The Manhattan Project Resources

U.S. Department of Energy

HSS Office of Classification

Office of History and Heritage Resources

Drawing Back the Curtain of Secrecy, Contents and Foreword

Drawing Back the Curtain of Secrecy

Restricted Data Declassification Policy, 1946 to the Present
RDD-1

June 1, 1994
U.S. Department of Energy, Office of Declassification


Table of Contents

FOREWORD
I. SCIENCE AND TECHNOLOGY
A. GENERAL
B. MATHEMATICS
C. CHEMISTRY
D. THEORETICAL AND EXPERIMENTAL PHYSICS
E. METALLURGY
F. INSTRUMENTS AND EQUIPMENT
II. MATERIALS
A. DEUTERIUM INCLUDING HEAVY WATER
B. TRITIUM
C. BERYLLIUM
D. POLONIUM
E. THORIUM
F. PROTACTINIUM
G. URANIUM
H. NEPTUNIUM
I. Np 237
J. Np 239
K. UF6
L. BORON 10
M. PLUTONIUM
N. UCl4
O. ELEMENTS 95 AND ABOVE
P. FISSION PRODUCTS
Q. LITHIUM AND ITS COMPOUNDS
R. MISCELLANEOUS MATERIALS INFORMATION
III. ISOTOPE SEPARATION
A. ELECTROMAGNETIC PROCESS (Y-12)
B. DIFFUSION PROCESSES
C. CENTRIFUGE
D. GASEOUS DIFFUSION
E. LASER ISOTOPE SEPARATION (LIS)
F. MISCELLANEOUS ISOTOPE SEPARATION INFORMATION
IV. REACTORS
A. SMALL EXPERIMENTAL PILES
B. ENRICHED REACTORS
C. EXPERIMENTAL BREEDER REACTORS
D. EFFECTS OF RADIATION IN REACTOR DESIGN
E. LIQUID METAL COOLANTS
F. ARMY NUCLEAR POWER PACKAGE PROGRAM
G. CONTROLLED THERMONUCLEAR PROGRAM - PROJECT SHERWOOD
H. OTHER CIVILIAN NUCLEAR POWER
I. PRODUCTION REACTORS
J. MISCELLANEOUS REACTOR TOPICS
V. NUCLEAR WEAPONS AND RELATED TECHNOLOGY
A. THEORY
B. MILITARY UTILIZATION
1. Delivery and use of an atomic weapon
2. Testing
3. Atomic Event Data
4. Future Atomic Tests
5. Miscellaneous Test Information
6. Phenomenology
7. Damage
8. Significance and comparisons
9. Radiological warfare - General.
10. Radiological warfare - Offensive.
C. FISSION WEAPONS
D. THERMONUCLEAR WEAPONS
E. NUCLEAR DIRECTED ENERGY SYSTEMS
F. STOCKPILE
G. ENHANCED RADIATION WEAPONS
H. MINIMUM RESIDUAL RADIATION (MRR) WEAPONS
VI. HEALTH, SAFETY AND ENVIRONMENT
VII. NAVAL NUCLEAR PROPULSION INFORMATION
A. PROJECT NEPS (Nuclear Energy Propulsion for Submarines)
VIII. INERTIAL CONFINEMENT FUSION
IX. MISCELLANEOUS
A. ROCKET AND AIRCRAFT NUCLEAR PROPULSION (ANP) PROGRAM
B. THE PLOWSHARE PROGRAM
APPENDIX A
TABLE A -- LIST OF CLASSIFIED SUBSTANCES
TABLE B -- NUCLEAR PROPERTIES
APPENDIX B
PARAGRAPH 5 OF THE 1956 JOINT AEC/DOD CLASSIFICATION GUIDE
NOTES

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FOREWORD

New Horizons

The breakup of the Soviet Union, the end of the Cold War, and other national and international events of recent history have enabled our national leadership to reconsider the constraints placed on both classified and unclassified Government information. The Secretary of Energy, Ms. Hazel R. O'Leary, has demonstrated a commitment to her Openness Initiative through her frequent public meetings with customers and stakeholders interested in the many functions of the Department. In addition, she has directed that a comprehensive concerted effort to declassify and release information be undertaken. To implement this effort, a search of the Department's files for all previous declassification actions has been made. A result of this search is this document which provides a compilation of information regarding the topics which have been declassified over the years. Although these topics were declassified, they have never before been presented in this comprehensive form. This is a compendium of the declassification actions taken from 1946, following the Manhattan Project for the development of atomic weapons, to the present day.

