MILNET: Nuclear Weapon Accidents

Portions based upon U.S. Department of Defense and Department of Energy material reported on in an analysis from the Center For Defense Information magazine, The DEFENSE MONITOR in 1991. The original source document is U.S. Nuclear Weapons Accidents: Danger In Our Midst 1 which analyzes the U.S. DoD report titled U.S. Department of Defense Nuclear Weapons Accidents 1950-1980.

In 1981, the DoD and DoE (and more recently the DoE's Transportation Safeguards Division reported publicly on the incidents involving nuclear weapons.

In this specific report, the DoD comments on some 32 incidents dealing with weapons, material and components in the thirty year period from 1950 through 1980. CDI adds comments based upon other information and adds their particular flavor of interesting information such as the effects of a nuclear explosion of the nuclear weapons involved or a brief on the aircraft involved. MILNET notes that the DoD reports states that none of the weapons involved were ever in the armed stage, the nuclear "pits" outside the weapons. However, contamination from nuclear material in the bomb casings certainly caused low level radioactive contamination is probable in all cases where bombs burned or broke apart, and high level radiation contamination could have occurred where a nuclear capsule (the pit) were on board an aircraft which impacted or exploded in the air.

To our knowlege, no armed bomb has been involved in an accident. It is not clear whether ICBM warheads involved in incidents have ever used the physically separated method for nuclear safety. Therefore a silo incident could possibly be far more risky. Today, siloed missles are not on "targeted alert" and only a small number of siloed missiles are in operation (primarily at one ICBM launch site in the U.S). There are active ICBMs found on Ballistic Missile Submarines, however we have not seen accident data on this inventory.

At MILNET we have a number of eyewitness reports on so called "non-dangerous" incidents that have not been reported by the DoD, those which might be classified as "Dull Sword" incidents (see below).

The Defense Monitor article also includes their own statements about other incidents not found in the DoD report, however in a number of cases the article does not cite the source.

The DoD report also goes to some length to state that nuclear weapons are not armed unless in true wartime conditions, and that accidents which have occurred never posed a risk of nuclear explosion. CDI on the other hand uses fairly inflammatory language to imply that the DoD/DoE statement is false and misleading, citing Daniel Ellsberg's discoveryi of documents that quote physicist Ralph E. Lapp as indicating the weapon in a January 1961 accident accident was only one safety switch away from (implied nuclear) detonation.

The Defense Monitor analysis leads of with a summary (which we further summarize):

• A total of 32 serious nuclear weapons accidents documented in the report
• Reports tend to be disquieting as well as incomplete or vague
• Weapons are located in hundreds of locations both domestically and abroad
• Not all significant accidents are reported under the current (1981) DoD reporting system.
• As the numbers of weapons increase, so do the risks of accidents.

As stated, the DoD report makes a number points we believe are important for the public to know:

• There has never been even a partial [known as a "fizzle" - MILNET] inadvertant U.S. nuclear detonation despite severe stresses imposed upon the weapons in the accident reports.
• Nuclear weapons are never carried on training flights
• Airborne Alert created the greatest risk since the bomb casings were carried on these flights, and comprised the bulk of the significant accidents. Airborne Alert ceased in 1968 and Ground Based Alert ceased in 1995.
• Many of the locations of nuclear weapons accidents are politically sensitive and therefore remain classified except in two cases.
• All locations of actual weapons location remains classified by U.S. policy.
• Most of the weapons carriers specified in the report are no longer in the U.S. inventory [Strategic Air Command bombers - MILNET].

It is also instructive to look at the U.S. DoD definitions for nuclear accidents (also contained in the article):

An "accident involving nuclear weapons" is defined as

An unexpected event involving nuclear weapons or nuclear weapons components that results in any of the following: Accidental or unauthorized launching, firing, or use, by U.S. forces or supported allied forces, of a nuclear-capable weapon system which could create the risk of an outbreak of war. Nuclear detonation. Non-nuclear detonation or burning of a nuclear weapon or radioactive weapon component, including fully assembled nuclear weapon, an unassembled nuclear weapon, or a radioactive nuclear weapon component. Radioactive contamination Seizure, theft, or loss of a nuclear weapon component, including jettisoning. Public hazard, actual or implied

Also, the article documents the U.S. Navy defintions and code words for various types of mishaps with nuclear accidents:

NUCFLASH	Any accidental or unauthorized incident involving a possible detonation of a nuclear weapon by U.S. Forces which could create the risk of nuclear war between the U.S. and the USSR.
BROKEN ARROW	The accidental or unauthorized detonation, or possible detonation of a nuclear weapon (other than war risk); Non-nuclear detonation or burning of a nuclear weapon; Radioactive contamination Seizure, theft, or loss of a nuclear weapon or component (including jettisoning); Public hazard, actual or implied.
BENT SPEAR	Any nuclear weapons significant incidents other than nuclear weapons accidents or war risk detonations, actual or possible.
DULL SWORD	Any nuclear weapon incident other than significant incidents.
FADED GIANT	Any nuclear reactor or radiological accidents involving equipment used in connection with naval nuclear reactors or other naval nuclear energy devices while such equipment is under the custody of the Navy.
	U.S. Department of the Navy, Chief of Naval Operations, 15 July 1978

