List of nuclear accidents

Table of contents

1 1940s 2 1950s 3 1960s 4 1970s 5 1980s 6 1990s 7 2000s 8 Unconfirmed incidents 9 See also 10 External links

1940s

• May 21, 1945 - Canadian physicist Louis Slotin manually assembles a critical mass of plutonium while demonstrating his technique to visiting scientists at Los Alamos, New Mexico. The device conists of two half-spheres of beryllium-covered plutonium, which can be moved together slowly to measure the criticality. Normally the device would be operated by machinery, but Slotin distrusted it and instead operated it by holding the upper sphere like a bowling ball, with his thumb inserted into a hole in the top. Normally a number of washers would prevent the two from falling together completely, but he removed these. In order to slowly lower the two together he rested one edge on the lower sphere, and rotated a slot screwdriver between the other edge to control the separation. The screwdriver slipped and the assembly went critical while he was still holding into it. None of the seven observers received a lethal dose, but Slotin died on the 30th of massive radiation poisoning, with an estimated dose of 1,000 rad. This was dramatized in the movie Fat Man and Little Boy.

• February 12, 1952, Chalk River, Canada - first serious nuclear disaster in the NRX reactor. A massive power excursion destroyed the core, resulting in a partial meltdown. A series of hydrogen gas explosions threw the four-ton gasholder dome four feet into the air where it jammed in the superstructure. Thousands of curies of fission products were released into the atmosphere, and a million gallons of radioactively contaminated water had to be pumped out of the basement and "disposed of" in shallow trenches not far from the Ottawa River. The core was buried. Jimmy Carter, then a nuclear engineer in the US Navy, was among the cleanup crew.

• 1954 Off the Delaware/Maryland coast - The US Submarine Seawolf scuttles an experimental sodium-cooled reactor in 9,000 feet of water. It was not recovered. The reactor had problems with corrosion from the coolant, and was replaced by a conventional light-water reactor.

• July 2, 1956 - Nine individuals are injured after two explosions destroyed a portion of Sylvania Electric Products' Metallurgy Atomic Research Center in Bayside, Queens, New York.

• 1957 Keleket Co. - A capsule of radium salt bursts. This causes a five-month decontamination costing $250,000. The capsule was used to calibrate the radiation-measuring devices produced there.

• May 22, 1957 - Land grants of University of New Mexico, near Albuquerque, New Mexico. A bomber accidentally drops a 10 megaton hydrogen bomb. The trigger explosive detonates, creating a 12 foot deep crater 25 feet across. Some radiation is detected.

• September 29, 1957 - Cooling system failure resulted in a nuclear waste storage tank explosion at Mayak, a spent nuclear fuel reprocessing facility near Chelyabinsk, Russia, subjecting (by various estimates) 124,000 to 270,000 people to dangerously high levels of radiation. Of these, only 7,500 were evacuated, most of them too late to prevent dangerous levels of exposure. A series of less prominent accidents preceded and followed this meltdown, in addition to a polluted water supply for people remaining in the area. More than 500,000 inhabitants of the region have been exposed to radiation as a result.

• October 7, 1957 - A fire in the Windscale plutonium production reactor, north of Liverpool, England, cause the release of radioactive material, which is later blamed for 39 cancer deaths.

• January 31, 1958, U.S. Air-Force Base, 90 miles N.E. of Rabat, Morocco - A B-47 with a fully-armed nuclear weapon crashes and burns for 7 hours. The Air Force evacuates everyone within 1 mile of the base. Many vehicles and aircraft were contaminated. Moroccan officials were not notified.

• 1958, Chalk River, Canada several metallic uranium fuel rods in the NRU reactor overheated and ruptured inside the core. One of the damaged rods caught fire and was torn in two as it was being removed from the core by a robotic crane. As the remote-controlled crane passed overhead, carrying the larger portion of the damaged rod, a three-foot length of burning uranium fuel broke off and fell into a shallow maintenance pit. The ventilation system was jammed in the "open" position, thereby contaminating the accessible areas of the building as well as a sizable area downwind from the reactor site. A relay team of scientists and technicians eventually extinguished the fire by running past the maintenance pit at top speed wearing full protective gear, dumping buckets of wet sand on the burning uranium fuel.

