|PRC Theft of U.S. Nuclear Warhead Design
Information Summary The
People's Republic of China (PRC) has stolen classified information on all of the United
States' most advanced thermonuclear warheads, and several of the associated reentry
vehicles. These thefts are the result of an intelligence collection program spanning two
decades, and continuing to the present. The PRC intelligence collection program included
espionage, review of unclassified publications, and extensive interactions with scientists
from the Department of Energy's national weapons laboratories.
The stolen U.S.
secrets have helped the PRC fabricate and successfully test modern strategic thermonuclear
weapons. The stolen information includes classified information on seven U.S.
thermonuclear warheads, including every currently deployed thermonuclear warhead in the
U.S. intercontinental ballistic missile arsenal. Together, these include the W-88 Trident
D-5 thermonuclear warhead, and the W-56 Minuteman II, the W-62 Minuteman III, the W-70
Lance, the W-76 Trident C-4, the W-78 Minuteman III Mark 12A, and the W-87 Peacekeeper
thermonuclear warheads. The stolen information also includes classified design information
for an enhanced radiation weapon (commonly known as the "neutron bomb"), which
neither the United States, nor any other nation, has ever deployed.
In addition, in the mid-1990s the PRC stole from a U.S. national weapons laboratory
classified U.S. thermonuclear weapons information that cannot be identified in this
unclassified Report. Because this recent espionage case is currently under investigation
and involves sensitive intelligence sources and methods, the Clinton administration has
determined that further information cannot be made public.
The W-88 is a miniaturized, tapered thermonuclear warhead. It is the United States'
most sophisticated strategic thermonuclear weapon. In the U.S. arsenal, the W-88 warhead
is mated to the D-5 submarine-launched ballistic missile carried aboard the Trident
nuclear submarine. The United States learned about the theft of the W-88 Trident D-5
warhead information, as well as about the theft of information regarding several other
thermonuclear weapons, in 1995.
On two occasions, the PRC has stolen classified U.S. information about neutron warheads
from a U.S. national weapons laboratory. The United States learned of these thefts of
classified information on the neutron bomb in 1996 and in the late 1970s, when the first
theft -- including design information on the W-70 warhead -- occurred. The W-70 warhead
contains elements that may be used either as a strategic thermonuclear weapon, or as an
enhanced radiation weapon ("neutron bomb"). The PRC subsequently tested the
neutron bomb. The U.S. has never deployed a neutron weapon.
In addition, the Select Committee is aware of other PRC thefts of U.S. thermonuclear
weapons-related secrets. The Clinton administration has determined that further
information about these thefts cannot be publicly disclosed.
The Select Committee judges that the PRC will exploit elements of the stolen U.S.
design information for the development of the PRC's new generation strategic thermonuclear
warheads. Current PRC silo-based missiles were designed for large, multi-megaton
thermonuclear warheads roughly equivalent to U.S. warheads of the late 1950s. The PRC
plans to supplement these silo-based missiles with smaller, modern mobile missiles that
require smaller warheads. The PRC has three mobile ICBM programs currently underway Đ two
road-mobile and one submarine launched program Đ all of which will be able to strike the
The first of these new People's Liberation Army (PLA) mobile ICBMs, the DF-31, may be
tested in 1999 and could be deployed as soon as 2002. The DF-31 ICBM and the PRC's other
new generation mobile ICBMs will require smaller, more compact warheads. The stolen U.S.
information on the W-70 or W-88 Trident D-5 will be useful for this purpose.
The PRC has the infrastructure and technical ability to use elements of the stolen U.S.
warhead design information in the PLA's next generation of thermonuclear weapons. If the
PRC attempted to deploy an exact replica of the U.S. W-88 Trident D-5 warhead, it would
face considerable technical challenges. However, the PRC could build modern thermonuclear
warheads based on stolen U.S. design information, including the stolen W-88 design
information, using processes similar to those developed or available in a modern aerospace
or precision guided munitions industry. The Select Committee judges that the PRC has such
infrastructure and is capable of producing small thermonuclear warheads based on the
stolen U.S. design information, including the stolen W-88 information.
The Select Committee judges that the PRC is likely to continue its work on advanced
thermonuclear weapons based on the stolen U.S. design information. The PRC could begin
serial production of advanced thermonuclear weapons based on stolen U.S. design
information during the next decade in connection with the development of its new
generation of intercontinental ballistic missiles.
The Select Committee judges that the PRC's acquisition of U.S. classified information
regarding thermonuclear warhead designs from the Department of Energy's national weapons
laboratories saved the PRC years of effort and resources, and helped the PRC in its
efforts to fabricate and successfully test a new generation of thermonuclear warheads. The
PRC's access to, and use of, classified U.S. information does not immediately alter the
strategic balance between the U.S. and PRC. Once the PRC's small, mobile strategic
ballistic missiles are deployed, however, they will be far more difficult to locate than
the PRC's current silo-based missiles. This will make the PRC's strategic nuclear force
more survivable. Small, modern nuclear warheads also enable the PRC to deploy multiple
reentry vehicles (MRVs or MIRVs, multiple independently-targetable reentry vehicles) on
its ICBMs should it choose to do so.
The PRC's collection of intelligence on smaller U.S. thermonuclear warheads began in
the 1970s, when the PRC recognized its weaknesses in physics and the deteriorating status
of its nuclear weapons programs. The Select Committee judges that the PRC's intelligence
collection efforts to develop modern thermonuclear warheads are focused primarily on the
U.S. Department of Energy's National Laboratories at:
- Los Alamos
- Lawrence Livermore
- Oak Ridge
The FBI has investigated a number of U.S. National Laboratory employees in connection
with suspected espionage.
The Select Committee judges that the U.S. national weapons laboratories have been and
are targeted by PRC espionage, and almost certainly remain penetrated by the PRC today.
