Leipzig L-IV experiment accident: Shortly after the Leipzig L-IV atomic pile – worked on by Werner Heisenberg and Robert Doepel – demonstrated Germany's first signs of neutron propagation, the device was checked for a possible heavy water leak. During the inspection, air leaked in, igniting the uranium powder inside. The burning uranium boiled the water jacket, generating enough steam pressure to blow the reactor apart. Burning uranium powder scattered throughout the lab causing a larger fire at the facility.[1][2]
While demonstrating his technique to visiting scientists at Los Alamos, Canadian physicistLouis Slotin manually assembled a critical mass of plutonium. A momentary slip of a screwdriver caused a prompt critical reaction. Slotin died on May 30 from massive radiation poisoning, with an estimated dose of 1,000 rads (rad), or 10 grays (Gy). Seven observers, who received doses as high as 166 rads, survived, yet three died within a few decades from conditions believed to be radiation-related.[4]
Slotin worked with the same bomb core as Daghlian which became known as the "demon core." It was later melted down and combined with existing weapons-grade material.
1950s
Date
Location
Type
Description
February 13, 1950
British Columbia
Loss of nuclear bomb/non-nuclear detonation of nuclear bomb
A simulated nuclear bomb containing TNT and uranium, but without the fissile core needed to create a nuclear explosion, was proactively dumped in the Pacific Ocean after a Convair B-36 bomber's engines caught fire during a test of its ability to carry nuclear payloads. The crew reported releasing the weapon out of concern for the amount of TNT inside, alone, before they bailed out of the aircraft. The bomber eventually crashed at an unknown location in Canada. Four years later the wreckage was found and searched, but no bomb was found. The weapon was briefly thought to have been located by a civilian diver in 2016 near Pitt Island but this was subsequently found not to be the case.[5]
A USAF B-36 bomber, AF Ser. No. 44-92075, was flying a simulated combat mission from Eielson Air Force Base, near Fairbanks, Alaska, to Carswell Air Force Base in Fort Worth, Texas, carrying one weapon containing a dummy warhead. The warhead contained conventional explosives and natural uranium but lacked the fissile core of an actual weapon. After six hours of flight, the bomber experienced mechanical problems and was forced to shut down three of its six engines at an altitude of 12,000 feet (3,700m). Fearing that severe weather and icing would jeopardize a safe emergency landing, the weapon was jettisoned over the Pacific Ocean from a height of 8,000ft (2,400m). The weapon's high explosives detonated upon impact with a bright flash visible. All of the sixteen crew members and one passenger were able to parachute from the plane and twelve were subsequently rescued from Princess Royal Island.[6] The accident was categorized as a Broken Arrow, that is an accident involving a nuclear weapon but which does not present a risk of war.[7]
Three minutes after departure from Kirtland Air Force Base in Albuquerque a USAF Boeing B-29 Superfortress carrying a nuclear weapon (without a fissile core), four spare detonators, and a crew of thirteen crashed into a mountain near Manzano Base. The crash resulted in a fire that The New York Times reported as being visible from 15 miles (24km). The bomb's casing was demolished and its high explosives ignited upon contact with the plane's burning fuel. However, according to the Department of Defense, the four spare detonators and all nuclear components, including a "dummy capsule" simulating a nuclear core, were recovered. All thirteen crew members died.[6]
A USAF B-50 aircraft on a training mission from Biggs Air Force Base with a nuclear weapon (without a nuclear core) flew into the ground resulting in a high-explosive detonation, but no nuclear explosion.[8]
A USAF B-29 bomber AF Ser. No. 44-87651 with a Mark 4 nuclear bomb (without a fissile core) on board, flying to Guam experienced malfunctions with two propellers and with landing gear retraction during take-off and crashed while attempting an emergency landing at Fairfield Suisun-AFB. In the resulting fire, the bomb's high-explosive material exploded, killing nineteen people from the crew and rescue personnel. Brigadier GeneralRobert F. Travis, command pilot of the bomber, was among the dead.[9]
The Castle Bravo fallout pattern.During the Castle Bravo test of the first deployable hydrogen bomb, a miscalculation resulted in the explosion being over twice as large as predicted, with a total explosive force of 15 megatons of TNT (63PJ). Of the total yield, 10Mt (42PJ) were from fission of the natural uranium tamper, but those fission reactions were quite dirty, producing a large amount of fallout. Combined with the much larger than expected yield and an unanticipated wind shift, radioactive fallout spread into unexpected areas. A Japanese fishing boat, the Daigo Fukuryu Maru/Lucky Dragon, came into contact with the fallout, which caused many of the crew to become ill, with one fatality. The fallout spread eastward onto the inhabited Rongelap and Rongerik Atolls. These islands were not evacuated before the explosion due to the unanticipated fallout zone and the financial cost involved, but many of the Marshall Islands natives have since suffered from radiation burns and radioactive dusting and also similar fates as the Japanese fishermen and have received little, if any, compensation from the federal government.[11] The test resulted in an international uproar and reignited Japanese concerns about radiation, especially with regard to the possible contamination of fish. Personal accounts of the Rongelap people can be seen in the documentary Children of Armageddon.
