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

"Drawing Back the Curtain of Secrecy"

Restricted Data Declassification Decisions, 1946 to the Present

(RDD-3)

January 1, 1996

U.S. Department of Energy
Office of Declassification

NOTICE
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 declassification, THIS DOCUMENT IS NOT TO BE USED AS THE BASIS FOR DECLASSIFYING DOCUMENTS AND MATERIALS without specific authorization from the Office of Declassification. Classification guides designed for that specific purpose must be used.

Approved for Public Release


Table of Contents

FOREWORD
OVERVIEW
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
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
VIII. INERTIAL CONFINEMENT FUSION
IX. MISCELLANEOUS
A. ROCKET AND AIRCRAFT NUCLEAR PROPULSION (ANP) PROGRAM (includes NEPA)
B. THE PLOWSHARE PROGRAM
APPENDIX A, Tables A and B of the 1948 Declassification Guide for General Application
APPENDIX B, Appendix A to the 1950 Declassification Guide for General Application and the 1950 Declassification Guide for Responsible Reviewers
APPENDIX C, Paragraph 5 of the 1956 Joint AEC/DOD Classification Guide
APPENDIX D, Nuclear Weapons Stockpile Data Table
APPENDIX E, Residual Radiation Contours
Footnotes

February 6, 1996, Press Conference Documents