U.S. Nuclear Accidents


The following is a compilation of some known events involving nuclear devices and facilities under U.S. jurisdiction, many involving fatalities. Note that this work is NOT an anti-nuclear diatribe, but rather an encyclopedic listing of facts pertaining to a particular topic; I am well aware of the dangers and negative ecological consequences of alternate energy forms (especially coal and petroleum-based fuels), but a discussion of those is beyond the subject matter of this page.

Please DO NOT mail me with requests for additional information; all that i know about this subject is presented on this page, and i regret that i am unable to assist the internet community with additional information on this topic. More information along these lines is available at the following:

Also highly recommended is Eric Schlosser's 2013 book Command and Control: Nuclear Weapons, The Damascus Accident, and the Illusion of Safety.

Please feel free to submit additions or corrections to me at allen@lutins.net.

Buy Me A Coffee


Definition of Nuclear Accidents

The Department of Defense Report Narrative Summaries of Accidents Involving U.S. Nuclear Weapons 1950-1980 defines an "accident involving nuclear weapons" as "An unexpected event involving nuclear weapons or nuclear weapons components that results in any of the following:" I have closely followed this definition, but expanded it to include research facilities, power plants, processing facililties, and other military and civilian contexts.

Research Facilities

2 September 1944
Peter Bragg and Douglas Paul Meigs, two Manhattan Project chemists, were killed when their attempt to unclog a tube in a uranium enrichment device led to an explosion of radioactive uranium hexafluoride gas exploded at the Naval Research Laboratory in Philadelphia, PA. The explosion ruptured nearby steam pipes, leading to a gas and steam combination that bathed the men in a scalding, radioactive, acidic cloud of gas which killed them a short while later.

21 August 1945
Harry K. Daghlian Jr. was killed during the final stages of the Manhattan Project (undertaken at Los Alamos, New Mexico to develop the first atomic bomb) from a radiation burst released when a critical assembly of fissile material was accidentally brought together by hand. This incident pre-dated remote-control assembly of such components, but the hazards of manual assembly were known at the time (the accident occurred during a procedure known as "tickling the dragon's tail"). A similar incident, involving another fatality, occurred the following year (see next entry), after which hand-maniuplations of critical assemblies was abandoned.

21 May 1946 A nuclear criticality accident occured at the Los Alamos Scientific Laboratory in New Mexico when worker Louis Slotin accidentally dropped a screwdriver while sealing a core for a Mark 3 nuclear bomb. Eight people were exposed to radiation, and Slotin died nine days later of acute radiation sickness.

29 November 1955
EBR (Experimental Breeder Reactor) I, located near Arco, Idaho, experienced a partial core meltdown. EBR I, which commenced operating in 1951 and was decommissioned in 1964, was the world's first nuclear power plant.

2 July 1956
Nine persons were injured when two explosions destroyed a portion of Sylvania Electric Products' Metallurgy Atomic Research Center in Bayside, Queens, New York.

A radiation release at the the Keleket company resulted in a five-month decontamination at a cost of $250,000. A capsule of radium salt (used for calibrating the radiation-measuring devices produced there) burst, contaminating the building for a full five months.

30 December 1958
A chemical operator was exposed to a lethal dose of radiation following an incident involving the mixing of plutonium solutions, dying 35 hours later of severe radiation exposure.

26 July 1959
A clogged coolant channel resulted in damage to 30% of the fuel elements at the Santa Susana Field Laboratory (now known as the Boeing-Rocketdyne Nuclear Facility) in the Simi Hills area of Ventura County, California. Later discovery of the incident prompted a class-action suit by local residents, who successfully sued for $30 million over cancer and thyroid abnormalities contracted due to their proximity to the facility. The incident is described in greater detail in an article at the Pacific Standard

2 April 1962
An "unplanned nuclear excursion" occurred in a plutonium processing facility in Richland, Washington. Several employees were hospitalized for observation following exposure to the resultant radiation, and radiation was detected in the surrounding atmosphere for several days following the incident.