Operator error led to a partial core meltdown in the experimental EBR-Ibreeder reactor, resulting in temporarily elevated radioactivity levels in the reactor building and necessitating significant repair.[12][13]
A USAF B-47 Stratojet, AF Ser. No. 52-534, on a non-stop mission from MacDill Air Force Base, Florida, to an overseas base descended into a cloud formation at 14,000 feet over the Mediterranean in preparation for an in-air refueling and vanished while transporting two capsules of nuclear weapons material in carrying cases; a nuclear detonation was not possible.[14] A French news agency reported that the plane had exploded in the air Northeast of Saïdia, in French Morocco in the same general location of its last known position. The plane was lost while flying through dense clouds, and the cores and other wreckage were never located.[15][16][17]
A USAF B-47 crashed into a storage igloo, spreading burning fuel over three Mark 6 nuclear bombs at RAF Lakenheath. A bomb disposal expert stated it was a miracle exposed detonators on one bomb did not fire.[18] The weapons were in a storage configuration and there were no fissile capsules inside the weapons or the igloo.[19]
Non-nuclear detonation of a Mark 17 thermonuclear bomb[20]
A B-36 ferrying a nuclear weapon from Biggs AFB to Kirtland AFB dropped a thermonuclear weapon on approach to Kirtland. The weapon struck the ground 4.5 miles south of the Kirtland control tower and 0.3 miles west of the Sandia Base reservation. The weapon was completely destroyed by the detonation of its high explosive material, creating a crater 12 feet (3.7 m) deep and 25 feet (7.62 m) in diameter. Radioactive contamination at the crater lip amounted to 0.5 milliroentgen.[17] The aircraft contains a nuclear capsule, containing the fissile core for the weapon, but it was not installed in the weapon at the time of the accident, and was not involved in the explosion of the weapon.[19]
July 28, 1957
Atlantic Ocean
Two weapons jettisoned and not recovered
A USAF C-124 aircraft from Dover Air Force Base, Delaware was carrying three weapons and one nuclear capsule aboard the aircraft at the time. Nuclear components were not installed in the weapons. While flying over the Atlantic Ocean, the aircraft experienced a loss of power. For their own safety, the crew jettisoned two bombs which were never recovered.[8] Neither of the weapons detonated. The C-124 landed later with the other weapon and the nuclear capsule.[19]
A fire began in a theoretically fireproof area inside the plutonium processing building, in a glovebox used to handle radioactive materials, igniting the combustible rubber gloves and plexiglas windows of the box. The fire quickly spread to the plutonium as various safety features failed. The fire spread through the ventilation system as the containment ability of the facility became compromised, with plumes of radioactive smoke sent high into the outside air. The fire raged inside the building for 13 hours over the night of the 11th & 12th before firefighters could finally extinguish it. In the aftermath, Department of Energy officials, and the Dow Chemical officials who ran the facility, did not admit the extent of the catastrophe, or the radiation danger, to local officials or the media. Knowledge of the extent of the damage and contamination was kept from the public for years. After the fire, plutonium was detected near a school 12 miles (19km) away and around Denver17 miles (27km) away. An independent group of scientists conducting off-site testing 13 years later found plutonium contamination in areas in nearby Rocky Flats to be 400 to 1,500 times higher than normal, higher than any ever recorded near any urban area, including Nagasaki. The Atomic Energy Commission then conducted its own off-site study, and that study confirmed plutonium contamination as far as 30 miles (48km) from the plant.[21][22][23][24]
A cooling systemfailure at the Mayak nuclear processing plant resulted in a major explosion and release of radioactive materials. A large area was subjected to radioactive contamination and thousands of local inhabitants were evacuated.[25]
Technicians mistakenly overheated Windscale Pile No. 1 during an annealing process to release Wigner energy from graphite portions of the reactor. Poorly placed temperature sensors indicated the reactor was cooling rather than heating. The excess heat led to the failure of a nuclear cartridge, which in turn allowed uranium and irradiated graphite to react with air. The resulting fire burned for days, damaging a significant portion of the reactor core. About 150 burning fuel cells could not be removed from the core, but operators succeeded in creating a firebreak by removing nearby fuel cells. An effort to cool the graphite core with water and the switching off of the air cooling system eventually quenched the fire. The reactor had released radioactive gases into the surrounding countryside, primarily in the form of iodine-131 (131I). Milk distribution was banned in a 200-square-mile (520km2) area around the reactor for several weeks. A 1987 report by the National Radiological Protection Board predicted the accident would cause as many as 100 long-term cancer deaths, although the Medical Research Council Committee concluded that "it is in the highest degree unlikely that any harm has been done to the health of anybody, whether a worker in the Windscale plant or a member of the general public." The reactor that burned was one of two air-cooled, graphite-moderated natural uranium reactors at the site used for production of plutonium.[26][27][28] A 2007 study concluded that because the actual amount of radiation released in the fire could be double the previous estimates, and that the radioactive plume actually travelled further east, there were 100 to 240 cancer fatalities in the long term as a result of the fire.[29][30][31]
