Declassification of Certain Characteristics of the United States NuclearWeapon Stockpile

U.S. Department of Energy, Office of the Press Secretary, Washington, DC20585

Declassification of Certain Characteristics of the United States NuclearWeapon Stockpile

Table of Contents

Who Are the Key Stakeholders?
Questions and Answers

The Department of Energy and the Department of Defense have jointlydeclassified certain characteristics of the Nation's nuclear weaponstockpile.


  • The Department of Energy and the Department of Defense havejointly declassified the total megatonnage of the nuclear weaponstockpile for the years 1945 to the present.
  • The Department of Energy and the Department of Defense havejointly declassified the total number of nuclear weapons in thestockpile for the years 1949 to 1961.
  • The Department of Energy and the Department of Defense havejointly declassified the total number of weapon builds by year forweapon systems fully retired.
  • The Department of Energy and the Department of Defensehave jointly declassified the total number of weapon retirements for theyears 1945 to 1989. Disassembly of weapons for disposal from 1980 tothe present is also provided.
  • See attached charts for detailed descriptions of thedeclassified stockpile characteristics.


  • The size of the stockpile has changed dramatically over the past50 years. In recent years, a large number of weapons have been retiredin response to treaty obligations and unilateral commitments.
  • After reaching peak megatonnage around 1960, total megatonnage inthe stockpile has decreased to about 10 percent of the peak.
  • The quantities listed here are based on the evaluation of therecords available. The quantities may be updated or revised in thefuture after re-evaluation of the methodology used originally.
  • Retirement numbers provided here reflect weapons retired forconversions, modifications, or disassembles for disposal. Retirementnumbers depend critically on how the term "retirement" is defined.
  • Disassembly for disposal reflect weapons actually dismantledwithout including the number of weapons dismantled to change out acomponent within the weapon or dismantled and rebuilt for qualityassurance reliability testing.


  • As part of the Secretary of Energy's Openness Initiative, theDepartment of Energy and the Department of Defense are declassifyinginformation regarding characteristics of the United States nuclearweapon stockpile. As a result of this declassification, the Americanpublic will have information that is important to the current debateover the nuclear arsenal. The information released will help provide ahistorical perspective of how the stockpile has changed over the past 50years. It should encourage other nations to declassify similar nuclearweapon stockpile information.
  • With the U.S. release of this information, it is hoped that othernuclear weapon states will be encouraged to release similar information.The release of retirement rates up to 1989 will show nonnuclear weaponstates that the United States has acted responsibly by retiring anddismantling weapons it no longer requires.

Who Are the Key Stakeholders?

  • The Public. The public will have a better understanding of thenature of the Nation's nuclear deterrent.
  • Freedom of Information Act Requesters. This information has beenlong sought by certain public interest groups through Freedom ofInformation Act requests.
  • Public Interest Organizations. Stakeholders includeenvironmental, safety and health groups, historians, archivists,researchers, scientists, and industrial workers, as well as State andFederal personnel. With this declassification, those interested inoversight of nuclear weapons related activities will have additionalinformation regarding the U.S. nuclear weapon stockpile. Publicinterest organizations which have expressed such an interest include(but are not limited to): Energy Research Foundation, EnvironmentalInformation Network, Friends of the Earth, Greenpeace, League of WomenVoters, Livermore Conversion Project, Military Production Network,National Security Archive, Natural Resources Defense Council, NevadaDesert Experience, Physicians for Social Responsibility, PlutoniumChallenge, and the Sierra Club.
  • Arms Control Negotiators. Negotiators for the UnitedStates can use this information to seek similar information from other nuclearweapon states.


U.S. Department of Energy
Office of Public Affairs
Contact: Sam Grizzle
(202) 586-5806


Total Megatonnage of the U.S. Nuclear Weapon Stockpile

Total United States Nuclear Stockpile 1945 to 1961

Builds of United States Nuclear Weapons Now Retired

Total Weapon Retirements by Year

Total Number of Nuclear Weapons Dismantled

Declassified Stockpile Data 1945 to 1994

U.S. Department of Energy, Office of the Press Secretary, Washington, DC20585


Q. Why wasn't this information declassified earlier?

A. The United States maintains the nuclear weapon stockpile as adeterrent. During the Cold War, most information concerning thestockpile was classified for clear reasons of national security. Uponreview, it was determined that some general information concerning thestockpile can now be released without harm to national security.

Q. When will more detailed information on the nuclear stockpile bedeclassified?

A. The nuclear stockpile is extremely important to the defense of theNation. At this time, release of more detailed information is notjudged to be in the Nation's best interest.

Q. Why are total quantities provided only up to 1961?

A. Past total stockpile numbers which are composed, even partially, ofweapon systems still in the stockpile remain classified. Further dataon total stockpile numbers may be released in the future as additionalweapon systems are retired.

Q. Why are retirement rates and disassembly for disposal ratesdifferent from each other from year to year?

A. Retirement is an accounting change that authorizes removal of aweapon from the nuclear stockpile and its transfer to the Department ofEnergy for conversions, modifications, or eventual disassembly. Disassembly for disposal is the process of taking apart a nuclearweapon. Disassembly rates depend on available capacity at Pantex.

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