Since their introduction at the end of World War II, nuclear weapons have been seen as so
radically different from other weaponry, so uniquely destructive, that extraordinary measures are
needed to slow their spread. To this end, Congress enacted the Atomic Energy Act to assure firm
government control over all aspects of nuclear technology relating to the creation, design,
production, or use of nuclear weapons. An important element of this control is the Restricted
Data (RD) system, established by the Act to secure nuclear weapons-related information by
providing it with a unique system of classification. RD is defined by section 11y of the Act:
The term "Restricted Data" means all data concerning (1) design, manufacture, or utilization of atomic weapons; (2) the production of special
nuclear material; or (3) the use of special nuclear material in the production
of nuclear energy; but shall not include data declassified or removed from the
Restricted Data category pursuant to section 142.
This statute-based system operates outside of the National Security Information (NSI) system
established by Executive order for all other Government classified information.
RD is specifically exempted from all provisions of E.O. 12958. In particular, RD is never subject
to automatic declassification but can only be declassified by the Secretary of Energy or delegated
DOE authority. RD is generally technical. Some of it has enduring value so long as it is not
compromised. In the hands of an adversary, a nuclear weapon based on a 40-year-old design
could be as great a threat as a modern weapon.
This Appendix is intended to aid the document reviewer in detecting the possible presence
of classified nuclear information in NSI classified documents, which may be improperly
marked, to reflect the presence of either RD or Formerly Restricted Data (FRD), which
despite the name is classified but deals with military utilization of nuclear weapons. Much
information that was once RD or FRD has been declassified over the years. Therefore,
information fitting the descriptions or containing key words provided below is not necessarily
classified as RD or FRD but should be referred to DOE for review and final determination.
Information classified as RD or FRD is likely to be found in documents dealing with any of the
following areas:
- Nuclear weapon design, fabrication, and utilization
- Nuclear weapons apply the
physical phenomenon of nuclear fission -- the splitting of a heavy atomic nucleus (uranium and/or
plutonium) by absorption of a neutron -- to cause the release of explosive energy ("yield") many
orders of magnitude greater than would be possible from a similar amount of ordinary high
explosives. Some nuclear weapons also use the process of thermonuclear fusion -- the joining
together of light nuclei at very high temperatures -- to produce additional yield by "boosting" the
fission explosion with extra neutrons, or in a separate thermonuclear "stage" (e.g., the "hydrogen
bomb"). Information revealing weapon configurations, design principles and details, mode of
operation, tests, yields, methods for command/control, disablement, vulnerabilities to sabotage or
countermeasures, and storage or deployment locations may be and usually is classified. RD or
FRD (but not bearing RD or FRD markings) is perhaps most likely to be found in NSI documents
dealing with weapon delivery systems such as missiles or aircraft, or with defense against such
systems.
- Inertial confinement fusion
- This laboratory-scale research attempts to use
certain directed power sources -- typically very large lasers, but also accelerator-produced
particle beams -- to compress and heat a tiny target containing small quantities of fusion
fuel (deuterium and tritium) to thermonuclear ignition conditions. The resulting "microexplosion"
would resemble a miniaturized thermonuclear weapon. Therefore, target design and operation
information judged to be particularly revelatory of related nuclear weapons technology is classified.
- Military nuclear reactors
- Nuclear reactors use the fission reaction to generate energy
for conversion to electric power or other application, but in a much slower, controlled manner
than occurs in a nuclear explosion. Information in this area will include design, development, test,
and operation of reactor power systems for military purposes, especially for naval nuclear
propulsion, and information concerning capabilities and vulnerabilities. The emphasis here is on
"military" or "naval," since all aspects of civilian nuclear power (e.g., commercial electric power
generation) are unclassified.
- Nuclear material production
- The most certain way to discourage the proliferation of
nuclear weapons is to deny access to fissile materials such as plutonium or enriched uranium.
Plutonium does not occur naturally in any significant quantity, but must be produced in nuclear
reactors designed especially for this purpose. The unstable hydrogen isotope tritium, required for
boosting fission weapons, is also made in such reactors. Information describing detailed features
of the production process may be RD. Fuel reprocessing, in which the spent reactor fuel is put
through a sequence of chemical operations to extract the product plutonium, is an important part
of the production process.
- Isotope separation
- Unlike plutonium, uranium occurs naturally and is relatively plentiful.