B-47 aircraft crashed during take-off after a wheel exploded; one nuclear bomb burned in the resulting fire.[32] The aircraft was carrying the unarmed weapon in a ferry configuration in the bomb bay, and a nuclear capsule in the crew compartment. Two "low-order" explosions occurred during the two hours that the plane and weapons burned. The nuclear capsule was recovered intact with minor damage.[19]
During a simulated takeoff, a wheel casting failure caused the tail of a USAF B-47 carrying a sealed-pit nuclear weapon to hit the runway, rupturing a fuel tank and sparking a fire. The high explosives in the weapon did not detonate, but some contamination was detected immediately following the accident.[32][33][34] After the accident, B-47 flights were temporarily suspended pending inspection of their wheels for defects.[19]
A USAF B-47 bomber jettisoned a Mark 15 Mod 0 nuclear bomb (the nuclear capsule was not aboard the aircraft; the bomb contained a simulated 150-pound (68 kg) capsule made of lead) over the Atlantic Ocean after a midair collision with a USAF F-86 Sabre during a simulated combat mission from Homestead Air Force Base, Florida. The F-86's pilot ejected and parachuted to safety.[35] The USAF claimed the B-47 tried landing at Hunter Air Force Base, Georgia three times before the bomb was jettisoned at 7,200ft (2,200m) near Tybee Island, Georgia. The B-47 pilot successfully landed in one attempt only after he first jettisoned the bomb. A 3-square-mile (7.8km2) area near Wassaw Sound was searched for nine weeks before the search was called off.
A B-47E of the 310th Bomb Wing developed problems shortly after takeoff and jettisoned its two 1,700 gallon external fuel tanks. They missed their designated safe impact area, and one hit a hangar while the other struck the ground 65 feet (20 m) behind a parked B-47E. The parked plane, which was fuelled, had a pilot on board, and was carrying a 1.1 megaton (4.6 PJ) B28 nuclear bomb, was engulfed by flames. The conflagration took sixteen hours and over a million gallons of water to extinguish, partly because of the magnesium alloys used in the aircraft. Although two men were killed and eight injured, the US and UK governments kept the accident secret: as late as 1985, the British government claimed that a taxiing aircraft had struck a parked one and that no fire was involved.
A USAF B-47E bomber, number 53-1876A, was flying from Hunter Air Force Base in Savannah, Georgia, to England in a formation of four B-47s on a top-secret mission called Operation Snow Flurry to perform a mock bombing exercise. The flight navigator/bombardier was checking the locking harness on the massive (7,600 pounds (3,447kg)) Mark 6 nuclear bomb when he accidentally pushed the emergency release lever. The bomb fell on the bomb-bay doors, smashing them open and going into a 15,000 feet (4,572m) free fall. The high-explosive detonator went off after it hit the ground 6.5 mileseast of Florence, South Carolina, in Mars Bluff, creating a 70 feet (21m) wide crater, 30 feet (9m) deep.[36] A nearby house was destroyed and several people were injured.[35]:136–137[37] The weapon did not have an installed nuclear capsule at the time of the accident, and so a nuclear detonation was not possible. There was a nuclear capsule onboard the plane, in another section of the aircraft.[19]
A supercritical portion of highly enriched uranyl nitrate was allowed to collect in the drum causing a prompt neutron criticality in the C-1 wing of building 9212 at the Y-12 complex. It is estimated that the reaction produced 1.3×1018 fissions. Eight employees were in close proximity to the drum during the accident, receiving neutron doses ranging from 30 to 477 rems. No fatalities were reported.[38]
A USAF B-47 bomber developed a fire shortly after take-off and went down with a sealed-pit nuclear weapon on board from an altitude of 1,500ft (460m). The detonation of the high explosive material in the bomb created a crater 6 feet (1.8 m) deep and 35 feet (10.7 m) in diameter. Three crew members escaped, and one was killed.[39] All weapons components were ultimately accounted for, after digging for them in the crater.[19]
A USAF B-47 bomber with a nuclear weapon on board developed a fire while on the ground. The aircraft wreckage and the site of the accident were contaminated after a limited explosion of non-nuclear material.[40]
A parked USAF F-100C Super Sabre, loaded with a nuclear weapon, developed a fire after its external fuel tanks were dropped and exploded during a practice alert. The resulting fire was put out in seven minutes and there was no nuclear explosion.[41] When originally disclosed in 1980, the location was originally identified as at a base in the Pacific region. In 2016, the newspaper Asahi Shimbun reported that the location of the accident was Osan Air Base.[42]
A USAF C-124 transporting three Mark 39 Mod 2 sealed-pit nuclear weapons crashed and burned down during take-off. The high explosives did not detonate, but one weapon was completely destroyed by the fire, and the other two suffered heat damage and tritium leakage. The wreckage area experienced limited contamination.[43]
A U.S. Navy P5Mantisubmarine aircraft patrolling out of NAS Whidbey Island with an unarmed Mark 90 nuclear depth charge casing on board crash-landed in the Pacific Ocean, about 100 miles (160 km) west of the Washington-Oregon border.[44] The casing was not recovered.[45]
A leak developed in the steam generators and in a pipe leading to the compensator reception on the ill-fated K-8 while the SovietNorthern FleetNovember-classsubmarine 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).[48]
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 (69,000kPa) struck the top of the reactor vessel propelling the entire reactor vessel upwards over 9 feet (2.7m) 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.
