List of Military Nuclear Accidents - 1960s

1960s

• June 7, 1960 – New Egypt, New Jersey, USA – Nuclear warhead damaged by fire
  • A helium tank exploded and ruptured the fuel tanks of a USAF BOMARC-A surface-to-air missile at McGuire Air Force Base, New Jersey. The fire destroyed the missile, and contaminated the area directly below and adjacent to the missile.
• October 13, 1960 – Barents Sea, Arctic Ocean – Release of nuclear materials
  • A leak developed in the steam generators and in a pipe leading to the compensator reception on the ill-fated K-8 while the Soviet Northern Fleet November-class submarine was on exercise. While the crew rigged an improvised cooling system, radioactive gases leaked into the vessel and three of the crew suffered visible radiation injuries according to radiological experts in Moscow. Some crew members had been exposed to doses of up to 1.8–2 Sv (180–200 rem).

• January 3, 1961 – National Reactor Testing Station, Idaho, USA – Accidental criticality, steam explosion, 3 fatalities, release of fission products
  • During a maintenance shutdown, the SL-1 experimental nuclear reactor underwent a prompt critical reaction causing core materials to explosively vaporize. Water hammer estimated at 10,000 pounds per square inch (69,000 kPa) struck the top of the reactor vessel propelling the entire reactor vessel upwards over 9 feet (2.7 m) in the air. One operator who had been standing on top of the vessel was killed when a shield plug impaled him and lodged in the ceiling. Two other military personnel were also killed from the trauma of the explosion, one of which had removed the central control rod too far. The plant had to be dismantled and the contamination was buried permanently nearby. Most of the release of radioactive materials was concentrated within the reactor building.

For more details on this topic, see SL-1.

• January 24, 1961 – Goldsboro B-52 crash – Physical destruction of a nuclear bomb, loss of nuclear materials
  • A USAF B-52 bomber caught fire and exploded in midair due to a major leak in a wing fuel cell 12 miles (19 km) north of Seymour Johnson Air Force Base, North Carolina. Five crewmen parachuted to safety, but three died—two in the aircraft and one on landing. The incident released the bomber's two Mark 39 hydrogen bombs. Three of the four arming devices on one of the bombs activated, causing it to carry out many of the steps needed to arm itself, such as the charging of the firing capacitors and, critically, the deployment of a 100-foot (30 m) diameter retardation parachute. The parachute allowed the bomb to hit the ground with little damage. The fourth arming device — the pilot's safe/arm switch — was not activated preventing detonation. The second bomb plunged into a muddy field at around 700 mph (300 m/s) and disintegrated. Its tail was discovered about 20 feet (6 m) down and much of the bomb recovered, including the tritium bottle and the plutonium. However, excavation was abandoned due to uncontrollable ground water flooding. Most of the thermonuclear stage, containing uranium, was left in situ. It is estimated to lie around 55 feet (17 m) below ground. The Air Force purchased the land and fenced it off to prevent its disturbance, and it is tested regularly for contamination, although none has so far been found.

• March 14, 1961 – 1961 Yuba City B-52 crash
  • USAF B-52 bomber experienced a decompression event that required it to fly below 10,000 feet. Resulting increased fuel consumption led to fuel exhaustion; the aircraft crashed with two nuclear bombs, which did not trigger a nuclear explosion.

• July 4, 1961 – coast of Norway – Near meltdown
  • The Soviet Hotel-class submarine K-19 suffered a failure in its cooling system. Reactor core temperatures reached 800 °C (1,500 °F), nearly enough to melt the fuel rods, although the crew was able to regain temperature control by using emergency procedures. The incident contaminated parts of the ship, some of the onboard ballistic missiles and the crew, resulting in several fatalities. The movie K-19: The Widowmaker, starring Harrison Ford and Liam Neeson, offers a controversially fictionalized story of these events.

• May 1, 1962 – Sahara desert, French Algeria – Accidental venting of underground nuclear test
  • The second French underground nuclear test, codenamed Béryl, took place in a shaft under mount Taourirt, near In Ecker, 150 km (100 mi) north of Tamanrasset, Algerian Sahara. Due to improper sealing of the shaft, a spectacular flame burst through the concrete cap and radioactive gases and dust were vented into the atmosphere. The plume climbed up to 2600 m (8500 ft) high and radiation was detected hundreds of km away. About a hundred soldiers and officials, including two ministers, were irradiated. The number of contaminated Algerians is unknown.

• April 10, 1963 – Loss of nuclear reactor
  • Submarine USS Thresher sinks about 190 nmi (220 mi; 350 km) east of Cape Cod, Massachusetts due to improper welds allowing in seawater which forced a shutdown of the reactor. Poor design of its emergency ballast system prevented the ship from surfacing and the disabled ship ultimately descended to crush depth and imploded.

• January 13, 1964 – Salisbury, Pennsylvania and Frostburg, Maryland, USA – Accidental loss and recovery of thermonuclear bombs
  • A USAF B-52 on airborne alert duty encountered a severe winter storm and extreme turbulence, ultimately disintegrating in mid-air over South Central Pennsylvania. Only the two pilots survived. One crew member failed to bail out and the rest succumbed to injuries or exposure to the harsh winter weather. A search for the missing weapons was initiated, and recovery was effected from portions of the wreckage at a farm northwest of Frostburg, MD.