The United States did not become fully aware of the magnitude of the
counterintelligence problem at Department of Energy national weapons laboratories until
1995. A series of PRC nuclear weapons test explosions from 1992 to 1996 began a debate in
the U.S. Government about whether the PRC's designs for its new generation of nuclear
warheads were in fact based on stolen U.S. classified information. The apparent purpose of
these PRC tests was to develop smaller, lighter thermonuclear warheads, with an increased
yield-to-weight ratio. In 1995, a "walk-in" approached the Central Intelligence
Agency outside the PRC and provided an official PRC document classified "Secret"
that contained specific design information on the W-88 Trident D-5, and technical
information on other thermonuclear warheads. The CIA later determined that the
"walk-in" was directed by the PRC intelligence services. Nonetheless, CIA and
other Intelligence Community analysts that reviewed the document concluded that it
contained U.S. warhead design information.
The National Security Advisor was briefed on PRC thefts of classified U.S.
thermonuclear warhead design information in April 1996 (when he was the Deputy National
Security Advisor), and again in August 1997. In response to specific interrogatories from
the Select Committee, the National Security Advisor informed the Select Committee that the
President was not briefed about the issue and the long-term counterintelligence problems
at the Department of Energy until early 1998. The Secretary of Energy was briefed about
the matter in late 1995 and early 1996. At the writing of this report, the Secretary of
Defense has been briefed, but not the Secretaries of State and Commerce.
Congress was not provided adequate briefings on the extent of the PRC's espionage
Under Presidential Decision Directive 61 issued in February 1998, the Department of
Energy was required to implement improved counterintelligence measures. In December 1998,
the Department of Energy began to implement a series of recommended improvements to its
counterintelligence program approved by Secretary Richardson in November 1998. Based on
testimony by the new head of the Department of Energy's counterintelligence program, the
unsuccessful history of previous counterintelligence programs at the Department of Energy,
and other information that is not publicly available, the Select Committee judges that the
new counterintelligence program at the Department of Energy will not be even minimally
effective until at least the year 2000.
Since the collapse of the Soviet Union, and continuing today, Russia is cooperating
with the PRC in numerous military and civilian programs, including the PRC's civilian
nuclear program. The Select Committee is concerned about the possibility of cooperation
between Russia and the PRC on nuclear weapons. The Select Committee judges that Russian
nuclear weapons testing technology and experience could significantly assist the PRC's
nuclear weapons program, including the PRC's exploitation of stolen U.S. thermonuclear
warhead design information. This is especially true if the PRC complies with the
Comprehensive Test Ban Treaty, which does not permit the physical testing of nuclear
PRC Theft of U.S. Nuclear Warhead Design Information
The People's Republic of China's penetration of our national weapons laboratories spans
at least the past several decades, and almost certainly continues today.
The PRC's nuclear weapons intelligence collection efforts began after the end of the
Cultural Revolution in 1976, when the PRC assessed its weaknesses in physics and the
deteriorating status of its nuclear weapons programs.
The PRC's warhead designs of the late 1970s were large, multi-megaton thermonuclear
weapons that could only be carried on large ballistic missiles and aircraft. The PRC's
warheads were roughly equivalent to U.S. warheads designed in the 1950s. The PRC may have
decided as early as that time to pursue more advanced thermonuclear warheads for its new
generation of ballistic missiles.
The PRC's twenty-year intelligence collection effort against the U.S. has been aimed at
this goal. The PRC employs a "mosaic" approach that capitalizes on the
collection of small bits of information by a large number of individuals, which is then
pieced together in the PRC. This information is obtained through espionage, rigorous
review of U.S. unclassified technical and academic publications, and extensive interaction
with U.S. scientists and Department of Energy laboratories.
The Select Committee judges that the PRC's intelligence collection efforts to develop
modern thermonuclear warheads are focused primarily on the Los Alamos, Lawrence Livermore,
Sandia, and Oak Ridge National Laboratories.
As a result of these efforts, the PRC has stolen classified U.S. thermonuclear design
information that helped it fabricate and successfully test a new generation of strategic
The PRC stole classified information on every currently deployed U.S. intercontinental
ballistic missile (ICBM) and submarine-launched ballistic missile (SLBM). The warheads for
which the PRC stole classified information include: the W-56 Minuteman II ICBM; the W-62
Minuteman III ICBM; the W-70 Lance short-range ballistic missile (SRBM); the W-76 Trident
C-4 SLBM; the W-78 Minuteman III Mark 12A ICBM; the W-87 Peacekeeper ICBM; and the W-88
Trident D-5 SLBM. The W-88 warhead is the most sophisticated strategic nuclear warhead in
the U.S. arsenal. It is deployed on the Trident D-5 submarine-launched missile.
In addition, in the mid-1990s the PRC stole from a U.S. national weapons laboratory
classified U.S. thermonuclear weapons information that cannot be identified in this
unclassified Report. Because this recent espionage case is currently under investigation
and involves sensitive intelligence sources and methods, the Clinton administration has
determined that further information may not be made public.
The PRC also stole classified information on U.S. weapons design concepts, on
weaponization features, and on warhead reentry vehicles (the hardened shell that protects
a warhead during reentry).
The PRC may have acquired detailed documents and blueprints from the U.S. national
The U.S. Intelligence Community reported in 1996 that the PRC stole neutron bomb
technology from a U.S. national weapons laboratory. The PRC had previously stolen design
information on the U.S. W-70 warhead in the late 1970s; that earlier theft, which included
design information, was discovered several months after it took place. The W-70 has
elements that can be used as a strategic thermonuclear warhead or an enhanced radiation
("neutron bomb") warhead. Following the initial theft of W-70 design
information, the PRC tested a neutron bomb in 1988.