Below we summarize the events documented in the article, with links to the specific event description in the reprint of the article for further reading:

1. 2/13/50 - AF B-36, off British Columbia
2. 4/11/50 - AF B-29, Manzano Base, Albuquerque, New Mexico, U.S
3. 7/13/50 - AF B-50, Lebanon, Ohio, U.S.
4. 8/5/50 - AF B-29, Fairfield-Sussun Air Force Base, California, U.S. (now TRAVIS AFB)
5. 11/10/50 - AF B-50, over water outside U.S.
6. 3/10/56 - AF B-47, Mediterranean Sea
7. 7/27/56 - AF B-47, Lakenheath Royal Air Force Station near Cambridge, England
8. 5/22/57 - AF B-36, Kirtland AFB, New Mexico, U.S.
9. 7/28/57 - AF C-124 cargo plane, Off U.S. East Coast
10. 10/11/57 - AF B-47, Homestead AFB, Florida, U.S.
11. 1/31/58 - AF B-47, Sidi Slimane, French Morocco
12. 2/5/58 - AF B-47, Savannah River, Georgia, U.S.
13. 3/11/58 - AF B-47, Florence, South Carolina, U.S.
14. 11/4/58 - AF B-47, Dyess AFB, Abilene, Texas, U.S.
15. 11/26/58 - AF B-47, Chennault AFB, Lake Charles, Louisiana, U.S.
16. 1/18/59 - AF F-100 fighter, Pacific Base (could have been Okinawa, Phillipines, Taiwan, South Korea, or Thailand)
17. 7/6/59 - AF C-124 cargo plane, Barksdale AFB, Bossier City, Louisiana, U.S.
18. 9/25/59 - USN P-5M, Off Whidbey Island, Washington, U.S.
19. 10/15/59 - AF B-52, Hardinsberg, Kentucky, U.S.
20. 6/7/60 - BOMARC AGM, McGuire AFB, near Trenton, New Jersey, U.S.
21. 1/24/61 - AF B-52, Goldsboro, North Carolina, U.S.
22. 3/14/61 - AF B-52, Yuba City, California, U.S.
23. 11/13/63 - Storage, Medina Base, San Antonio, Texas, U.S.
24. 1/13/64 - AF B-52, Cumberland, Maryland, U.S.
25. 12/5/64 - AF LGM 30B (Minutemand I ICBM), Ellsworth Air Force Base, Rapid City Dakota, U.S.
26. 12/8/64 - AF B-58, Bunker Hill (Now Grissom) AFB, Peru, Indiana, U.S.
27. 10/11/65 - AF C-124 cargo, Wright-Patterson AFB, near Dayton, Ohio, U.S.
28. 12/5/65 - USN A-4, at sea over the Pacific Ocean more than 500 miles from land
29. 1/17/59 - AF B-52, Palomares, Spain
30. 1/21/68 - AF B-52, Thule Air Base, Greenland
31. Spring 1968 - Classified, Atlantic Sea (CDI guess - U.S.S. Scorpion, Off the Azores
32. 9/19/80 - AF Titan II ICBM, Damascus, Arkansas, U.S.
    
    

• 3/18/1963 - AF Titan I ICBM,  ICBM, near Moses Lake, Washington, U.S.
• 1/20/1966 - USN Terrier Guided Missile,  NAS Mayport, Florida, U.S.

CDI also reports on other events as well:

• 1/4/58 - AEC material on train, Hamburg, New York, U.S.
• 11/4/61 - AEC material in trailer, Winslow, Arizona, U.S.
• 12/3/62 - Weapons components on train, Marietta, Georgia, U.S.
• 12/80 - Nuclear material on trailer, Fort Collins, Colorado, U.S.
• 8/9/65 - Titan II, Searcy, Arkansas, U.S.
• 8/24/78 - Titan II, Rock, Kansas, U.S.

CDI also cites some ten other silo incidents from March 1979 to September 1980 that were not covered in the DoD report as well as some 125 total incidents at Arkansas and Texas sites between 1975 and 1979.

MILNET has an eyewitness account of three relatively harmless events that would not have been reported in the DoD report, indicating the level of incident the DoD deems is not sufficiently dangerous enough to report on.

A more recent report of a nuclear incident we found interesting occurred with a nuclear tipped AGM-129 cruise missile reported in October of 2007 (incident occurred on August 29, 2007).  According to several sources including the Washington Post, a flight of six AGM-129s were involved in a "bent spear" incident when U.S. airmen uploaded 12 AGM-129s onto a B-52 bombers wing hardpoints for transport.  They were supposed to have uploaded 12 unarmed nukes...unfortunately, six on the left wing were all fully loaded with nuclear warheads...ooops.  The weapons were left without special guard for 36 hours at two different bases at the ultimate cause was the initial screwup of storing the nuclear warhead armed versions in along with the unarmed.