A USAF B-52bomber caught fire and exploded in midair due to a major leak in a wing fuel cell 12 miles (19km) north of Seymour Johnson Air Force Base, North Carolina. Five crewmen parachuted to safety, but three others died—two in the aircraft and one on landing. The incident released the bomber's two Mark 39 nuclear 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 (30m) 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 700mph (300m/s) and disintegrated. Its tail was discovered about 20 feet (6m) 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 on site. It is estimated to lie around 55 feet (17m) 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.[49]
USAF B-52bomber departed Mather Air Force Base, California and experienced a decompression event that required it to fly below 10,000 feet. Resulting increased fuel consumption led to fuel exhaustion; the aircraft crashed near Yuba City, California with two nuclear bombs, which did not trigger a nuclear explosion.
The SovietHotel-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 film K-19: The Widowmaker, starring Harrison Ford and Liam Neeson, offers a controversially fictionalized story of these events.[citation needed]
The second French underground nuclear test, codenamed Béryl, took place in a shaft under Mount Taourirt, near In Ecker, 150km (93mi) 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 2,600m (8,500ft) high and radiation was detected hundreds of kilometers away. About a hundred soldiers and officials, including two ministers, were irradiated. The number of contaminated Algerians is unknown.
Titan I ICBM explodes in its silo in Chico, California.[50] During a contractor checkout, a leak and subsequent explosion occurred at launcher 1 at complex 4C at Chico, destroying a Titan I and causing heavy damage to the silo. The Air Force concluded that the two separate explosions occurred because of a blocked vent and blocked valve. All contractors and crew of the silo escaped unharmed.
June 20, 1962
Johnson Island
Self-destruction of nuclear-armed Thor missile
Part of the Starfish test series by the US military, a Thor missile was launched but had its flight aborted one minute after its takeoff. No nuclear explosion took place. However, heavily contaminated missile components fell back down upon the island where service personnel worked and lived.
July 25, 1962
Johnson Island
Explosion of nuclear-armed Thor missile
The Thor missile exploded on its launchpad, scattering highly contaminated debris all over the island. Service personnel were heavily exposed to radiation both during the explosion and in subsequent emergency clean-up efforts. Veterans who were exposed to the high radiological hazards all suffered lethal long-term effects of radiation-based cancers.
April 10, 1963
Loss of nuclear reactor
Submarine USSThresher sinks about 190nmi (220mi; 350km) east of Cape Cod, Massachusetts due to improper welds allowing in seawater which forced a shutdown of the reactor. Poor design of its emergency blow system prevented the ship from surfacing and the disabled ship ultimately descended to crush depth and imploded, killing all 129 on board. Wreckage remains on the sea floor at 8,400 feet (2,600 m) below the surface
USAF B-52 on airborne alert duty encountered a severe winter storm and extreme turbulence, ultimately disintegrating in midair over South Central Pennsylvania.[51] 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.