Classified U.S. Nuclear Weapons Information Acquired by the PRC
Designation Design Laboratory Weapon Platform
W-88 Los Alamos Trident D-5 SLBM
W-87 Lawrence Livermore Peacekeeper/M-X ICBM
W-78 Los Alamos Minuteman III Mark 12A ICBM
W-76 Los Alamos Trident C-4 SLBM
W-70 Lawrence Livermore Lance SRBM
W-62 Lawrence Livermore Minuteman III ICBM
W-56 Lawrence Livermore Minuteman II ICBM
The PRC may have also acquired classified U.S. nuclear weapons computer codes from U.S.
national weapons laboratories. The Select Committee believes that nuclear weapons computer
codes remain a key target for PRC espionage. Nuclear weapons codes are important for
understanding the workings of nuclear weapons and can assist in weapon design,
maintenance, and adaptation. The PRC could make use of this information, for example, to
adapt stolen U.S. thermonuclear design information to meet the PRC's particular needs and
During the mid-1990s, it was learned that the PRC had acquired U.S. technical
information about insensitive high explosives. Insensitive high explosives are a component
of certain thermonuclear weapons. Insensitive high explosives are less energetic than high
explosives used in some other thermonuclear warheads, but have advantages for other
purposes, such as thermonuclear warheads used on mobile missiles.
The PRC thefts from our national weapons laboratories began at least as early as the
late 1970s, and significant secrets are known to have been stolen as recently as the
mid-1990s. Such thefts almost certainly continue to the present.
The Clinton administration has determined that additional information about PRC thefts
included in this section of the Select Committee's Report cannot be publicly disclosed.
The PRC's Next Generation Nuclear Warheads
The PRC has acquired U.S. nuclear weapons design information that could be utilized in
developing the PRC's next generation of modern thermonuclear warheads.
The Department of Energy identifies two general design paths to the development of
modern thermonuclear warheads:
- The first path, which apparently has been followed by the Russians, emphasizes
simplicity and reliability in design
- The second path, which the U.S. has taken, utilizes innovative designs and
The Select Committee judges that the combination of the PRC's preference for U.S.
designs, the PRC's theft of design information on our most advanced thermonuclear
warheads, and the PRC's demand for small, modern warheads for its new generation of mobile
intercontinental ballistic missiles will result in the PRC emulating the U.S. design path
to develop its next generation of thermonuclear warheads.
The PRC has already begun working on smaller thermonuclear warheads. During the l990s,
the PRC was working to complete testing of its modern thermonuclear weapons before it
signed the Comprehensive Test Ban Treaty in 1996.1 The PRC conducted a series of nuclear
tests from 1992 to 1996. Based on what is known about PRC nuclear testing practices,
combined with data on PRC warhead yield and on PRC missile development, it is clear that
the purpose of the 1992 to 1996 test series was to develop small, light warheads for the
PRC's new nuclear forces.2
These tests led to suspicions in the U.S. Intelligence Community that the PRC had
stolen advanced U.S. thermonuclear warhead design information. These suspicions were
definitely confirmed by the "walk-in" information received in 1995.
The Select Committee judges that the PRC is developing for its next generation of
road-mobile intercontinental ballistic missiles smaller, more compact thermonuclear
warheads that exploit elements of stolen U.S. design information, including the stolen
design information from the U.S. W-70 Lance warhead or the W-88 Trident D-5 warhead.
The following graph shows an unclassified history of the PRC's thermonuclear weapons
development and its acquisition of classified information from the United States.
Completing the development of its next-generation warhead poses challenges for the PRC.
The PRC may not currently be able to match precisely the exact explosive power and other
features of U.S. weapons. Nonetheless, the PRC may be working toward this goal, and the
difficulties it faces are surmountable. Work-arounds exist, using processes similar to
those developed or available in a modern aerospace or precision-guided munitions industry.
The PRC possesses these capabilities already.
The Impact of the PRC's Theft of U.S. Thermonuclear Warhead Design Information
Mobile and Submarine-Launched Missiles
The main application of the stolen U.S. thermonuclear warhead information will likely
be to the PRC's next-generation intercontinental ballistic missiles.
The PRC is developing several new, solid-propellant, mobile intercontinental ballistic
missiles. These include both road-mobile and submarine-launched intercontinental ballistic
Road-mobile ballistic missiles and submarine-launched ballistic missiles require
smaller, more advanced thermonuclear warheads. The Select Committee judges it is likely
that the PRC will use a new, smaller thermonuclear warhead on its next generation
road-mobile, solid-propellant ICBM, the DF-31.
The DF-31 is likely to undergo its first test flight in 1999, and could be deployed as
early as 2002. Introduction of the PRC's new, smaller thermonuclear warhead into PLA
service could coincide with the initial operational capability of the new road-mobile
DF-31 ballistic missile system.
The Select Committee judges that the PRC's thermonuclear warheads will exploit elements
of the U.S. W-70 Lance or W-88 Trident D-5 warheads. While the PRC might not reproduce
exact replicas of these U.S. thermonuclear warheads, elements of the PRC's devices could
Acceleration of PRC Weapons Development
The PRC's theft of classified U.S. weapons design information saved the PRC years of
effort and resources in developing its new generation of modern thermonuclear warheads. It
provided the PRC with access to design information that worked and was within the PRC's
ability to both develop and test. And it saved the PRC from making mistakes or from
pursuing blind alleys.
The loss of design information from the Department of Energy's national weapons
laboratories helped the PRC in its efforts to fabricate and successfully test its next
generation of nuclear weapons designs. These warheads give the PRC small, modern
thermonuclear warheads roughly equivalent to current U.S. warhead yields.
Assessing the extent to which design information losses accelerated the PRC's nuclear
weapons development is complicated because so much is unknown. The full extent of U.S.
information that the PRC acquired and the sophistication of the PRC's indigenous design
capabilities are unclear. Moreover, there is the possibility of third country assistance
to the PRC's nuclear weapons program, which could also assist the PRC's exploitation of
the stolen U.S. nuclear weapons information. Nonetheless, it is patent that the PRC has
stolen significant classified U.S. design information on our most modern thermonuclear
While it is sometimes argued that eventually the PRC might have been able to produce
and test an advanced and modern thermonuclear weapon on its own, the PRC had conducted
only 45 nuclear tests in the more than 30 years from 1964 to 1996 (when the PRC signed the
Comprehensive Test Ban Treaty), which would have been insufficient for the PRC to have
developed advanced thermonuclear warheads on its own. This compares to the approximately
1,030 tests by the United States, 715 tests by the Soviet Union, and 210 by France.3
The following illustrates the evolution of smaller U.S. warheads.4
Effect on PRC Nuclear Doctrine
Deploying new thermonuclear weapons provides the PRC with additional doctrinal and
operational options for its strategic forces that, if exercised, would be troublesome for
the United States.