• April 21, 1964 – Indian Ocean – Launch failure of a RTG powered satellite
  • A U.S. Transit-5BN-3 nuclear-powered navigational satellite failed to reach orbital velocity and began falling back down at 150,000 feet (46 km) above the Indian Ocean. The satellite's SNAP-9a generator contained 17 kCi (630 TBq) of 238Pu (2.1 pounds), which at least partially burned upon reentry. Increased levels of 238Pu were first documented in the stratosphere four months later. Indeed NASA (in the 1995 Cassini FEIS) indicated that the SNAP-9a plutonium release was nearly double the 9000Ci added by all the atmospheric weapons tests to that date. The United States Atomic Energy Commission reported a resulting threefold increase in global 238Pu fallout. All subsequent Transit satellites were fitted with solar panels; RTG's were designed to remain contained during re-entry.

• 8 December 1964 – Bunker Hill Air Force Base, USA – Fire, radioactive contamination
  • USAF B-58 aircraft carrying a nuclear weapon caught fire while taxiing. Nuclear weapon burned, causing contamination of the crash area.

• January 1965 – Livermore, California, USA – Release of nuclear materials
  • An accident at Lawrence Livermore National Laboratory released 300 kCi (11 PBq) of tritium gas. Subsequent study found this release was not likely to produce adverse health effects in the surrounding communities.

• 11 October 1965 – Rocky Flats Plant, Golden, Colorado, USA – Fire, exposure of workers
  • A fire at Rocky Flats exposed a crew of 25 to up to 17 times the legal limit for radiation.

• December 5, 1965 – coast of Japan – Loss of a nuclear bomb
  • A U.S. Navy A-4E Skyhawk aircraft with one B43 nuclear bomb on board fell off the aircraft carrier Ticonderoga into 16,200 feet (4,900 m) of water while the ship was underway from Vietnam to Yokosuka, Japan. The plane, pilot and weapon were never recovered. There is dispute over exactly where the incident took place—the U.S. Defense Department originally stated it took place 500 miles (800 km) off the coast of Japan, but Navy documents later show it happened about 80 miles (130 km) from the Ryukyu Islands and 200 miles (320 km) from Okinawa.

• January 17, 1966 – Palomares incident – Accidental destruction, loss and recovery of nuclear bombs
  • A USAF B-52 carrying four hydrogen bombs collided with a USAF KC-135 jet tanker during over-ocean in-flight refueling. Four of the B-52's seven crew members parachuted to safety while the remaining three were killed along with all four of the KC-135's crew. The conventional explosives in two of the bombs detonated upon impact with the ground, dispersing plutonium over nearby farms. A third bomb landed intact near Palomares while the fourth fell 12 miles (19 km) off the coast into the Mediterranean sea. The US Navy conducted a three month search involving 12,000 men and successfully recovered the fourth bomb. The U.S. Navy employed the use of the deep-diving research submarine DSV Alvin to aid in the recovery efforts. During the ensuing cleanup, 1,500 tonnes (1,700 short tons) of radioactive soil and tomato plants were shipped to a nuclear dump in Aiken, South Carolina. The U.S. settled claims by 522 Palomares residents for $600,000. The town also received a $200,000 desalinization plant. The motion picture Men of Honor (2000), starring Cuba Gooding, Jr., as USN Diver Carl Brashear, and Robert De Niro as USN Diver Billy Sunday, contained an account of the fourth bomb's recovery.

• January 21, 1968 – 1968 Thule Air Base B-52 crash, Greenland – Loss and partial recovery of nuclear bombs
  • A fire broke out in the navigator's compartment of a USAF B-52 near Thule Air Base, Greenland. The bomber crashed 7 miles (11 km) from the air base, rupturing its nuclear payload of four hydrogen bombs. The recovery and decontamination effort was complicated by Greenland's harsh weather. Contaminated ice and debris were buried in the United States. Bomb fragments were recycled by Pantex, in Amarillo, Texas. The incident caused outrage and protests in Denmark, as Greenland is a Danish possession and Denmark forbade nuclear weapons on its territory.

• May 22, 1968 – 740 km (400 nmi) southwest of the Azores – Loss of nuclear reactor and two W34 nuclear warheads
  • The USS Scorpion (SSN-589) sank while en route from Rota, Spain, to Naval Base Norfolk. The cause of sinking remains unknown; all 99 officers and men on board were killed. The wreckage of the ship, its S5W reactor, and its two Mark 45 torpedoes with W34 nuclear warheads, remain on the sea floor in more than 3,000 m (9,800 ft) of water.

• May 24, 1968 – location unknown – Loss of cooling, radioactive contamination, nuclear fuel damaged
  • During sea trials the Soviet nuclear submarine K-27 (Project 645) suffered severe problems with its reactor cooling systems. After spending some time at reduced power, reactor output inexplicably dropped and sensors detected an increase of gamma radiation in the reactor compartment to 150 rad/h. The safety buffer tank released radioactive gases further contaminating the submarine. The crew shut the reactor down and subsequent investigation found that approximately 20% of the fuel assemblies were damaged. The entire submarine was scuttled in the Kara Sea in 1981.

• August 27, 1968 – Severodvinsk, Russia (then USSR) – Reactor power excursion, contamination
  • While in the naval yards at Severodvinsk for repairs Soviet Yankee-class nuclear submarine K-140 suffered an uncontrolled increase of the reactor's power output. One of the reactors activated automatically when workers raised control rods to a higher position and power increased to 18 times normal, while pressure and temperature levels in the reactor increased to four times normal. The accident also increased radiation levels aboard the vessel. The problem was traced to the incorrect installation of control rod electrical cables.

• May 11, 1969 – Rocky Flats Plant, Golden, Colorado, USA – Plutonium fire, contamination
  • An accident in which 5 kilograms of plutonium burnt inside a glovebox at Rocky Flats. Cleanup took two years and was the costliest industrial accident ever to occur in the United States at that time.