26 March 1963
A mechanical failure led to a nuclear leak and subsequent fire at an experimental facility in Livermore, California, resulting in serious damage to the shielded vault where the experiment was conducted.

5 October 1966
A sodium cooling system malfunction caused a partial core meltdown at Detroit Edison's Enrico Fermi I demonstration breeder reactor near Detroit, Michigan. Radioactive gases leaked into the containment structures, but radiation was reportedly contained. The incident is documented in John Fuller's We Almost Lost Detroit.

Whistleblowers at the Isomedix company in New Jersey reported that radioactive water was flushed down toilets and had contaminated pipes leading to sewers. The same year a worker received a dose of radiation considered lethal, but was saved by prompt hospital treatment.

International Nutronics in Dover, New Jersey, which used radiation baths to purify gems, chemicals, food, and medical supplies, experienced an accident that completely contaminated the plant, forcing its closure. A pump malfunctioned, siphoning water from the baths onto the floor; the water eventually was drained into the sewer system of the heavily populated town of Dover. The NRC wasn't informed of the accident until ten months later – and then by a whistleblower, not the company. In 1986, the company and one of its top executives were convicted by a federal jury of conspiracy and fraud. Radiation has been detected in the vicinity of the plant, but the NRC claims the levels "aren't hazardous."

The NRC revoked the license of a Radiation Technology, Inc. (RTI) plant in New Jersey for repeated worker safety violations. RTI was cited 32 times for various violations, including throwing radioactive garbage out with the regular trash. The most serious violation was bypassing a safety device to prevent people from entering the irradiation chamber during operation, resulting in a worker receiving a near-lethal dose of radiation.

ca. December 1991
One of four cold fusion cells in a Menlo Park, CA, laboratory exploded while being moved; electrochemist Andrew Riley was killed and three others were injured. The other three cells were buried on site, leading to rumors that a nuclear reaction had taken place. A report concluded that it was a chemical explosion; a mixture of oxygen and deuterium produced by electrolysis ignited when a catalyst was exposed. The Electric Power Research Institute, which spent $2 million on the SRI cold fusion research, suspended support for the work pending the outcome of an investigation.

Radioactive tritium and strontium (the latter at up to 70 times the drinking water standard) were found to have contaminated groundwater around Brookhaven National Laboratory in Upton, NY during a routing shutdown. The details are covered in a report by the U.S. Nuclear Regulatory Commission. The facility was cited by the U.S. Department of Energy for multiple failures to comply with nuclear safety requirements on numerous subsequent occasions, including 7 June 1996, 19 December 1997 and 19 April 1999

June 2013
A report was issued by the U.S. Department of Defense's Defense Threat Reduction Agency detailing numerous problems that occurred at a nuclear plant used to generate electricity at the McMurdo, Antarctica base. A total of 438 malfunctions were documented, including four reports of "Release of any radioactivity to the environment in excess of Title 10, Code of Federal Regulations, Part 20", 11 reports of "se of radiation or radioactivity levels within the plant by more than a factor of 3 from normal operating conditions" and 123 reports of "Exposure to personnel greater than 0.350 rem (3.5 mSv) in seven consecutive days".

Power Plants

3 January 1961
The world's first nuclear-related fatalities occurred following a reactor explosion at the National Reactor Testing Station in Idaho Falls, Idaho. Three technicians, were killed, with radioactivity "largely confined" (according to John A. McCone, Director of the Atomic Energy Commission) to the reactor building. The men were killed as they moved fuel rods in a "routine" preparation for the reactor start-up. One technician was blown to the ceiling of the containment dome and impaled on a control rod. His body remained there until it was taken down six days later. The men were so heavily exposed to radiation that their hands had to be buried separately with other radioactive waste, and their bodies were interred in lead coffins. Another incident at this station three weeks later (on 25 January) resulted in a release of radiation into the atmosphere. Photos documenting this accident are posted to www.radiationworks.com/photos/sl1reactor1.htm.