Smaller, more efficient thermonuclear warheads would provide the PRC with the
opportunity to develop and deploy a multiple independently-targetable reentry vehicle
(MIRV) should it decide to do so. These smaller designs would allow the use of lighter and
faster reentry vehicles that may be better able to stress and to overcome ballistic
The PRC has expressed considerable opposition to U.S. deployment of ballistic missile
Other advantages of increased warhead yield-to-weight ratios include extended missile
ranges and accuracy improvements. Smaller warheads result in a more compact missile
payload, extending the range of ballistic missiles. This permits the use of
smaller-diameter sea-launched ballistic missiles and mobile missiles to strike long-range
targets. Longer range could enable PRC ballistic missile submarines to strike the U.S.
from within PRC waters, where they can operate safely.
Multiple Warhead Development
The deployment of multiple warheads on a single missile requires smaller warheads that
the PRC has not possessed.
The Select Committee has no information on whether the PRC currently intends to develop
and deploy multiple independently targetable reentry vehicle systems. However, the Select
Committee is aware of reports that the PRC has undertaken efforts related to multiple
Experts believe that the PRC currently has the technical capability to develop and
deploy silo-based ballistic missiles with multiple reentry vehicles (MRVs) and multiple
independently-targetable reentry vehicles (MIRVs). Experts also agree that the PRC could
develop and deploy its new generation of mobile intercontinental ballistic missiles with
MRVs or MIRVs within a short period of years after a decision to do so, and consistent
with the presumed timeframe for its planned deployment of its next-generation
intercontinental ballistic missiles.
The PRC is one of the world's leading proliferators of weapons technologies. Concerns
about the impact of the PRC's thefts of U.S. thermonuclear warhead design information,
therefore, include the possible proliferation of the world's most sophisticated nuclear
weapons technology to nations hostile to the United States.
Russian Assistance to the PRC's Nuclear Weapons Program
After the fall of the Soviet Union, the PRC and Russian scientists became increasingly
cooperative in civilian nuclear technology, and apparently, military technology. The
Select Committee is concerned that the growing cooperation between Russia and the PRC is
an indication of current or future nuclear weapons cooperation. The Select Committee
judges that Russia's nuclear weapons testing technology and experience could significantly
assist the PRC with its nuclear weapons program under the Comprehensive Test Ban Treaty,
which does not permit physical testing.
While the PRC could share its knowledge of U.S. advanced thermonuclear warhead designs
with Russia, Russia may not be interested in deviating from its past developmental path,
since existing Russian warhead designs are apparently simple and reliable. The large
throw-weight of Russian ballistic missiles has given them less cause for concern about the
size and weight of their warheads. Russia's nuclear stockpile maintenance requirements
under a Comprehensive Test Ban Treaty are thus very different than those of the United
The prospect of PRC-Russian cooperation, if that were to include military cooperation,
would give rise to concerns in several areas, including nuclear weapons development and
nuclear stockpile maintenance, nuclear weapons modeling and simulation, and nuclear
weapons testing data.
How the PRC Acquired Thermonuclear Warhead Design Information from the United States:
PRC Espionage and Other PRC Techniques
The Select Committee judges that the PRC's intelligence collection efforts to develop
modern thermonuclear warheads have focused primarily on the following U.S. National
Laboratories: Los Alamos, Lawrence Livermore, Oak Ridge, and Sandia. These efforts
included espionage, rigorous review of U.S. unclassified technical and academic
publications, and extensive interaction with U.S. scientists and Department of Energy
Espionage played a central part in the PRC's acquisition of classified U.S.
thermonuclear warhead design secrets. In several cases, the PRC identified lab employees,
invited them to the PRC, and approached them for help, sometimes playing upon ethnic ties
to recruit individuals.
The PRC also rigorously mined unclassified technical information and academic
publications, including information from the National Technical Information Center and
other sources. PRC scientists have even requested reports via e-mail from scientists at
the U.S. national weapons laboratories. Peter Lee, who had been a scientist at both
Lawrence Livermore and Los Alamos National Laboratories and was convicted in 1997 of
passing classified information to the PRC, gave the PRC unclassified technical reports
upon request. The PRC also learned about conventional explosives for nuclear weapon
detonation from reviewing unclassified technical reports published by Department of Energy
national weapons laboratories.
PRC scientists have used their extensive laboratory-to-laboratory interactions with the
United States to gain information from U.S. scientists on common problems, solutions to
nuclear weapons physics, and solutions to engineering problems. The PRC uses elicitation
in these meetings, where it shows familiarity with U.S. information in an effort to
"prime the pump" in order to try to glean information about U.S. designs. U.S.
scientists have passed information to the PRC in this way that is of benefit to the PRC's
nuclear weapons program.
Specific examples of the loss of classified U.S. information in this manner are
detailed in the Select Committee's classified Final Report. The Clinton administration has
determined that these examples cannot be publicly discussed.
The PRC's espionage operations, which use traditional intelligence gathering
organizations as well as other entities, are aggressively focused on U.S. weapons
The PRC's Academy of Engineering Physics (CAEP), which is under the Commission of
Science, Technology, and Industry for National Defense (COSTIND), is the entity in charge
of the PRC's nuclear weapons program. It is responsible for the research and development,
testing, and production of all of the PRC's nuclear weapons. The figure below shows the
organization of the PRC's nuclear infrastructure.5
The China Academy of Engineering Physics has pursued a very close relationship with
U.S. national weapons laboratories, sending scientists as well as senior management to Los
Alamos and Lawrence Livermore. Members of the China Academy of Engineering Physics senior
management have made at least two trips during the mid-to-late 1990s to U.S. national
weapons laboratories to acquire information and collect intelligence. These visits provide
the opportunity for the PRC to collect intelligence. The presence of such PRC nationals at
the U.S. national weapons laboratories facilitates the PRC's targeting of U.S. weapons
scientists for the purpose of obtaining nuclear weapons information.