This document provides historical perspective on the sequence of declassification actions performed by the Department of Energy and its predecessor agencies. It is meant to convey the amount and types of information declassified over the years. Although the language of the original declassification authorities are cited verbatim as much as possible to preserve the historical intent of the declassifications, this document does not provide the reader sufficient basis or authority to decide whether other documents are classified or not. These decisions are made by specially trained professional staff who use classification guides designed for that specific purpose. Nevertheless, it is hoped that this document will help educate the public on the technical policy decisions that underlie the Department's formidable classification responsibility. Public input is welcome regarding improvements the Department may consider to address legitimate needs for declassifying information when appropriate, yet maintain control of information in the interest of national security.

How We Got Here

The first atomic detonation, test shot Trinity, on July 16, 1945, near Alamagordo, New Mexico, was a device developed and produced under the Manhattan Project. This was followed at Hiroshima, Japan, on August 6, 1945, and Nagasaki, Japan, on August 9, 1945; detonations which heralded the end of World War II. Immediately following World War II there was considerable pressure from the academic and industrial sectors of the country to declassify and release information developed during the Manhattan Project. It is well to remember that at this point in time there was no Atomic Energy Act, no Atomic Energy Commission, and no Restricted Data category of information.

In November 1945, General L. R. Groves, head of the Manhattan Project, asked Dr. R. C. Tolman to develop a declassification policy for the classified information which had been developed. Dr. Tolman, who was the Dean of the Graduate School at the California Institute of Technology and had served as a science advisor to General Groves during the war, selected a distinguished group to help him in this task. The Tolman Committee developed declassification guidance that was accepted by General Groves and published in March 1946 as a Declassification Guide for Responsible Reviewers. The declassification guidance for the year 1946 is based on the work of the Tolman Committee. The outline of topics used in the 1946 declassification guidance was used as the basic outline for the topics in this compendium. Modifications have been made to accommodate the additional categories of information which have been declassified since that time.

The Atomic Energy Act, approved on August 1, 1946, established the Atomic Energy Commission (AEC) and provided the historical and legal basis for its successor agencies: the Energy Research and Development Administration (ERDA) (January 20, 1975, through September 30, 1977) and the current Department of Energy. Among other things, it recognized the need for the close relationship between the AEC and the Department of Defense (DOD) which has facilitated the approval of joint AEC/DOD guides containing classification and declassification actions for almost a half century. The Act also recognized the need to emphasize that atomic energy information is of a special and unique type, identified it as Restricted Data, and defined it as all data concerning the manufacture or utilization of atomic weapons, the production of fissionable material, or the use of fissionable material in the production of power.

It is important to note that this Act is the basis for classification of atomic energy information and that all information falling under the definition of Restricted Data is classified from its inception. By this Act, Congress has decreed that Restricted Data is different; it is "born classified," and it remains classified until a positive action is taken to declassify it. This is directly opposite to information classified under the provisions of the various Executive orders dealing with National Security Information (NSI). NSI is not automatically classified, and it becomes classified only when it meets the criteria defined in the current Executive order and a decision to classify the information is made by an original classification authority.

The first International Declassification Conference was held in Washington, D.C., November 14, 15, and 16, 1947, among representatives of the United States, the United Kingdom, and Canada to discuss revisions to the Declassification Guide for Responsible Reviewers. As a result of that meeting a revised guide was adopted and published as the Declassification Guide for General Application, dated March 15, 1948.

A Weapon Effects Classification Board was established in August 1948 to determine the proper classification of nuclear weapon effects. The Board met on August 13, 1948, at Los Alamos under the chairmanship of Dr. N.E. Bradbury and recommended classification guidance for the weapon effects area. Certain items of information included in the recommended guidance were declassified and designated as unclassified in the guidance.