However, only the lighter isotope U-235 (0.7% of the natural element) is useful for a fission
explosion using thermal neutrons. Extracting this isotope from natural uranium requires a process
that can separate the U-235 from the slightly heavier but much more common isotope U-238.
This has been done by diffusion techniques, which exploit slight thermal speed differences
between gas molecules containing the different isotopes; by electromagnetic and centrifuge
techniques, which exploit the difference in inertial mass; and by laser separation techniques, which
exploit isotopic differences in atomic spectra. Potentially classified information includes process
and design details of these different isotope separation methods, and the amounts and
specifications of material prepared for the weapons program.
- Atomic or nuclear device, weapon, explosive, or warhead
- anti-tampering device
- boosted, boosting
- channel, radiation channel
- D-T gas
- deployments
- detonator, detonation system
- deuterium, (D, 2 H)
- dial-a-yield, selectable yields
- dimensions, weights
- disablement, command disablement
- enhanced radiation
- Fat Man (Trinity test, Nagasaki combat drop)
- firing set
- fission
- fusion, thermonuclear fusion
- gun-assembled
- height-of-burst
- highly enriched uranium (HEU)
- hydrogen weapon, hydrogen bomb
- hydronuclear experiment, test
- implosion
- initiator, initiation, pre-initiation
- insensitive high explosive (IHE)
- interstage coupling
- interval time
- Joint Task Force (JTF)
- limited-life component
- lithium, lithium deuteride
- Little Boy (Hiroshima combat drop)
- neutron generator
- nuclear test, test series
- one-point safe
- oralloy
- permissive action link, PAL
- pit, sealed pit
- Plowshare Program
- plutonium (Pu), weapon-grade plutonium
- primary
- Project Matterhorn
- Project Whitney
- pusher
- radiation flow
- radiation implosion
- radiation case
- release codes
- reservoir, gas reservoir
- safing
- salvage fuze
- scaled depth of burial (SDOB)
- secondary
- staged, second stage
- stockpile
- tamper
- Trinity
- tritium (T, 3 H)
- tuballoy
- uranium
- weapons-grade [material]
- X-unit
- yield (kilotons, megatons)
- yield-to-weight
- Weapon configurations
- Schematic depictions of nuclear weapons may be found in NSI documents that are lacking
RD markings. Figures likely to be encountered will resemble either a single circle (have
one center) for single stage weapons, or two adjacent circles (i.e., two centers of
symmetry) for a staged or thermonuclear weapon. This is only a rough characterization.
Weapons schematics would be considered RD.
- Nuclear weapon outputs and effects
- blackout, radar blackout
- damage radius
- effects test
- electromagnetic pulse (EMP)
- enhanced radiation
- fallout
- fireball
- gamma radiation
- hardening
- line-of-sight pipe
- neutron, neutron radiation, neutron spectrum
- radiation, especially prompt radiation or radiation dose
- radiochemical tracer
- tailored outputs
- vulnerability
- x-ray spectrum
- Inertial confinement fusion (ICF)
- direct drive
- hohlraum
- ICF target
- indirect drive
- laser fusion
- particle-beam (light ion, heavy ion) fusion
- Military nuclear reactors
- quieting
- directed nuclear energy
- naval reactors
- naval nuclear propulsion
- space nuclear power
- Reactor Production of special nuclear materials (SNM)
- fuel reprocessing
- Hanford reactors
- N-reactor
- plutonium production
- production reactor
- PUREX process
- Savannah River reactors
- tritium production
- Isotope separation
- atomic vapor laser isotope separation (AVLIS)
- cascade
- deuterium production
- diffuser
- diffusion barrier
- electromagnetic separation -- Calutron
- enrichment
- gas centrifuge
- gaseous diffusion
- laser isotope separation
- lithium enrichment
- molecular laser isotope separation (MLIS)
- thermal diffusion
- uranium hexafluoride
- uranium enrichment
U.S. nuclear weapons have been designed at the Los Alamos, Livermore, and Sandia
Laboratories, and manufactured in a production complex that has changed with time but always
been spread over the United States. Key sites and organizations that may be found in conjunction