U.S. and PRC lab-to-lab exchanges were ended in the late 1980s, but were resumed in
1993. Scientific exchanges continue in many areas including high-energy physics.6
Discussions at the U.S. national weapons laboratories in connection with the foreign
visitors program are supposed to be strictly limited to technical arms control and
material accounting issues. Nonetheless, these visits and scientific conferences provide
opportunities for the PRC to interact with U.S. scientists outside of official meetings,
and facilitate the PRC's targeting of U.S. weapons scientists.
The U.S. national weapons laboratories argue that there are reciprocal gains from the
exchanges. The Department of Energy describes some of the insights gained from these
exchanges as unique. On the other hand, PRC scientists have misled the U.S. about their
objectives and technological developments. Despite considerable debate in Congress and the
Executive branch, including several critical Government Accounting Office reports, the
U.S. Government has never made a definitive assessment of the risks versus the benefits of
scientific exchanges and foreign visitor programs involving the U.S. national weapons
How the U.S. Government Learned of the PRC's Theft of Our Most Advanced
Thermonuclear Warhead Design Information
The U.S. Government did not become fully aware of the magnitude of the
counterintelligence problems at the Department of Energy laboratories until 1995. The
first indication of successful PRC espionage against the laboratories arose in the late
1970s. During the last several years, more information has become available concerning
thefts of U.S. thermonuclear warhead design information, and how the PRC may be exploiting
it. A series of PRC nuclear tests conducted from 1992 to 1996 that furthered the PRC's
development of advanced warheads led to suspicions in the U.S. intelligence community that
the PRC had stolen advanced U.S. thermonuclear warhead design information.
In 1995, a "walk-in" approached the Central Intelligence Agency outside of
the PRC and provided an official PRC document classified "Secret" that contained
design information on the W-88 Trident D-5 warhead, the most modern in the U.S. arsenal,
as well as technical information concerning other thermonuclear warheads.
The CIA later determined that the "walk-in" was directed by the PRC
intelligence services. Nonetheless, the CIA and other Intelligence Community analysts that
reviewed the document concluded that it contained U.S. thermonuclear warhead design
The "walk-in" document recognized that the U.S. nuclear warheads represented
the state-of-the-art against which PRC thermonuclear warheads should be measured.
Espionage Definition of a "Walk-In"
A "walk-in" is an individual who voluntarily offers to conduct espionage. The
Encyclopedia of Espionage defines a "walk-in" as "an unheralded defector or
a dangle, a Ôwalk-in' is a potential agent or a mole who literally walks into an embassy
or intelligence agency without prior contact or recruitment." See the Spy Book, The
Encyclopedia of Espionage, by Norman Polmar and Thomas B. Allen (RH Reference &
Information Publishing, Random House).
The individual who approached the CIA in 1995 is suspected of being a "directed
walk-in": a "walk-in" purposefully directed by the PRC to provide this
information to the United States. There is speculation as to the PRC's motives for
advertising to the United States the state of its nuclear weapons development.
Over the following months, an assessment of the information in the document was
conducted by a multidisciplinary group from the U.S. Government, including the Department
of Energy and scientists from the U.S. national weapons laboratories. The Department of
Energy and FBI investigations focused on the loss of the U.S. W-88 Trident D-5 design
information, but they did not focus on the loss of technical information about the other
five U.S. thermonuclear warheads. A Department of Energy investigation of the loss of
technical information about the other five U.S. thermonuclear warheads had not begun as of
January 3, 1999, after the Select Committee had completed its investigation. Also, the FBI
had not yet initiated an investigation as of January 3, 1999.
The PRC's Future Thermonuclear Warhead Requirements: The PRC's Need for Nuclear Test
Data and High Performance Computers
Since signing the Comprehensive Test Ban Treaty (CTBT) in 1996, the PRC has faced new
challenges in maintaining its modern thermonuclear warheads without physical testing.
Indeed, even after signing the CTBT, the PRC may be testing sub-critical or low yield
nuclear explosive devices underground at its Lop Nur test site.
The PRC likely does not need additional physical tests for its older thermonuclear
warhead designs. But maintenance of the nuclear weapons stockpile for these weapons does
require testing. The ban on physical testing to which the PRC agreed in 1996 has therefore
increased the PRC's interest in high performance computing and access to sophisticated
computer codes to simulate the explosion of nuclear weapons.8
The Select Committee judges that the PRC has likely developed only a very modest
complement of codes from inputting its own testing data into high performance computers.
The PRC would, therefore, be especially interested in acquiring U.S. thermonuclear weapons
codes for any new weapons based on elements of stolen U.S. design information.
The Department of Energy reports that the PRC has in fact acquired some U.S. computer
codes, including: the MCNPT code; the DOT3.5 code; and the NJOYC code.9 MCNPT is a
theoretical code that is useful in determining survivability of systems to electronic
penetration and dose penetration in humans. DOT3.5 is a two-dimensional empirical code
that performs the same kinds of calculations as MCNPT, except uses numerical integration.
NJOYC acts as a numerical translator between DOT3.5 and MCNPT.
Given the limited number of nuclear tests that the PRC has conducted, the PRC likely
needs additional empirical information about advanced thermonuclear weapon performance
that it could obtain by stealing the U.S. "legacy" computer codes, such as those
that were used by the Los Alamos National Laboratory to design the W-88 Trident D-5
warhead. The PRC may also need information about dynamic three-dimensional data on warhead
packaging, primary and secondary coupling, and the chemical interactions of materials
inside the warhead over time.
The Select Committee is concerned that no procedures are in place that would either
prevent or detect the movement of classified information, including classified
nuclear-weapons design information or computer codes, to unclassified sections of the
computer systems at U.S. national weapons laboratories. The access granted to individuals
from foreign countries, including students, to these unclassified areas of the U.S.
national weapons laboratories' computer systems could make it possible for others acting
as agents of foreign countries to access such information, making detection of the persons
responsible for the theft even more difficult.
