In February 1958, at Greenham Common airbase near Newbury, England, a U.S. Air Force B-47 experienced engine trouble on takeoff and jettisoned two full 1,700-gallon wingtip fuel tanks from an altitude of 8,000 feet. One or both of the falling tanks missed a designated safe impact area and exploded 65 feet behind a parked B-47 loaded with nuclear weapons.

The resulting fire burned for 16 hours, detonating the high explosives in at least one weapon, destroying the parked bomber, killing two people, and injuring eight others. It caused the release of radioactive material, including finely powdered uranium and plutonium oxides, at least 10 to 20 grams of which were found off base.

An adjacent hangar was also severely damaged, and other planes had to be hosed down to prevent their ignition by the intense heat of the nearby fire, which was fed by jet fuel and magnesium. The fire was allowed to burn itself out and was still smoldering several days later. (The population of the town of Newbury, the closest downwind village, later suffered a cluster of leukemia cases.)

The air force has never officially admitted that nuclear weapons were involved in this accident. The U.S. Air Force and the British Ministry of Defence had agreed in 1956—two years earlier—to deny that nuclear weapons were involved in any accident with an American nuclear bomber stationed in England. In 1985, the British government stated that the accident merely involved a parked B-47 that was struck by a taxiing B-47 on a training exercise, omitting any mention of the ensuing fire.

On January 16, 1961, an air force "quick reaction alert" F-100 based in England and loaded with a thermonuclear weapon intended for a Soviet target caught fire when, during engine run-up, the underwing fuel tanks were accidentally ejected and spilled fuel was ignited. The nuclear weapon mounted on the aircraft's centerline pylon was scorched and blistered before the flames were extinguished by the flight-line fire department.

Other U.S. allies in the North Atlantic Treaty Organization were put at risk by U.S. nuclear warheads stationed on their soil. On at least four occasions between mid-October 1961 and August 1962, Jupiter missiles carrying 1.4 megaton thermonuclear warheads were struck by lightning at their bases in Italy. In each incident, thermal batteries were activated, and in two cases, tritium-deuterium "boost" gas was injected into the warhead pits, partially arming them. After the fourth Jupiter incident, the air force erected protective lightning strike-diversion tower arrays at all of its Italian and Turkish missile launch sites.

On November 28, 1977, a U.S. Army CH-47 helicopter carrying nuclear weapons in West Germany crashed shortly after takeoff when it lost power in its no. 1 engine after the engine caught fire. The aircraft dropped rapidly, hit a row of trees, and came to rest in a planted field approximately 200 to 300 meters from the point of takeoff. The weapons were not seriously damaged, and were recovered from the aircraft wreckage.

These are just a few of the many accidents and incidents involving U.S. nuclear weapons based in foreign countries that were not mentioned in May 1981, when the Defense Department released what it claimed was the first "comprehensive" list of U.S. nuclear weapons accidents.

That compilation, titled "Narrative Summaries of Accidents Involving U.S. Nuclear Weapons, 1950-1980," listed only 32 "Broken Arrow"-type nuclear accidents and incidents during a 30-year period. Broken Arrows include lost weapons, burned weapons, dropped weapons, ruptured weapons, and weapons in which high explosives were inadvertently detonated; they are the most severe officially categorized nuclear weapon accidents. Less-severe accidents and incidents include "Bent Spears," "Dull Swords," and "Empty Quivers."

The 1981 list included accidents that fell into two categories: those that had been publicly disclosed when they occurred, and those in which radioactive fallout spread beyond the limits of a military base, either within the United States or in a foreign country. When radioactive contamination did not extend beyond a military base, the incident that caused the contamination was probably not publicly announced. Of the incidents listed in the 1981 paper, at least seven were not made public when they happened and several had not been previously disclosed. In only 14 cases had Defense revealed at the time of the incident that nuclear weapons were involved.