• March 11, 1958, Hunter Air Force Base, Georgia - A B-47 en route to an overseas base drops an unarmed nuclear weapon into the yard of Walter Gregg and his family in Mars Bluff, South Carolina, near Florence, South Carolina. The trigger explodes and destroys Gregg's house, injuring six members of his family. The blast forms a crater 60 feet wide and 30 feet deep. Five houses and a church are also damaged. Five months later the Air Force pays the Greggs $54,000 of his estimated $300,000 loss. Residents carried away radioactive pieces of the bomb for souvenirs, which had to be retrieved by the Air Force cleanup crew.

• December 30, 1958 - A critical mass of plutonium solution is accidentally assembled during chemical purification at Los Alamos. The crane operator dies of acute radiation sickness. The March, 1961 Journal of Occupational Medicine prints a special supplement medically analyzing this accident. Hand-manipulations of critical assemblies are abandoned as a matter of policy in U.S. federal facilities after this accident.

• 1959 Santa Susana Field Laboratory near Simi Valley, California - A sodium-cooled reactor suffers a partial core meltdown.

• June 7, 1960 McGuire Air Force Base, New Egypt, New Jersey A helium tank explodes, rupturing the tanks of a BOMARC-A cruise missile. The fire melts the missile. The plutonium released from the nuclear trigger contaminates the facility and ground water.

• 1961 - The USS Theodore Roosevelt attempts to dump the depleted resin from its demineralization system (used to remove dissolved radioactive minerals and particles from the primary coolant loops of submarines). The ship is contaminated when wind blew the resin back onto the ship.

• January 3, 1961 National Reactor Testing Station, Idaho Falls, Idaho - An experimental reactor had a criticality incident, with a steam explosion and a severe dispersal of radioactive material, killing three workers at the installation. The radiation is contained. The experimental portable reactor had manually-moved control rods. Moving a single rod could cause the criticality incident. The rods were known to jam in the lightweight aluminum housing. Some investigators believe that a rod stuck and then suddenly released, causing the criticality incident. One worker was found pinned to the ceiling by a control rod, apparently driven by the steam.

• January 24, 1961, 12 miles north of Seymour Johnson Air Force Base, Goldsboro, North Carolina - A B-52 bomber explodes in mid-air. It releases two hydrogen bombs. Five crewmen parachuted to safety, three die. One bomb parachutes down, intact. The other plunges into mud. The area remains fenced, and tested regularly for radiation, although the state says that no radiation above background is present. See: [Broken Arrow: Goldsboro, NC http://www.ibiblio.org/bomb/].

• December 10, 1961 - An underground test nuclear explosion releases clouds of radioactive steam, causing several New Mexico highways to be closed.

• April 10, 1963, east of Boston, Massachusetts - The nuclear submarine USS Thresher sank during sea trials with 129 men aboard. A year earlier, just before the end of its refit interval, the boat had been abused in a munitions test where it literally tried to approach explosions as closely as possible. The boat was refitted afterward, and sank on its sea trials. In a show of poor planning, the sea trial was conducted where the bottom was below the hull's crush depth. In the yard, destructive tests of a few silver-soldered pipe connections had failed. At the time, nondestructive testing was unknown, and no test records were available. The investigators believed that the sinking was caused by the failure of a major through-hull silver-soldered connection, such as a secondary-loop cooling inlet, and that the reactor and its design was not responsible. The reactor was not recovered.

• July 24, 1964 - An accident at a commercial nuclear fuel fabrication facility in Charlestown, Rhode Island left one person dead.

• January 17, 1966, Palomares, Spain - During over-ocean in-flight refueling, a B-52 collides with an Air Force KC-135 jet tanker. Eight of the eleven crew members are killed. The KC-135's 40,000 gallons of jet fuel burn. Two hydrogen bombs rupture. The radioactive particles disperse over farms. An intact bomb lands near Palomares. The fourth bomb was lost at sea 12 miles off the coast. A search involving three months and 12,000 men recover it. 1,500 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 got a $200,000 desalinizing plant.

• October 5, 1966 - Near Detroit, Michigan a sodium cooling system malfunction caused a partial core meltdown at the Enrico Fermi demonstration nuclear breeder reactor. The radiation was contained. This incident is the basis of the controversial polemic We Almost Lost Detroit by John G. Fuller. Three plant workers were buried in lead-lined caskets.