The Select Committee believes that the PRC will continue to target its collection
efforts not only on Los Alamos National Laboratory, but also on the other U.S. National
Laboratories involved with the U.S. nuclear stockpile maintenance program.
The PRC may also seek to improve its hydrostatic testing capabilities by learning more
about the Dual-Axis Radiographic Hydrotest (DARHT) facility at Los Alamos.
U.S. Government Investigations of Nuclear Weapons Design Information Losses
Investigation of Theft of Design Information for the Neutron Bomb
The Select Committee received information about the U.S. Government's investigation of
the PRC's theft of classified U.S. design information for the W-70 thermonuclear warhead.
The W-70, which is an enhanced radiation nuclear warhead (or "neutron bomb"),
also has elements that can be used for a strategic thermonuclear warhead. In 1996 the U.S.
Intelligence Community reported that the PRC had successfully stolen classified U.S.
technology from a U.S. Nuclear Weapons Laboratory about the neutron bomb.
This was not the first time the PRC had stolen classified U.S. information about the
neutron bomb. In the late 1970s, the PRC stole design information on the U.S. W-70 warhead
from Lawrence Livermore Laboratory. The U.S. Government first learned of this theft
several months after it took place. The PRC subsequently tested a neutron bomb in 1988.
The FBI developed a suspect in the earlier theft. The suspect worked at Lawrence
Livermore National Laboratory, and had access to classified information including designs
for a number of U.S. thermonuclear weapons in the U.S. stockpile at that time.
In addition to design information about the W-70, this suspect may have provided to the
PRC additional classified information about other U.S. weapons that could have
significantly accelerated the PRC's nuclear weapons program.
The Clinton administration has determined that further information about these thefts
cannot be publicly disclosed.
Investigation of Thefts of Information Related to the Detection of Submarines and of
Laser Testing of Miniature Nuclear Weapons Explosions
Peter Lee is a naturalized U.S. citizen who was born in Taiwan. Lee worked at Los
Alamos National Laboratory from 1984 to 1991, and for TRW Inc., a contractor to Lawrence
Livermore National Laboratory, from 1973 to 1984 and again from 1991to 1997.10
Lee has admitted to the FBI that, in 1997, he passed to PRC weapons scientists
classified research into the detection of enemy submarines under water. This research, if
successfully completed, could enable the PLA to threaten previously invulnerable U.S.
Lee made the admissions in 1997 during six adversarial interviews with the FBI.
According to Lee, the illegal transfer of this sensitive research occurred while he was
employed by TRW, Inc., a contractor for the Lawrence Livermore National Laboratory. The
classified U.S.information was developed by Lawrence Livermore as part of a joint United
States-United Kingdom Radar Ocean Imaging project for anti-submarine warfare applications.
Specifically, on or about May 11, 1997, Lee gave a lecture in Beijing at the PRC
Institute of Applied Physics and Computational Mathematics (IAPCM). Among the attendees
were nuclear weapons scientists from the IAPCM and the China Academy of Engineering
Lee described for the PRC weapons scientists the physics of microwave scattering from
ocean waves. Lee specifically stated that the purpose of the research was anti-submarine
At one point in his presentation, Lee displayed an image of a surface ship wake, which
he had brought with him from the United States. He also drew a graph and explained the
underlying physics of his work and its applications. He told the PRC scientists where to
filter data within the graph to enhance the ability to locate the ocean wake of a vessel.
Approximately two hours after his talk was over, Lee erased the graph and tore the ship
wake image "to shreds" upon exiting the PRC institute.11
In 1997, the decision was made to not prosecute Lee for passing this classified
information on submarine detection to the PRC. Because of the sensitivity of this area of
research, the Defense Department requested that this information not be used in a
Throughout much of the l990s, the FBI conducted a multi-year investigation of Peter
Lee, employing a variety of techniques, but without success in collecting incriminating
evidence. Finally, in 1997, Lee was charged with willfully providing to the PRC classified
information on techniques for creating miniature nuclear fusion explosions.
Specifically, Lee explained to PRC weapons scientists how deuterium and tritium can be
loaded into a spherical capsule called a target and surrounded by a hohlraum, and then
heated by means of laser bombardment. The heat causes the compression of these elements,
creating a nuclear fusion micro-explosion. This so-called "inertial confinement"
technique permits nuclear weapons scientists to study nuclear explosions in
miniature--something of especial usefulness to the PRC, which has agreed to the ban on
full-scale nuclear tests in the Comprehensive Test Ban Treaty.
Lee's admission that he provided the PRC with this classified information about nuclear
testing using miniaturized fusion explosions came in the course of the same 1997
adversarial FBI interviews that yielded his admission of passing submarine detection
research to the PRC. Lee's delivery of the miniature nuclear testing information to the
PRC occurred in 1985, while he was employed as a researcher at Los Alamos National
Lee said that during a lecture in the PRC he answered questions and drew diagrams about
hohlraum construction. In addition, Lee is believed to have provided the PRC with
information about inertial confinement lasers that are used to replicate the coupling
between the primary and secondary in a thermonuclear weapon.
Lee was formally charged with one count of "gathering, transmitting or losing
defense information," in violation of Section 793 of Title 18 of the U.S. Code, and
one count of providing false statements to a U.S. government agency, in violation of
Section 1001, Title 18. On December 8, 1997, Lee pled guilty to willfully passing
classified U.S. defense information to PRC scientists during his 1985 visit to the PRC.
Lee also pled guilty to falsifying reports of contact with PRC nationals in 1997.
Lee was sentenced to 12 months in a halfway house, a $20,000 fine and 3,000 hours of
The Select Committee judges that, between 1985 and 1997, Lee may have provided the PRC
with more classified thermonuclear weapons-related information than he has admitted.
The PRC apparently co-opted Lee by appealing to his ego, his ethnicity, and his sense
of self-importance as a scientist.