Warhead separated in the launch tube due to an electrical short circuit and fell to the bottom of the tube. At launch facility Lima-02 near Vale, South Dakota. The missile site was part of the former 44th Missile Wing at Ellsworth AFB, South Dakota.[52]
USAF B-58 aircraft carrying a B53 nuclear bomb internally, and four B43 nuclear bombs externally, caught fire while taxiing after its landing gear collapsed. The B53 burned, causing contamination of the crash area. Two of the B43s caused some plutonium and uranium contamination.[8][53]
An accident at Lawrence Livermore National Laboratory released 300kCi (11 PBq) of tritium gas. Subsequent study found this release was not likely to produce adverse health effects in the surrounding communities.[54]
A USAF B-52 carrying four hydrogen bombs collided with a USAF KC-135jet 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, Almería (Spain) while the fourth fell 12 miles (19km) off the coast into the Mediterranean sea. The U.S. 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 DSVAlvin 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, Master Chief Petty Officer Carl Brashear, and Robert De Niro as USN Diver, Chief Petty Officer Billy Sunday, contained an account of the fourth bomb's recovery.[57]
A fire broke out in the navigator's compartment of a USAF B-52 near Thule Air Base, Greenland. The bomber crashed 7 miles (11km) from the airbase, rupturing the bomber's bomb bay and causing the conventional explosives in the four B28FI thermonuclear bombs to detonate, fragmenting and spreading the radioactive primary and secondary components across a large area. The burning bomber and its fuel load melted through the ice, dropping wreckage to the seafloor underneath. The recovery and decontamination effort was complicated by Greenland's harsh weather. Contaminated ice and debris were returned and buried in the United States. Recovered 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.
March 8, 1968
1,560 nautical miles (2,890 km) northwest of Oahu in the Pacific Ocean
?
The Soviet nuclear submarine K-129 sank with a crew of 98 due to an explosion of unknown cause. The International Atomic Energy Agency stated that two nuclear warheads from K-129 were located in the Pacific 1,230 miles from Kamchatka at coordinates 40°6'N and 179°57'E at a depth of 6,000 metres (20,000 ft), and lists them as recovered.
Loss of nuclear reactor and two W34 nuclear warheads
Mark 45 nuclear torpedo, similar to the two that were lostThe U.S.submarineUSSScorpion sank while en route from Rota, Spain, to Norfolk, Virginia, United States. The cause of sinking remains unknown; all 99 officers and men on board were killed. Scorpion's original "full overhaul" was reduced in scope. Long-overdue SUBSAFE work, such as a new central valve control system, was not performed. The wreckage of the submarine, its S5Wnuclear reactor, and its two Mark 45 torpedoes with W34 nuclear warheads, remain on the sea floor in more than 3,000m (9,800ft) of water.
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.
While in the naval yards at Severodvinsk for repairs, the Soviet Yankee-classnuclear submarineK-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.
An accident in which 5kilograms 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.[58][59][60]
The Soviet November-classattack submarineK-8 sank during salvage with 52 sailors on board after suffering fires in two compartments simultaneously. Both reactors were shut down. The crew attempted to hook a tow line to an Eastern Blocmerchant vessel, but ultimately failed.[61]
Baneberry's radioactive plume rises from a shock fissure. Contaminants were carried in three different directions by the wind.The Partial Nuclear Test Ban Treaty of 1963 was meant to prevent the nuclear fallout freely associated with the earlier above ground tests. Some venting might still happen on site, but the 1970 "Baneberry" test blast – part of Operation Emery– resulted in extensive off-site fallout. The 10-kiloton "Baneberry" test took place under Area 8 on Yucca Flat. The weapon detonated as planned at the bottom of a sealed vertical shaft 900ft (270m) below the Earth's surface, but the device's energy cracked the soil in unexpected ways, causing a fissure near ground zero and releasing a plume of hot gases and radioactive dust that continued for many hours, raining fallout on workers within NTS.[62][63] Six percent of the explosion's radioactive products were vented, releasing 6.7 MCi of radioactive material, including 80 kCi of Iodine-131 and a high ratio of noble gases.[64] The hot cloud's lighter particles were carried to three altitudes by three diverging jet stream layers and conveyed by winter storms and the jet stream to be deposited heavily as radionuclide-laden snow in Lassen and Sierra counties in northeast California, and to lesser degrees in northern Nevada, southern Idaho and some eastern sections of Oregon and Washington states.[65] The three diverging jet stream layers conducted radionuclides across the U.S. to Canada, the Gulf of Mexico and the Atlantic Ocean. Some 86 workers at the site were exposed to radioactivity, but according to the Department of Energy, none received a dose exceeding site guidelines and, similarly, radiation drifting offsite was not considered to pose a hazard by the DOE.[66] In March 2009, TIME magazine identified the Baneberry Test as one of the world's worst nuclear disasters.[67]
During the transfer of radioactive coolant water from the submarine USSDace to the submarine tenderUSSFulton500 US gallons (1,900L; 420impgal) were spilled into the Thames River (US).