• January 22, 1968, 7 miles S. of Thule Air Force Base, Greenland. A fire breaks out in the navigator's compartment of a B-52, which then crashes, scattering three hydrogen bombs on land, and dropping one into the sea. Contaminated ice and airplane debris were buried in the U.S. Bomb fragments were recycled by Pantex, in Amarillo, Texas. Danes were outraged (Greenland is a Danish possesion.) Denmark forbids nuclear weapons on its territory. Denmark had massive demonstrations against the U.S. One warhead was recovered by Navy Seals and Seabees (U.S. naval engineers) in 1979, An August 2000 report suggests that the other bomb remains at the bottom of Baffin Bay.

• May 21, 1968 - The USS Scorpion, a nuclear-powered attack submarine carrying two Mark 45 ASTOR torpedoes with nuclear warheads, was lost with 99 aboard. The nuclear material has not been recovered. The submarine has been photographed at the ocean bottom, and the U.S. Navy periodically monitors the location for radioactivity. Supposedly there has been no plutonium leakage to date.

• December 9, 1968, Nevada - An underground test of nuclear explosives releases clouds of radioactive steam.

• January 21, 1969 - A coolant malfunction from an experimental underground nuclear reactor at Lucens Vad, Switzerland, released a large amount of radiation into a cavern, which was then sealed.

• May 16, 1969, San Francisco, California, while being fitted the U.S.S. Guitarro, a nuclear submarine, sank because a forward compartment flooded.

• July 24, 1969, The AEC's Nuclear Trigger Assembly Facility, Rocky Flats, Colorado - a serious fire suspends U.S. missile production. Areas downwind were contaminated by plutonium. Several factory buildings became uninhabitable, were dismantled and buried.

• November 19, 1971 Northern States Power Company, Monticello, Minnesota - A nuclear power plant's water storage facility overflowed, releasing 50,000 gallons of radioactive waste water into the Mississippi River. Some radioactive substances entered the St. Paul water system.

• December 12, 1971, Thames river, near New London, Connecticut - Radioactive coolant water was being transferred from the submarine U.S.S. Dace to the sub tender U.S.S. Fulton when five hundred gallons were spilled.

• 1972, Nuclear Fuel Reprocessing Plant, West Valley, New York. After six years, the fuel reprocessing plant was closed. It left buried leaking tanks containing 600,000 gallons of high-level wastes. The waste contaminated Lake Erie and Lake Ontario.

• March 1972 - Senator Mike Gravel of Alaska submitted information to the Congressional Record. A routine check of a nuclear power plant showed radioactivity in the building's water, including the plant drinking fountain, which had been cross-connected with a 3,000 gallon tank of radioactive water.

• December 1972, Plutonium fabrication plant, Pauling, New York - A major fire and two explosions caused plutonium to contaminate the plant and grounds, resulting in its permanent shutdown.

• 1974 Isomedix Co, New Jersey - Workers report that radioactive water was flushed down toilets. The sewer pipes were contaminated. That year, in a different incident at the same company, a worker received a dose of radiation considered lethal, but was saved by prompt hospital treatment

• May 28, 1974 - The Atomic Energy Commission reports that 12 "abnormal events" in 1973 released radioactivity "above permissible levels" at nuclear power plants.

• 1975 - The USS Guardfish attempts to dump the depleted resin from its demineralization system (used to remove dissolved radioactive minerals and particles from the primary coolant loops of submarines). The ship is contaminated when wind blew the resin back onto the ship. This accident is fairly common (see 1961).

• March 22, 1975 - A fire at the Brown's Ferry nuclear reactor located in Decatur, Alabama causes a dangerous lowering of cooling water levels.

• October-November 1975 Apra Harbor, Guam - While disabled, the submarine tender USS Proteus discharged radioactive coolant water. A Geiger counter at two of the harbor's public beaches showed 100 millirems/hour, fifty times the allowable dose.

• January 24, 1978, Soviet nuclear-powered satellite Cosmos 954 crashes in Northwest Territories, Canada. Cleanup efforts recover some material, but much remains unreclaimed.

• May 22, 1978 near Puget Sound, Washington - Aboard the USS Puffer, a valve was mistakenly opened, releasing up to 500 gallons of radioactive water.

• March 28, 1979 - Equipment failures and worker mistakes contribute to a loss of coolant and a partial core meltdown at the Three Mile Island nuclear reactor in Middletown, Pennsylvania. This is the worst commercial nuclear accident in the United States to date.