24 July 1964
Robert Peabody, 37, died at the United Nuclear Corp. fuel facility in Charlestown, Rhode Island, when liquid uranium he was pouring went critical, starting a reaction that exposed him to a lethal dose of radiation.

19 November 1971
The water storage space at the Northern States Power Company's reactor in Monticello, Minnesota filled to capacity and spilled over, dumping about 50,000 gallons of radioactive waste water into the Mississippi River. Some was taken into the St. Paul water system.

March 1972
Senator Mike Gravel of Alaska submitted to the Congressional Record facts surrounding a routine check in a nuclear power plant which indicated abnormal radioactivity in the building's water system. Radioactivity was confirmed in the plant drinking fountain. Apparently there was an inappropriate cross-connection between a 3,000 gallon radioactive tank and the water system.

27 July 1972
Two workers at the Surry Unit 2 facility in Virginia were fatally scalded after a routine valve adjustment led to a steam release in a gap in a vent line. [See also 9 December 1986]

28 May 1974
The Atomic Energy Commission reported that 861 "abnormal events" had occurred in 1973 in the nation's 42 operative nuclear power plants. Twelve involved the release of radioactivity "above permissible levels."

22 March 1975
A technician checking for air leaks with a lighted candle caused $100 million in damage when insulation caught fire at the Browns Ferry reactor near Decatur, Alabama. The fire burned out electrical controls, lowering the cooling water to dangerous levels, before the plant could be shut down.

28 March 1979
A major accident at the Three Mile Island nuclear plant near Middletown, Pennsylvania. At 4:00 a.m. a series of human and mechanical failures nearly triggered a nuclear disaster. By 8:00 a.m., after cooling water was lost and temperatures soared above 5,000 degrees, the top portion of the reactor's 150-ton core melted. Contaminated coolant water escaped into a nearby building, releasing radioactive gasses, leading as many as 200,000 people to flee the region. Despite claims by the nuclear industry that "no one died at Three Mile Island," a study by Dr. Ernest J. Sternglass, professor of radiation physics at the University of Pittsburgh, showed that the accident led to a minimum of 430 infant deaths.

The Critical Mass Energy Project of Public Citizen, Inc. reported that there were 4,060 mishaps and 140 serious events at nuclear power plants in 1981, up from 3,804 mishaps and 104 serious events the previous year.

11 February 1981
An Auxiliary Unit Operator, working his first day on the new job without proper training, inadvertently opened a valve which led to the contamination of eight men by 110,000 gallons of radioactive coolant sprayed into the containment building of the Tennessee Valley Authority's Sequoyah I plant in Tennessee.

July 1981
A flood of low-level radioactive wastewater in the sub-basement at Nine Mile Point's Unit 1 (in New York state) caused approximately 150 55-gallon drums of high-level waste to overturn, some of which released their highly radioactive contents. Some 50,000 gallons of low-level radioactive water were subsequently dumped into Lake Ontario to make room for the cleanup. The discharge was reported to the Nuclear Regulatory Commission, but the sub-basement contamination was not. A report leaked to the press 8 years later resulted in a study which found that high levels of radiation persisted in the still flooded facility.

The Critical Mass Energy Project of Public Citizen, Inc. reported that 84,322 power plant workers were exposed to radiation in 1982, up from 82,183 the previous year.

25 January 1982
A steam generator pipe broke at the Rochester Gas & Electric Company's Ginna plant near Rochester, New York. Fifteen thousand gallons of radioactive coolant spilled onto the plant floor, and small amounts of radioactive steam escaped into the air.

15-16 January 1983
Nearly 208,000 gallons of water with low-level radioactive contamination was accidentally dumped into the Tennesee River at the Browns Ferry power plant.