Investigation of Theft of Design Information For the W-88 Trident D-5 Thermonuclear
The Select Committee received information about the U.S. Government's ongoing
investigation of the loss of information about the W-88 Trident D-5 thermonuclear warhead
During the PRC's 1992 to 1996 series of advanced nuclear weapons tests, a debate began
in the U.S. Government about whether the PRC had acquired classified U.S. thermonuclear
weapons design information. The Department of Energy began to investigate. In 1995,
following the CIA's receipt of evidence (provided by the PRC-directed "walk-in")
that the PRC had acquired technical information on a number of U.S. thermonuclear
warheads, including not only the W-88 Trident D-5 but five other warheads as well, the
Department of Energy's investigation intensified. That investigation, however, focused on
the W-88 and not the other weapons.
Early in its investigation, the Department of Energy cross-referenced personnel who had
worked on the design of the W-88 with those who had traveled to the PRC or interacted with
PRC scientists. One individual who had hosted PRC visitors in the past emerged from this
inquiry as a suspect by the spring of 1995.
Even after being identified as a suspect, the individual, who still had a security
clearance, continued to work in one of the most sensitive divisions at Los Alamos National
Laboratory, Division X, which handles thermonuclear weapons designs and computer codes. In
this position, the suspect requested and received permission to hire a PRC graduate
student who was studying in the U.S. for the summer.
In December 1998, the suspect traveled to Taiwan. Following his return from Taiwan in
December 1998, he was removed from Division X.
The FBI initiated a full investigation in the middle of 1996, which remains ongoing. At
the date of this report, the suspect continues to work at the Los Alamos National
Laboratory, and continues to have access to classified information.
The FBI investigation of this suspect's possible involvement in the theft of classified
design information on the W-88 warhead and other matters is ongoing.
The Clinton administration has determined that further information on this matter
cannot be disclosed publicly.
Investigation of Additional Incidents
The Select Committee reviewed one case that offers a troublesome example of the manner
in which scientific exchanges in the PRC can be exploited for espionage purposes. The
incident involved the inadvertent, bordering on negligent, disclosure of classified
technical information by a U.S. scientist lecturing in the PRC.
The U.S. scientist, who was representing a U.S. National Laboratory during a lab-to-lab
exchange with a PRC laboratory, was pressured by PRC counterparts to provide a solution to
a nuclear weapons-related problem. Rather than decline, the scientist, who was aware of
the clear distinction between the classified and unclassified technical information that
was under discussion, provided an analogy. The scientist immediately saw that the PRC
scientists had grasped the hint that was provided and realized that too much had been
The PRC employs various approaches to co-opt U.S. scientists to obtain classified
information. These approaches include: appealing to common ethnic heritage; arranging
visits to ancestral homes and relatives; paying for trips and travel in the PRC;
flattering the guest's knowledge and intelligence; holding elaborate banquets to honor
guests; and doggedly peppering U.S. scientists with technical questions by experts,
sometimes after a banquet at which substantial amounts of alcohol have been consumed.
On average, the FBI has received about five security-related referrals each month from
the Department of Energy. Not all of these concern the PRC. These referrals usually
include possible security violations and the inadvertent disclosure of classified
The FBI normally conducts investigations of foreign individuals working at the National
The Clinton administration has determined that additional information in this section
cannot be publicly disclosed.
The Department of Energy's Counterintelligence Program at the U.S. National Weapons
With additional funds provided by Congress in 1998, the Department of Energy is
attempting to reinvent its counterintelligence programs at the U.S. national weapons
laboratories to prevent continued loss of information to the PRC's intelligence collection
Funding for the Department of Energy's counterintelligence program, including seven
employees at the Department of Energy's headquarters, was $7.6 million in Fiscal Year
1998. For Fiscal Year 1999, Congress has increased that amount to $15.6 million.
With the support of the Director of Central Intelligence and the Director of the
Federal Bureau of Investigation, the President issued Presidential Decision Directive 61
(PDD-61) in February 1998. PDD-61 requires that a senior FBI counterintelligence agent be
placed in charge of the Department of Energy's program, which has been done.
PDD-61 also instructed that a counterintelligence report with recommendations be
presented to the Secretary of Energy. The report was submitted to the Secretary on July 1,
1998, with 33 specific recommendations. The Secretary had 30 days to respond to the
National Security Council. However, due to the transition from Secretary Pena to Secretary
Richardson, the response was delayed. In late November 1998, the Secretary of Energy
approved all substantive recommendations. In December 1998, the Directors of the U.S.
National Laboratories agreed to the counterintelligence plan during a meeting with the
Secretary of Energy. The Department of Energy is now implementing the plan.
The Secretary's action plan instructs the Directors of the U.S. National Laboratories
to implement the recommendations. It directs the Department of Energy's Office of
Counterintelligence to fund counterintelligence positions at individual laboratories so
that they work directly for the Department of Energy, not the contractors that administer
The Department of Energy will create an audit trail to track unclassified computer use
and protect classified computer networks. The action plan also directs the creation of
counterintelligence training programs and a counterintelligence analysis program.
The Department of Energy will also implement stricter requirements for reporting all
interactions with foreign individuals from sensitive countries, including correspondence
by e-mail. Laboratory Directors will be responsible for scrutinizing foreign visitors, in
coordination with Department of Energy's Counterintelligence Office.
The Department of Energy will require counterintelligence polygraphs of those who work
in special access programs (SAP) and sensitive areas with knowledge of nuclear weapons
design, or actually have hands-on access to nuclear weapons (about 10 percent of the total
cleared population within the Department of Energy). Such persons will also undergo
financial reviews and more rigorous background investigations conducted through local
field offices of the FBI.
The FBI reportedly has sent several agents to the Department of Energy in the last 10
years to try to improve the counterintelligence program, but has repeatedly been
unsuccessful. A significant problem has been the lack of counterintelligence
professionals, and a bureaucracy that "buried" them and left them without access
to senior management or the Secretary of Energy. The Department of Energy's new
Counterintelligence Director now has direct access to the Secretary.
After traveling to the laboratories and interviewing counterintelligence officials, the
Department of Energy's new Counterintelligence Director reported in November 1998:
The counterintelligence program at DOE [the Department of Energy] does not even meet
minimal standards ... there is not a counterintelligence [program], nor has there been one
at DOE [the Department of Energy] for many, many years.