• July 16, 1979, Church Rock, New Mexico - A dam holding uranium mill tailings broke. An estimated 100 million gallons of radioactive liquids and 1,100 tons of solid wastes moved downstream.

• September 19, 1980 - An Air Force repairman doing routine maintenance in a Titan II ICBM silo dropped a wrench socket, which rolled off a work platform and fell to the bottom of the silo. The socket struck the missile causing a leak from a pressurized fuel tank. The missile complex and surrounding area was evacuated. Eight and a half hours later, vapors within the silo ignited and exploded. The explosion fatally injured an Air Force specialist. Twenty-one other USAF personnel were injured.

• February 11, 1981 - A new worker inadvertently opens a valve more than 110,000 gallons of radioactive coolant liquid leaks into the containment building of the Tennessee Valley Authority Sequoyah 1 nuclear power plant in rural Tennessee. Eight workers are contaminated with radiation.

• November 2, 1981, U.S. Submarine Pens, Scotland - A fully-armed Poseidon missile was accidentally dropped 17 feet from a crane while being transferred from a submarine to its tender.

• April 25, 1981 - More than 100 workers are exposed to radiation during repairs of a nuclear power plant in Tsuruga, Japan.

• June, 1981, Salem 2 reactor, Salem, New Jersey - A 3,000 gallon leak of radioactive water.

• 1982 International Nutronics, of Dover, New Jersey - completely contaminates its plant, forcing its closure. IN used radiation to treat gems for color, modify chemicals, and sterilize food and medical supplies. A pump siphoned water from the baths to the floor. The water entered the sewer system of Dover. The NRC was informed of the accident ten months later, by a whistleblower.

• January 25, 1982 Rochester Gas & Electric Company's Ginna plant, Rochester, New York. A steam generator pipe breaks, spilling fifteen thousand gallons of radioactive coolant on the plant floor. Small amounts of radioactive steam escape into the air.

• February, 1982, Nuclear power plant, Salem, New Jersey - A 3,000 gallon leak of mildly radioactive water contaminates 16 workers.

• January 15-16, 1983 Nuclear power plant, Brown's Ferry, Tennessee - 207,000 gallons of low-level radioactive water is accidentally dumped into the Tennessee River.

• February 25, 1983 Nuclear power plant, Salem, New Jersey - The Salem 1 reactor fails to shut down automatically, but the operator detects the problem 90 seconds before an "incident" can occur. Automatic systems had failed to respond three days earlier. Salem 1 also experienced radioactive gas leaks in March 1981 and September 1982.

• August 1983, 3,700 liters of tritium leaked into Lake Huron and Lake Ontario from Canadian nuclear power stations.

• 1986, Hanford Engineering Works, Hanford, Washington - The U.S. Government declassified 19,000 pages of documents indicating that between 1946 and 1986 the Hanford Engineering Works released billions of gallons of radioactive liquids and billions of cubic meters of gases containing plutonium and other isotopes. Detrimental effects were noted as early as 1948, but reports critical of the facilities remained classified. Of 270,000 people living in the affected area, most received low doses of radiation from Iodine. About 13,500 received a dose 1,300 times the amount considered safe for civilians. Approximately 1,200 children received doses far in excess of this number.

• 1986, International Nutronics of Dover, New Jersey and one of its top executives are convicted by a federal jury of conspiracy and fraud. Radiation remains in the vicinity of the plant, but the NRC says the levels aren't hazardous.

• January 6, 1986 The Kerr-McGee nuclear fuel reprocessing plant in Gore, Oklahoma - a cylinder of nuclear material burst after being improperly heated. One worker dies, 100 are hospitalized.

• 1986 The NRC revokes the license of a Radiation Technology, Inc. (RTI) plant in New Jersey for worker safety violations. A safety device to prevent people from entering the irradiation chamber during operation was bypassed. A worker received a near-lethal dose of radiation. RTI was cited 32 times. Violations also included throwing radioactive garbage out with the regular trash.

• April 26, 1986 - The worst accident in the history of nuclear power occurred at the Chernobyl nuclear power plant located near Kiev, USSR (now part of the Ukraine). Fire and explosions resulting from an unauthorized experiment leave 31 dead in the immediate aftermath. Radioactive nuclear material is spread over much of Europe. Over 135,000 were evacuated from the areas around Chernobyl. Many of these areas remained uninhabitable for many years later.