Radioactive resin contaminates the AmericanSturgeon-class submarineUSSGuardfish after wind unexpectedly blows the powder back towards the ship. The resin is used to remove dissolved radioactive minerals and particles from the primary coolant loops of submarines. This type of accident was fairly common; however, U.S. Navy nuclear vessels no longer discharge resin at sea.[citation needed]
While disabled, the submarine tender USSProteus discharged radioactive coolant water. A Geiger counter at two of the harbor's public beaches showed 100 millirems/hour, fifty times the allowable dose.[71][72]
An explosion at the Hanford site Plutonium Finishing Plant blew out a quarter-inch-thick lead glass window. Harold McCluskey, a worker, was showered with nitric acid and radioactive glass. He inhaled the largest dose of 241Am ever recorded, about 500 times the U.S. government occupational standards. The worker was placed in isolation for five months and given an experimental drug to flush the isotope from his body. By 1977, his body's radiation count had fallen by about 80 percent. He died of natural causes in 1987 at age 75.[73]
Kosmos 954, a Soviet Radar Ocean Reconnaissance Satellite with an onboard nuclear reactor, failed to separate from its booster and broke up on reentry over Western and Northern Canada. The fuel was spread over a wide area and some radioactive pieces were recovered. The Soviet Union eventually paid the Canadian government $3 million CAD ($13 million today) for expenses relating to the crash.
At about 6:30p.m., an airman conducting maintenance on a USAF Titan-II missile at Little Rock Air Force Base's Launch Complex 374-7 in Southside (Van Buren County), just north of Damascus, Arkansas, dropped a nine-pound (4kg)socket from a socket wrench, which fell about 80 feet (24m) before hitting and piercing the skin on the rocket's first-stage fuel tank, causing it to leak. The area was evacuated. Overnight, at about 3:00 a.m., the hypergolic fuel exploded. The W53 warhead landed about 100 feet (30m) from the launch complex's entry gate; its safety features operated correctly and prevented any explosion, chemical or nuclear. An Air Force airman, David Livingston, was killed and the launch complex was destroyed.[75]
The Andreev Bay nuclear accident was associated with leaks in a massive cooling and storage pool. The leaks caused about 700,000 tonnes of highly radioactive water to leak into the Barents Sea during that time period. During the extensive period of attempted repairs and subsequent dismantling of the pool, other incidents occurred on site, including accidental accumulations of critical masses of material releasing radiation and an "industrial accident" that caused two cleanup workers to plunge directly into the radioactive pool.
While on duty in the Barents Sea, there was a release of liquid metal coolant from the reactor of the Soviet Project 705 Alfa-class submarineK-123. The accident was caused by a leak in the steam generator. Approximately two tons of metal alloy leaked into the reactor compartment, irreparably damaging the reactor so it had to be replaced. It took nine years to repair the submarine.
January 3, 1983
South Atlantic
Contamination
The Soviet nuclear-powered spy satellite Kosmos 1402 burned up over the South Atlantic.
About 35 miles (56km) from Vladivostok in Chazhma Bay, the SovietEcho-classsubmarineK-431 suffered a reactor explosion, producing fatally high levels of radiation. Ten men were killed, but the deadly cloud of radioactivity did not reach Vladivostok.[76]
The U.S. government declassified 19,000 pages of documents indicating that between 1946 and 1986, the Hanford Site near Richland, Washington, released thousands of US gallons of radioactive liquids. Many of the people living in the affected area received low doses of radiation from 131I.
October 3, 1986
North Atlantic
Loss of two nuclear reactors and either 32 or 48 warheads[77][78][79][nb 1]
480 miles (770km) east of Bermuda, the Soviet Yankee I-classsubmarineK-219 experienced an explosion in one of its missile tubes and at least three crew members were killed. Sixteen nuclear missiles and two reactors were on board. Soviet leaderMikhail Gorbachev privately communicated news of the disaster to U.S. President Ronald Reagan before publicly acknowledging the incident on October 4. Two days later, on October 6, the submarine sank in the Atlantic Ocean while under tow in 18,000 feet (5,500m) of water.[80]
October 1988
Rocky Flats Plant, Golden, Colorado, US
Contamination, exposure of workers
At the nuclear pit fabrication facility at Rocky Flats in Colorado, two employees and a United States Department of Energy inspector inhaled radioactive particles, causing closure of the plant. Several safety violations were cited, including uncalibrated monitors, inadequate fire equipment, and groundwater contaminated with radioactivity.
Soldiers suffered radiation poisoning and burns. They were eventually traced back to training sources abandoned, forgotten, and unlabeled after the dissolution of the Soviet Union. One was a 137Cs pellet in a pocket of a shared jacket which put out about 130,000 times the level of background radiation at a one-metre (3.3ft) distance.[81]
During the final testing of a new saltless uranium processing method, there was a small explosion followed by a fire. The explosion occurred in an unvented vessel containing unreacted calcium, water and depleted uranium. An exothermic reaction in the vessel generated enough steam to burst the container. This small explosion breached its glovebox, allowing air to enter and ignite some loose uranium powder. Three employees were contaminated. BWXT Y-12 (now B&W Y-12), a partnership of Babcock & Wilcox and Bechtel, was fined $82,500 for the accident.[82]
↑ The missiles involved in the accident must have been the R-27U version as the original version was retired by 1983. Sources given conflicting numbers on the number of warheads carried by the R-27U, either two or three.