At least a few government officials were better informed: As reported by Shaun Gregory in his 1990 book The Hidden Cost of Deterrence: Nuclear Weapons Accidents, President John F. Kennedy was briefed in 1961 on more than 60 U.S. nuclear weapons accidents that had occurred since the end of World War II, including two instances in which "nuclear-tipped anti-aircraft missiles" were inadvertently launched.

By January 1968, Defense had publicly announced only 13 major aircraft accidents between 1958 and 1968 that involved nuclear weapons. The May 1981 accident list expanded that total to 32, including 27 aircraft accidents, one loss of a submarine, three missile incidents, and one explosion at a storage facility.

Still, the 1981 list, an apparently ad hoc compilation, just barely scratched the surface. Other privately generated and official government reports put the U.S. nuclear weapons accident/incident total well above 32. A 1989 Greenpeace publication lists a total of 383 nuclear weapons involved in navy incidents between 1965 and 1977, and a 1985 General Accounting Office study noted that the navy had reported 233 incidents involving nuclear weapons between 1965 and 1983.

A 1973 Sandia Laboratories report, citing a then-classified army compilation, stated that between 1950 and 1968, a total of 1,250 U.S. nuclear weapons were involved in accidents or incidents of varying severity, including 272 (22 percent) in circumstances involving impacts which, in several instances, caused the detonation of the weapon's conventional high explosives. (All percentages are rounded to the nearest whole number.)

Of these 272 weapons, 107 bombs or rockets were unintentionally dropped during storage, assembly, or loading (39 percent); 48 warheads mated to missiles or re-entry vehicles were involved in handling drops and accidents on pads or in silos (18 percent); 41 bombs or warheads were aboard aircraft that crashed (15 percent); 26 warheads in containers were in accidents that occurred during storage, assembly, or loading (10 percent); 24 weapons were jettisoned or inadvertently released from aircraft or ships (9 percent); 22 weapons and warhead assemblies were involved in ground transportation crashes (8 percent); and four weapons were accidentally crushed or punctured (1.5 percent). Despite these revelations, Defense has yet to update or re-issue its 1981 paper in a more complete or exhaustive form.

Some Cold War weapons-handling practices were particularly accident prone. At least one procedure, a missile warhead "recycle" or "yo-yo," involved the temporary removal of a missile re-entry vehicle to allow servicing of parts in both the warhead and the missile; the two could not be serviced while they were mated. This was a more complicated and inherently more risky procedure than a simple bomb upload or download. It is probable that at least a few of the 48 missile-warhead handling accidents cited in the 1973 Sandia study occurred during "yo-yo" procedures.

Since 1988, I have assembled details of 96 U.S. nuclear weapons accidents and incidents, ranging in severity from gouges in external casings to fires and high explosive detonations. While most information about accidents and incidents other than the 32 officially disclosed cases has come from recently declassified congressional documents, there are other sources—a handful of books about U.S. nuclear weapons accidents and a February 1991 Environmental Protection Agency study which listed radioactively contaminated sites, including some sites where air force bombers had crashed.

Why Defense has yet to acknowledge incidents beyond the 32 disclosed in 1981 is a mystery. As long as nuclear weapons are in the custody of the armed services, handling accidents seem inevitable, although the likelihood of the most violent incidents of the past has been reduced. Nuclear-armed bombers no longer fly over land, nuclear weapons have been removed from army custody, and in March 1991 the navy began mating warheads to ballistic missiles only after they are loaded aboard submarines. Nonetheless, the possibility of future accidents cannot be completely ruled out as long as air force warheads are routinely removed for servicing and inspection.

Continued and unnecessary secrecy about past accidents only increases suspicion, both within and outside the United States, that other serious accidents have occurred and that there has been undisclosed radiological contamination in one or more of the other countries that hosted U.S. nuclear forces during the Cold War. (For example, there have been widespread allegations in Britain that U.S. bombers involved in crashes and ground fires spread fallout beyond the boundaries of military reservations.)

Until the Defense Department comes clean about past nuclear weapons accidents, a cloud of doubt and uncertainty will continue to hover over U.S. foreign relations.

Click here to get your subscription to The Tybee News