25 February 1983
A catastrophe at the Salem 1 reactor in New Jersey was averted by just 90 seconds when the plant was shut down manually, following the failure of automatic shutdown systems to act properly. The same automatic systems had failed to respond in an incident three days before, and other problems plagued this plant as well, such as a 3,000 gallon leak of radioactive water in June 1981 at the Salem 2 reactor, a 23,000 gallon leak of "mildly" radioactive water (which splashed onto 16 workers) in February 1982, and radioactive gas leaks in March 1981 and September 1982 from Salem 1.

9 December 1986
A feedwater pipe ruptured at the Surry Unit 2 facility in Virginia, causing 8 workers to be scalded by a release of hot water and steam. Four of the workers later died from their injuries. In addition, water from the sprinkler systems caused a malfunction of the security system, preventing personnel from entering the facility. This was the second time that an incident at the Surry 2 unit resulted in fatal injuries due to scalding [see also 27 July 1972].

It was reported that there were 2,810 accidents in U.S. commercial nuclear power plants in 1987, down slightly from the 2,836 accidents reported in 1986, according to a report issued by the Critical Mass Energy Project of Public Citizen, Inc.

28 May 1993
The Nuclear Regulatory Commission released a warning to the operators of 34 nuclear reactors around the country that the instruments used to measure levels of water in the reactor could give false readings during routine shutdowns and fail to detect important leaks. The problem was first bought to light by an engineer at Northeast Utilities in Connecticut who had been harassed for raising safety questions. The flawed instruments at boiling-water reactors designed by General Electric utilize pipes which were prone to being blocked by gas bubbles; a failure to detect falling water levels could have resulted, potentially leading to a meltdown.

15 February 2000
New York's Indian Point II power plant vented a small amount of radioactive steam when a an aging steam generator ruptured. The Nuclear Regulatory Commission initially reported that no radioactive material was released, but later changed their report to say that there was a leak, but not of a sufficient amount to threaten public safety.

6 March 2002
Workers discovered a foot-long cavity eaten into the reactor vessel head at the Davis-Besse nuclear plant in Ohio. Borated water had corroded the metal to a 3/16 inch stainless steel liner which held back over 80,000 gallons of highly pressurized radioactive water. In April 2005 the Nuclear Regulatory Commission proposed fining plant owner First Energy 5.4 million dollars for their failure to uncover the problem sooner (similar problems plaguing other plants were already known within the industry), and also proposed banning System Engineer Andrew Siemaszko from working in the industry for five years due to his falsifying reactor vessel logs. As of this writing the fine and suspension were under appeal.

November 2005
High tritium levels, the result of leaking pipes, were discovered to have contaminated groundwater immediately adjacent to the Braidwood Generating Station in Braceville, Illinois.

7 January 2010
Officials at the Vermont Yankee Nuclear Power station in Vernon, Vermont notified the Vermont Department of Health that samples taken from a monitoring well in November 2009 contained radioactive tritium at levels 37 times the federal limit. The source of the leak was traced the following month to a pair of badly corroded and leaking steam pipes, and a clogged floor drain; a second leak was discovered and repaired four months later.

May 2011
The U.S. Nuclear Regulatory Commission commenced meetings to discuss problems at a nuclear reactor in Braidwood, Illinois. Findings included the release of six million gallons of water containing radioactive tritium into the local aquifer, improper wiring of an alarm system intended to warn plant workers of problems, and a flaw in the plant's backup water supply.

June 2011
An AP investigation revealed that three quarters of all nuclear plants in the U.S. were found to be leaking radioactive tritium. Over half the plants studied had concentrations exceeding the federal drinking water standard, and while none had reached public drinking supplies, leaks at three plants had contaminated the drinking wells of nearby homes.

31 January 2012
A crack in a tube at the San Onofre plant in California led to a minor leak of radioactive steam. Approximately 8.7% of the tubes in a replacement steam generator experienced damage due to a design flaw. The plant was permanently shuttered the following year.