with nuclear information and potential RD:
- Albuquerque Operations Office (ALO)
- ACF Industries
- Air Force Office - Atomic Testing (AFOAT)
- Air Force Special Weapons Center (AFSWC)
- Air Force Technical Applications Center (AFTAC)
- Amchitka
- Armed Forces Special Weapons Project (AFSWP)
- Assistant to the Secretary of Defense, Atomic Energy (ATSD-AE)
- Atomic Energy Act (AEA)
- Atomic Energy Commission (AEC)
- Atomic Weapons Establishment (AWE), UK
- Atomic Weapons Research Establishment (AWRE), UK
- Bendix Kansas City
- Bethe Panel
- Bettis Atomic Power Laboratory
- Bikini, Bikini atoll
- Burlington Industries
- Christmas Island
- Defense Atomic Support Agency (DASA)
- Defense Threat Reduction Agency (DTRA)
- Division of Military Application (DMA)
- Energy Research and Development Administration (ERDA)
- Eniwetok, Enewetak
- Fernald
- GE Pinellas
- Hanford
- Hiroshima
- Johnston Island
- Joint Committee on Atomic Energy (JCAE)
- Knolls Atomic Power Laboratory
- Lawrence Radiation Laboratory (LRL)
- Lawrence Livermore National Laboratory (LLNL)
- Los Alamos National Laboratory (LANL)
- Los Alamos Scientific Laboratory (LASL)
- Manhattan Project, Manhattan Engineering District
- Military Liaison Committee
- Mound Laboratories
- Nagasaki
- Nevada Operations Office (NVO)
- Nevada Test Site (NTS)
- Nuclear weapons complex
- Oak Ridge Y-12
- Oak Ridge K-25
- Pacific Test Range
- Pantex
- Paducah Site or Gaseous Diffusion Plant
- Pittsburgh Naval Reactors Office
- Portsmouth Site or Gaseous Diffusion Plant
- Richland
- Rocky Flats
- Sandia National Laboratory (SNL)
- Sandia Laboratories (SL)
- Savannah River
- University of California Radiation Laboratory (UCRL)
The markings listed below would indicate that the document may contain RD or FRD, even if not
otherwise marked:
- Atomal (NATO)
- ATOMIC (UK)
- Cosmic (NATO)
- Critical Nuclear Weapon Design Information (CNWDI)
- NNPI (Naval Nuclear Propulsion Information)
- Protect as Restricted Data (PARD)
- Sigma [n], where n is a number
- Weapon Data
If the reviewer, using the information provided above, suspects that a NSI classified document
may contain RD/FRD, the document should be marked
"MAY CONTAIN RESTRICTED DATA
NOT SUBJECT TO AUTOMATIC
DECLASSIFICATION
Requires review by the Department of Energy
prior to public release" |
and directions for further action requested from the following contact in the Office of
Declassification, DOE: Document Declassification Division, (301) 903-4199.
- ADC
- Authorized Derivative Classifier
- AEA
- Atomic Energy Act
- AEC
- Atomic Energy Commission
- AIS
- Automated Information System
- AOSS
- Automated Office Support Systems
- CG-HR-1
- Historical Records Declassification Guide
- CG-RN-1
- DOE-DOD Classification Guide for the Naval Nuclear Propulsion Program
- COMSEC
- Communications Security
- DDE
- Declassification Date or Event
- DOD
- Department of Defense
- DOE
- Department of Energy
- DOS
- Department of State
- EMP
- Electromagnetic Pulse
- EMR
- Electromagnetic Radiation
- E.O.
- Executive Order
- ERDA
- Energy Research & Development Association
- FRD
- Formerly Restricted Data
- ID
- Inventory Differences
- IND
- Improvised Nuclear Device
- ISOO
- Information Security Oversight Office
- MFD
- Military First Destination
- NEST
- Nuclear Emergency Search Team
- NNPI
- Naval Nuclear Propulsion Information
- NNWS Nonnuclear Weapon State
- NSA
- National Security Agency
- NSI
- National Security Information
- NV
- Nevada Operations Office
- OMA
- Office of Military Application
- OPSEC
- Operations Security
- RD
- Restricted Data
- RDD
- Radiation Dispersal Device
- RF
- Radio Frequency
- RIS
- Reporting Identification Symbol
- RPM
- Revolutions Per Minute
- SANDS
- Surveillance Accident Nuclear Detection System
- SNM
- Special Nuclear Material
- SOP
- Standard Operating Procedures
- SSR
- Safe Secure Rail
- SST
- Safe Secure Trailers
- TSCM
- Technical Surveillance Countermeasures
- TSD
- Transportation Safeguards Division
- TSS
- Transportation Safeguards System
- U.K.
- United Kingdom
- XAD
- Exempt from Automatic Declassification