The 1946 Atomic Energy Act was amended and enacted as the Atomic Energy Act of 1954, which we operate under today. Among other things, the new Act modifies the definition of Restricted Data to include "design" of atomic weapons and changes the words "fissionable material" to "special nuclear material." It also provides for the declassification of Restricted Data following a determination that such information can be published without undue or unreasonable risk to the common defense and security. In addition, this 1954 Act provided for the transclassification of information related primarily to the military utilization of atomic weapons and also to the atomic energy programs of other nations. Transclassification moves information from Restricted Data to Formerly Restricted Data and causes it to be protected as National Security Information.

Information Versus Documents

In the discussion of classified matters, it is important to note the distinction between "information" and "documents." Information is regarded as facts, data, or knowledge, whereas documents or material are the means through which information is conveyed. When an item of Restricted Data is declassified, that bit of declassified information becomes eligible for public release regardless of the nature of the documents of which it may be a part. A classified document will always contain some classified information, will normally contain some unclassified information, and may contain declassified information. Such a document cannot be released until all of the classified information is deleted. The declassification of an item of information may result in the release of an entire undeleted document; then again, the declassification may have little effect due to the continued classified nature of the remaining document content.

Public Release

The philosophy of declassification and release of information changes with the passage of time. In view of national objectives in the 1940's, literally everything concerning atomic energy programs was classified. Immediately after World War II, an effort was made to remove many the constraints on information concerning nuclear chemistry, metallurgy, physics, etc. This was followed by declassification of certain information regarding nuclear weapons tests, reactors, materials production, and even some weapon design and utilization data. However, declassification of information did not necessarily equate to its public release. As scientists ascertained that certain information had been declassified, they published reports, attended meetings, and, indeed, spread the word about their specific area of interest. But, for the greatest part, the fact that information was declassified went only to classification officers whose duties required it; seldom did such action reach the attention of the public in general.

Customers Use

The publication of this compendium is intended to provide information about which the public may have been generally unaware. It is felt that many people do not know that there have been declassification actions since the beginning of the atomic age, especially since most of these actions were considered to be of little interest to the public as a whole and, therefore, were not publicly announced. The document at hand provides a description of the declassification actions that were taken.

In addition to enhancing the knowledge of the general public, this document should be of interest and utility to historical researchers and individuals interested in the security of information. Perhaps it contains bits of information which may add to the larger picture or even solve certain problems encountered. Its value in this area can only be assessed at a point in the future.

Things as They Really Are

This document is the result of a search reaching back for almost half a century. During that time, the records were maintained under three Government agencies with differing goals and philosophies. The files were also affected by several internal reorganizations, relocations, amendments to document retention regulations, and complete personnel changes at all levels. However, with the able assistance of those responsible for records maintenance, the voluminous data contained in this document was recovered from the files.

The declassification actions were gleaned from many and varied source documents. They included staff papers, minutes of meetings, action memorandums, correspondence, classification and declassification guides, weapons bulletins, and isotope separation bulletins. While the declassification actions themselves are not classified, most of the source documents remain classified due to the remainder of their content. Topics in this compilation are quotes from the original source documents to the extent possible. Where an exact quote is not possible, the editorial adjustments made for clarity have been kept to a minimum consistent with maintaining the intent of the declassification action. Some topics may appear terse, non-explanatory, incomplete or inconsistent, but they are copied as exactly as possible from their source document.

Each topic is followed by a reference number indicating the year of the declassification and its place in the chronological order of declassification actions for that year. For example, 49-2 is the second declassification action in 1949. Some declassification actions contain only a single topic, while most are actions with multiple topics. Particular topics may deal with more than one subject within this compendium; therefore, these items appear more than once and are cross- referenced to one another. In addition, many topics list exceptions to the declassification action. The exceptions identify information which remained classified as of the date of the declassification action. These exceptions are printed in italics in this compendium.

As time has passed, many declassified topics were superseded by more recent declassifications. Early day exceptions often no longer apply; they have been overtaken by other events. For example, in 1955 the only information concerning the Controlled Thermonuclear Reactor that was declassified was the fact of interest in such a program and the sites where work was underway. In 1959, all information regarding this program was declassified. There are many such examples, but, in the interest of completeness, this compendium incorporates all of the declassifications discovered.

Users of this compilation should note that it is possible that there are other declassification actions which have not been discovered as yet in the search of the files which was undertaken for this effort. As additional topics are declassified or previously undiscovered declassification actions are found, this compendium will be amended, updated, and publicly released.


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