↑ Norris, Robert S.; Arkin, William M.; Burr, William (1999). "Where they were"(PDF). Bulletin of the Atomic Scientists. 55 (6): 26–35. doi:10.2968/055006011.
↑ "1957 Fire"(PDF). Citizen Summary: Rocky Flats Historical Public Exposures Studies. Archived from the original(PDF) on 2021-06-24. Retrieved 2007-06-17.
↑ Gibson, James N. Nuclear Weapons of the United States – An Illustrated History. Atglen, PA: Schiffer Publishing Ltd., 1996, LCCN96-67282, ISBN0-7643-0063-6, Chapter 12, "Nuclear Anti-Submarine Weapons", p. 214.
↑ Snider, Laura (2009-05-10). "Looking back on Mother's Day fire at Rocky Flats". Boulder & County News. Boulder Daily Camera. Archived from the original on May 12, 2009. Retrieved 2009-07-26. On Mother's Day in 1969... the worst industrial conflagration the country had ever seen... when Building 776–777 on the Rocky Flats campus eight miles south of Boulder caught fire...
↑ Moore, LeRoy (January 2006). "Guilt or innocence at Rocky Flats"(PDF). NUCLEAR NEXUS» Local Hazards» Rocky Flats. Rocky Mountain Peace and Justice Center. Archived from the original(PDF) on August 21, 2008. Retrieved 2009-07-26. A fire at Rocky Flats on Mother's Day, May 11, 1969, turned out to be the worst industrial fire to date in US history.
↑ Lluma, Diego (May–June 2000). "Former Soviet Union: What the Russians left behind". Bulletin of the Atomic Scientists. 56 (3): 14–17. doi:10.2968/056003005. S2CID145248534.
(in French) Jean-Hugues Oppel, Réveillez le président!, Éditions Payot et rivages, 2007 ( ISBN978-2-7436-1630-4). The book is a fiction about the nuclear weapons of France; the book also contains about ten chapters on true historical incidents involving nuclear weapons and strategy (during the second half of the twentieth century).
A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either fission or a combination of fission and fusion reactions, producing a nuclear explosion. Both bomb types release large quantities of energy from relatively small amounts of matter.
Nuclear fallout is residual radioactive material propelled into the upper atmosphere following a nuclear blast, so called because it "falls out" of the sky after the explosion and the shock wave has passed. It commonly refers to the radioactive dust and ash created when a nuclear weapon explodes. The amount and spread of fallout is a product of the size of the weapon and the altitude at which it is detonated. Fallout may get entrained with the products of a pyrocumulus cloud and when combined with precipitation falls as black rain, which occurred within 30–40 minutes of the atomic bombings of Hiroshima and Nagasaki. This radioactive dust, usually consisting of fission products mixed with bystanding atoms that are neutron-activated by exposure, is a form of radioactive contamination.
Acute radiation syndrome (ARS), also known as radiation sickness or radiation poisoning, is a collection of health effects that are caused by being exposed to high amounts of ionizing radiation in a short period of time. Symptoms can start within an hour of exposure, and can last for several months. Early symptoms are usually nausea, vomiting and loss of appetite. In the following hours or weeks, initial symptoms may appear to improve, before the development of additional symptoms, after which either recovery or death follow.
The Nevada National Security Sites, popularized as the Nevada Test Site (NTS) until 2010, is a reservation of the United States Department of Energy located in the southeastern portion of Nye County, Nevada, about 65 mi (105 km) northwest of the city of Las Vegas.
Nuclear weapons tests are experiments carried out to determine the performance, yield, and effects of nuclear weapons. Testing nuclear weapons offers practical information about how the weapons function, how detonations are affected by different conditions, and how personnel, structures, and equipment are affected when subjected to nuclear explosions. However, nuclear testing has often been used as an indicator of scientific and military strength. Many tests have been overtly political in their intention; most nuclear weapons states publicly declared their nuclear status through a nuclear test.
A nuclear and radiation accident is defined by the International Atomic Energy Agency (IAEA) as "an event that has led to significant consequences to people, the environment or the facility." Examples include lethal effects to individuals, large radioactivity release to the environment, or a reactor core melt. The prime example of a "major nuclear accident" is one in which a reactor core is damaged and significant amounts of radioactive isotopes are released, such as in the Chernobyl disaster in 1986 and Fukushima nuclear disaster in 2011.
