. Reactors
holding those amounts or more are inspected with greater
Yet U.S. officials acknowledge that nuclear weapons can be built
using far smaller quantities of those materials.
A 1995 study by the Natural Resources Defense Council found that
terrorists with ''low'' technical ability could build a small
nuclear weapon with about nine pounds of plutonium or 20 pounds of
highly enriched uranium. A more expert program, such as those run by
Iraq, Iran or North Korea, would need about half those amounts, the
study said. Such a bomb would have about a quarter the power of the
one that destroyed Hiroshima.
''It's a lot easier to make a nuclear explosive device -- and
some simple designs require a lot less fissile material -- than the
public has been led to believe,'' says Thomas Cochran, a physicist
who co-authored the study.
New threats perceived
There's debate among U.S. officials over the gravity of the
nuclear threat terrorists or rogue states could pose without
significant amounts of plutonium or highly enriched uranium. In
August, the debate clouded a much-touted mission by U.S., Russian
and international officials to remove more than 100 pounds of highly
enriched uranium from a closed and poorly secured Serbian research
reactor. With Serbia's blessing, the material was taken under heavy
guard to a Russian site where security had been improved with U.S.
Officials never revealed in news briefings that they left behind
a cache of spent fuel laced with at least 10 pounds of plutonium
that could be extracted for weapons. The material remains at the
''Some people wanted to take it -- there was a lot of debate,''
says a U.S. official involved in the mission. ''It would have been a
lot of work -- more than two tons of additional material in a lot of
containers. But our understanding is that the plutonium may be
concentrated in certain containers, so if a bad guy got the right
ones, he could get some good stuff.''
Assessing the risk is tough because officials don't know what
rogue states and terrorists are capable of doing with different
types of nuclear material. U.S. officials worry, for example, that
al-Qaeda picked up nuclear secrets from sympathetic Pakistani
The other problem is that no one knows how much nuclear material
may be missing around the world. Many research and power reactors
keep shoddy fuel inventories, particularly in former Soviet states
and developing nations. And reports of thefts or losses tallied by
the International Atomic Energy Agency are notoriously spotty.
''No one doubts that there are a number, if not many, instances
of diversion or theft of nuclear material that we're not aware of,''
says William Potter, a non-proliferation expert at the Monterey
Institute of International Studies. Many countries don't disclose
losses, he adds, and intelligence sharing is limited.
Data gathered by the International Atomic Energy Agency and the
Monterey Institute reveal several thefts or losses over the past few
years involving low-enriched uranium and small amounts of
traditional weapons fuel.
A daunting set of solutions
Many officials fear they will undermine the critical mission of
securing big stockpiles of plutonium and highly enriched uranium if
they draw attention to the risk posed by lesser grades or amounts of
Economic woes in the former Soviet states, especially Russia,
have left little money for securing numerous sites storing
weapons-ready nuclear fuel left from the Cold War. U.S. assistance
programs to help consolidate and protect that material have reached
fewer than half the sites of concern.
''We need to have more countries throwing money into the pot,''
says Rose Gottemoeller, a former assistant secretary of Energy now
at the Carnegie Endowment for International Peace.
U.S. officials recently won agreement from the seven other top
economic powers to collectively match a U.S. pledge of $10 billion
over 10 years for non-proliferation efforts. Meanwhile, many experts
say, safeguards must be tightened.
The rules should reflect that information on making bombs with
low-grade nuclear fuel or small amounts of traditional material
''has leaked out more in recent years,'' says Laura Holgate of the
Nuclear Threat Initiative, a non-profit group working to curb the
spread of nuclear arms.
Some critics say they expect no action because the International
Atomic Energy Agency's member states fear that their nuclear
industries would be hurt by the costly measures needed to secure all
the types and quantities of nuclear materials that might be useful
to rogue states or terrorists.
Those nations are ignoring the growing capabilities of those who
would steal material for nuclear weapons, says Cochran of the
Natural Resources Defense Council. ''They're living in 1945,'' he