• 1988, Savannah River, Georgia - The National Research Council panel released a report listing 30 "significant unreported incidents" at the Savannah River production plants over the previous 30 years. Ground water contamination occurred.

• June 6, 1988, Radiation Sterilizers, Decatur, Georgia - Reported a leak of Cesium-137 at their facility. Seventy thousand medical supply containers and milk cartons were recalled. Ten employees were exposed. Three "had enough on them that they contaminated other surfaces" including their homes and cars. (according to Jim Setser at the Georgia Department of Natural Resources.)

• October 1988, Nuclear trigger assembly facility, Rocky Flats, Colorado - Two employees and a 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.

• January, 1989, Savannah River, Georgia - A fault was discovered to run under the Savannah river nuclear processing plants, to an underground aquifer providing drinking water to much of the southeast. Nearby turtles had radioactive strontium of up to 1,000 times the background level.

• January 23, 1990, Bruce A, Ontario, Canada - 12,000 litres of heavy water are accidentially dumped into the containment vault below the reactor when a software failure releases the brakes on a refueling machine.

• November 24, 1992, Fuel Reprocessing Plant, Gore, Oklahoma - The plant closed after repeated safety and environmental violations. Its record during 22 years of operation included a 1986 accident that killed one worker and injured dozens of others, contamination of the Arkansas River and groundwater. It had been shut down the previous week by the Nuclear Regulatory Commission when an accident released toxic gas, causing thirty-four to seek medical attention. The plant had been shut down in 1991 when the water of a nearby construction pit had high concentrations of uranium. The government cited Carol Couch, the plant's environmental manager, for obstructing the investigation and falsifying documentation.

• February 15, 1993, 18,000 litres of heavy water are spilled at the Darlington nuclear power plant in Canada.

• May 1997, Hanford Engineering Works, Hanford, Washington - A 40 gallon tank of toxic chemicals exploded, causing a release of about 25,000 gallons of plutonium-contaminated water. Fluor Daniel Hanford Inc., was cited for violations of the Department of Energy's nuclear safety rules and fined $140,625. Violations included the contractor's failure to assure that breathing devices operated effectively, failure to make timely notifications of the emergency, and failure to conduct proper radiological surveys of workers, failure to assure adherence to "criticality" safety procedures. These procedures prevent the waste from acting like a reactor and generating more heat and radioactivity.

• August 8, 1999, Department of Energy's Gaseous Diffusion Isotope Separation Plant, Paducah, Kentucky - The Washington Post reported that thousands of workers were unwittingly exposed to plutonium and other highly radioactive metals over a 23-year period. Workers were told they were handling uranium rather than the more toxic plutonium. They inhaled radioactive dust as part of a government experiment to recycle used nuclear reactor fuel.

• September 30, 1999 - Japan's worst nuclear accident ever took place at a uranium reprocessing facility in Tokaimura, northeast of Tokyo, Japan. The direct cause of the accident was workers putting uranyl nitrate solution containing about 16.6 kg of uranium, which exceeded the critical mass, into the precipitation tank, which was not designed to dissolve this type of solution and was not configured to prevent eventual criticality. This exposed workers and residents in the surrounding area to extremely high levels of radiation.

• February 15, 2000 - The Indian Point II nuclear power plant in New York vented a small amount of radioactive steam when a steam generator failed.

• June 2000, Portsmouth Gaseous Diffusion Isotope Separation Plant, Piketon, Ohio - U.S. Senator Mike DeWine (R-OH) led a field senate hearing to discover evidence about on and off-site contamination. Testimony indicated that the Piketon plant altered workers' radiation dose readings and worked with medical professionals to fight worker's compensation claims.

• July 2000, Hanford Engineering Works, Hanford, Washington - Wildfires hit the highly radioactive "B/C" waste disposal trenches. Airborne plutonium levels were raised in the nearby cities of Pasco and Richland to 1,000 times above normal.

• August 2000, Barents Sea. The Russian submarine Kursk sank after an apparent internal torpedo accident, killing 118. Russia recovered the submarine's nuclear reactor, and stated it had carried no nuclear weapons. Greenpeace, urging Russia to recover the reactor, states there are now ten nuclear reactors and over fifty nuclear warheads on the floors of the world's oceans.

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