The United States is known to have possessed three types of weapons of mass destruction: nuclear, chemical, and biological weapons. As the country that invented nuclear weapons, the U.S. is the only country to have used nuclear weapons on another country, when it detonated two atomic bombs over two Japanese cities of Hiroshima and Nagasaki during World War II. It had secretly developed the earliest form of the atomic weapon during the 1940s under the title "Manhattan Project". The United States pioneered the development of both the nuclear fission and hydrogen bombs. It was the world's first and only nuclear power for four years, from 1945 until 1949, when the Soviet Union produced its own nuclear weapon. The United States has the second-largest number of nuclear weapons in the world, after the Russian Federation.
The Tybee Island mid-air collision was an incident on February 5, 1958, in which the United States Air Force lost a 7,600-pound (3,400 kg) Mark 15 nuclear bomb in the waters off Tybee Island near Savannah, Georgia, United States. During a night practice exercise, an F-86 fighter plane collided with the B-47 bomber carrying the large weapon.
The Palomares incident occurred on 17 January 1966, when a B-52G bomber of the United States Air Force's Strategic Air Command collided with a KC-135 tanker during mid-air refueling at 31,000 feet (9,450 m) over the Mediterranean Sea, off the coast of Spain. The KC-135 was destroyed when its fuel load ignited, killing all four crew members. The B-52G broke apart, killing three of the seven crew members aboard.
The United States was the first country to manufacture nuclear weapons and is the only country to have used them in combat, with the bombings of Hiroshima and Nagasaki in World War II. Before and during the Cold War, it conducted 1,054 nuclear tests, and tested many long-range nuclear weapons delivery systems.
Since the mid-20th century, plutonium in the environment has been primarily produced by human activity. The first plants to produce plutonium for use in Cold War atomic bombs were the Hanford nuclear site in Washington, and the Mayak nuclear plant, in Chelyabinsk Oblast, Russia. Over a period of four decades, "both released more than 200 million curies of radioactive isotopes into the surrounding environment – twice the amount expelled in the Chernobyl disaster in each instance."
The United States Armed Forces uses a number of terms to define the magnitude and extent of nuclear and radiation accidents and incidents in order to reduce the time taken to report the type of incident, thus streamlining the radio communications in the wake of the event.
On 21 January 1968, an aircraft accident, sometimes known as the Thule affair or Thule accident, involving a United States Air Force (USAF) B-52 bomber occurred near Thule Air Base in the Danish territory of Greenland. The aircraft was carrying four B28FI thermonuclear bombs on a Cold War "Chrome Dome" alert mission over Baffin Bay when a cabin fire forced the crew to abandon the aircraft before they could carry out an emergency landing at Thule Air Base. Six crew members ejected safely, but one who did not have an ejection seat was killed while trying to bail out. The bomber crashed onto sea ice in North Star Bay, Greenland, causing the conventional explosives aboard to detonate and the nuclear payload to rupture and disperse, resulting in radioactive contamination of the area.
In nuclear weapon design, the pit is the core of an implosion nuclear weapon, consisting of fissile material and any neutron reflector or tamper bonded to it. Some weapons tested during the 1950s used pits made with uranium-235 alone, or as a composite with plutonium. All-plutonium pits are the smallest in diameter and have been the standard since the early 1960s. The pit is named after the hard core found in stonefruit such as peaches and apricots.
These are lists of nuclear disasters and radioactive incidents.
The United States Government Accountability Office reported more than 150 incidents from 2001 to 2006 of nuclear plants not performing within acceptable safety guidelines. According to a 2010 survey of energy accidents, there have been at least 56 accidents at nuclear reactors in the United States. The most serious of these was the Three Mile Island accident in 1979. Davis-Besse Nuclear Power Plant has been the source of two of the top five most dangerous nuclear incidents in the United States since 1979. Relatively few accidents have involved fatalities.
The Rocky Flats Plant, a former United States nuclear weapons production facility located about 15 miles (24 km) northwest of Denver, caused radioactive contamination within and outside its boundaries. The contamination primarily resulted from two major plutonium fires in 1957 and 1969 and from wind-blown plutonium that leaked from barrels of radioactive waste. Much lower concentrations of radioactive isotopes were released throughout the operational life of the plant from 1952 to 1992, from smaller accidents and from normal operational releases of plutonium particles too small to be filtered. Prevailing winds from the plant carried airborne contamination south and east, into populated areas northwest of Denver.
Nuclear ethics is a cross-disciplinary field of academic and policy-relevant study in which the problems associated with nuclear warfare, nuclear deterrence, nuclear arms control, nuclear disarmament, or nuclear energy are examined through one or more ethical or moral theories or frameworks.
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