The Department of Energy's counterintelligence program requires additional training,
funding, and accountability, according to this counterintelligence official.
At present, the Department of Energy's background investigations are conducted by an
Office of Personnel Management contractor. The new Director's opinion is that the present
background investigations are "totally inadequate" and "do [not] do us any
Another problem area is that the Department of Energy's counterintelligence process
presently does not have any mechanism for identifying or reviewing the thousands of
foreign visitors and workers at the U.S. national weapons laboratories. On one occasion
reviewed by the Select Committee, for example, scientists from a U.S. National Laboratory
met foreign counterparts in a Holiday Inn in Albuquerque, New Mexico, in order to
circumvent their laboratory's security procedures.
One responsibility of the Department of Energy's new counterintelligence program will
be to find out who visits the laboratories, including those from sensitive countries, what
they work on while they visit, and whether their access is restricted to protect
classified information. Mechanisms have been recommended to identify visitors and fully
vet them. The Department of Energy will attempt to improve the database used for
Classified information has been placed on unclassified networks, with no system for
either detection or reliable prevention. There are no intrusion detection devices to
determine whether hackers have attacked the Department of Energy's computer network.
According to damage assessments reviewed by the Select Committee, however, attacks on the
computers at the U.S. national weapons laboratories are a serious problem. E-mail is also
a threat: the U.S. national weapons laboratories cannot track who is communicating with
whom. For example, over 250,000 unmonitored e-mails are sent out of the Sandia National
Laboratory alone each week.
In the year 2000, the Department of Energy will concentrate on increasing its
analytical and investigative capabilities. Until at least the year 2000, the Department of
Energy's counterintelligence program will not be adequate.
The five U.S. National Laboratories (Lawrence Livermore, Los Alamos, Oak Ridge, Sandia,
and Pacific Northwest) are the primary focus of the counterintelligence plan. The
Department of Energy is hiring senior counterintelligence experts who will report directly
to the Directors of these laboratories.
Many of the specific recommendations in the Presidential Decision Directive are not
new, and similar changes have been attempted unsuccessfully before.
Notification of the President and Senior U.S. Officials
In response to interrogatories from the Select Committee, the National Security Advisor
testified in writing that the President did not learn about the issue of successful PRC
espionage at the U.S. national weapons laboratories and long-term counterintelligence
problems at the Department of Energy until early 1998.14
The Department of Energy briefed the Secretary of Energy about the matter in late 1995
and early 1996.
The Department of Energy first briefed the Deputy National Security Advisor in April
The Department of Energy briefed the Director of Central Intelligence, the Director of
the FBI, the Secretary of Defense, and the Attorney General during this period.
The Department of Energy has not briefed the Secretary of State or the Secretary of
Commerce. The Congress was not fully briefed until late 1998, as a result of the efforts
of the Select Committee.
PRC Theft Endnotes
1 The Select Committee believes that nuclear tests related to the development of the
PRC's next generation of thermonuclear warheads may be continuing underground at the PRC
test site at Lop Nur.
2 "Chinese Nuclear Testing and Warhead Development," Jonathan Medalia,
Congressional Research Service, November 14, 1997.
4 Figure 3 - Size Comparison of U.S. Nuclear Warheads Over Time, Lawrence Livermore
National Laboratory, September 15, 1998.
5 "Presentation on PRC, Nuclear Weapons and High Performance Computing ,"
Lawrence Livermore National Laboratory, September 15,1998.
6 Premier Zhu Rongji recently praised the efforts and progress of PRC and U.S.
scientists who attended the 19th Meeting of the Sino-U.S. Joint Committee on High Energy
Physics. Reportedly, Zhu expressed pleasure that the "two nations have conducted
wide-ranging in-depth exchanges during the meeting and put forward many helpful proposals,
which will not only be conducive to the development of high energy physics in PRC and the
U.S., but also help expand scientific and technological cooperation between the two
countries." An area of concern is the PRC intelligence practice of mining even
ostensibly cooperative scientific exchanges for useful information. "Premier Meets
U.S. Science Group," China Daily, November 18, 1998.
7 See Major Weaknesses in Foreign Visitor Controls at Weapons Laboratories, Government
Accounting Office, October 1988; DOE Needs to Improve Controls Over Foreign Visitors to
Weapons Laboratories, Government Accounting Office, September 1997; and, DOE Needs to
Improve Controls Over Foreign Visitors To Its Weapons Laboratories, Government Accounting
Office, October 14, 1998.
8 See this report's high performance computer chapter for additional information about
the PRC's interests in this area, and the linkage between modern nuclear development and
the importance of high performance computing, especially for stockpile maintenance under a
Comprehensive Test Ban Treaty.
9 "Presentation on PRC, Nuclear Weapons and High Performance Computing ,"
Lawrence Livermore National Laboratory, September 15, 1998.
10 The Department of Energy conducted a damage assessment of the Peter Lee losses that
the Select Committee requested to review but did not receive.
11 Government's Response to Defendant's Position With Respect to Sentencing Factors:
Declarations of Jonathan Shapiro: Attachments (U.S.D.C. C.D. Calif.) March 24, 1998.
12 Letter from FBI Director Louis Freeh to Chairman Christopher Cox and Ranking Member
Norman Dicks, November 10, 1998. Peter Lee refused to cooperate with the Select
Committee's investigation on the advice of his lawyer not to testify before, or provide
information to, the Select Committee.
13 "Response to November 12 Letter Seeking Assistance in Providing Briefings
Concerning the President's Knowledge of Several Subjects," Letter from Samuel Berger,
Assistant to the President for National Security Affairs to Chairman Christopher Cox and
Ranking Member Norman Dicks, December 22, 1998. Samuel (Sandy) R. Berger, National
Security Advisor, originally told the Select Committee that he briefed President Clinton
about the theft of U.S. nuclear information in early 1998. Later, in May 1999, as part of
the declassification process to make this report publicly available, Berger advised the
Select Committee that the President was briefed in July 1997, although no written record
of this meeting exists.