Restricted Data (RD) is a category ofclassified information in the United States that is defined by theAtomic Energy Act of 1954 as:
all data concerning (1) design, manufacture, or utilization ofatomic weapons; (2) the production ofspecial nuclear material; or (3) the use of special nuclear material in the production of energy, but shall not include data declassified or removed from the Restricted Data category pursuant to section 142 [of the Act].[1]
The fact that its legal definition includes "all data" except that already specifically declassified has been interpreted to mean that atomic energy information in the United States isborn classified, even if it was not created by any agency of the U.S. government.[2] The authority of theUnited States Department of Energy (DOE) to implement this authority as a form ofprior restraint was only once tested in court, with inconclusive results.[3][4]
"Restricted Data" should not be confused with the classification category of "Restricted", a relatively low category of classification. "Restricted Data" is not a level of classification; rather, a document can be classified asConfidential,Secret, orTop Secret, while also containing "Restricted Data." In addition, a document containing Restricted Data could also containCritical Nuclear Weapon Design Information (CNWDI). In this way, a document, for instance, could be classified as "Secret" (S), "Secret//Restricted Data" (S//RD), or "Secret//Restricted Data-Critical Nuclear Weapon Design Information" (S//RD-CNWDI) depending on the type of information a document contains.
Access to Restricted Data requires anL clearance or aQ clearance from the Department of Energy.
The concept was initially introduced, with similar wording, in theAtomic Energy Act of 1946. It was added at a relatively late moment to the bill by its creators, after theGouzenko affair was leaked to the press and caused a fear of loss of "the secret" of the atomic bomb, as well as fears that theEspionage Act of 1917 was not sufficiently adequate.[5]
The Atomic Energy Act of 1946 further specified that anyone who:
- communicates, transmits, or discloses... any document, writing, sketch, photograph, plan, model, instrument, appliance, note, or information involving or incorporating restricted data... to any individual or person, or attempts or conspires to any of the foregoing, with intent to injure the United States or with intent to secure an advantage to any foreign nation, upon conviction thereof, shall be punished bydeath orimprisonment for life... or, by a fine of not more than $20,000 or imprisonment for not more than twenty years, or both...[1]
The act empowered and required the then-newly-createdAtomic Energy Commission to regulate Restricted Data both internally and externally.
Section 142 of the Atomic Energy Act (42 U.S.C. 2162) allows certain nuclear weapons information to be removed from the Restricted Data category to be handled by theDepartment of Defense or theIntelligence Community.[6]
Critical Nuclear Weapon Design Information (CNWDI) is a category of RD provided to the DoD that reveals the theory of operation or design of components of a thermonuclear or implosion-type fission bomb, warhead, demolition munition, or test device. It is classified as either Secret (S//RD) or Top Secret (TS//RD).[6]
TheSigma categories are subject areas of RD nuclear weapons data related to nuclear weapons, components, or explosive devices or materials that have been determined to require additional protection. The current Sigma categories are Sigma 14, Sigma 15, Sigma 16 and Sigma 20.[7]