22 November 2022
A broken pipe between two buildings at Xcel Energy’s Monticello, Minnesota nuclear power plant resulted in a leak of 400,000 gallons of tritium-tainted radioactive water. The leak, which resulted in groundwater contamination, was reportedly contained on-site.

Missiles, Bombs and Bombers

13 February 1950
A B-36 en route from Alaska to Carswell Air Force Base in Fort Worth, Texas, developed serious mechanical difficulties, complicated by severe icing conditions. The crew headed out over the Pacific Ocean and dropped its nuclear weapon from 8,000 feet off the coast of British Columbia. The weapon's high-explosive material detonated on impact, and the crew parachuted to safety after bailing out over Princess Royal Island.

11 April 1950
A B-29 flying from Kirtland Air Force Base crashed into a mountain near Manzano Base in Albuquerque, New Mexico, killing 12 crewmembers aboard and 7 on the ground. A nuclear weapon onboard the aircraft was destroyed in the crash. See www.check-six.com/Crash_Sites/Travis_B-29_crash_site.htm for additional details.

5 August 1950
A B-29 carrying Mark IV nuclear bombs crashed on takeoff from Fairfield-Suisun Air Force Base in California, killing 12 crewmembers and passengers aboard. The resultant fire led to an explosion of the conventional explosives, killing another six rescue workers on the ground. The base was later re-named for General Robert Travis, the Commander (and a casualty) of the B-29.

10 November 1950
A B-50 en route to Davis-Monthan Air Force Base in Tucson, Arizona, was forced to jettison a nuclear weapon over the St. Lawrence River near St. Alexandre-de-Kamouraska, Canada.

10 March 1956
A B-47 with two capsules of nuclear weapons fuel aboard disappeared over the Mediterranean Sea after flying out of MacDill Air Force Base in Tampa, Florida. An exhaustive search failed to locate the aircraft, its crew, or the nuclear fuel capsules.

27 July 1956
A U.S. B-47 practicing a touch-and-go landing at Lakenheath Royal Air Force Station near Cambridge, England went out of control and smashed into a storage igloo housing three Mark 6 nuclear bombs, each of which had about 8,000 pounds of TNT in its trigger mechanism. No crewmen were killed, and fire fighters were able to extinguish the blazing jet fuel before it ignited the TNT.

22 May 1957
A 10 megaton hydrogen bomb was accidentally dropped from a B-36 bomber in an uninhabited area near Albuquerque, New Mexico owned by the University of New Mexico. The conventional explosives detonated, creating a 12 foot deep crater 25 feet across (in which some radiation was detected) and ejecting fragments and debris up to a mile from site.

28 July 1957
A C-124 Globemaster transporting three nuclear weapons and a nuclear capsule from Dover Air Force Base in Delaware to Europe experienced loss of power in two engines. The crew jettisoned two of the weapons somewhere east of Rehobeth, Del., and Cape May/Wildwood, New Jersey. A search for the weapons was unsuccessful and it is a fair assumption that they still lie at the bottom of the ocean.

11 October 1957
A B-47 carrying a single nuclear weapon crashed shortly after takeoff from Homestead Air Force Base in Florida. The weapon was partially destroyed in the ensuing fire, but the nuclear core was recovered intact.

31 January 1958
A B-47 loaded with a nuclear weapon collapsed and caught fire on the runway at a U.S. Strategic Air Command base 90 miles northeast of Rabat, Morocco. The U.S. State Department denied the accidental explosion, reporting instead that "a practice evacuation" had occurred.

5 February 1958
A B-47 carrying a Mark 15, Mod 0, nuclear bomb on a simulated combat mission from Homestead Air Force Base in Florida collided with an F-86 near Savannah, Georgia. After three unsuccessful attempts to land at Hunter Air Force Base in Georgia, the B-47 crew jettisoned the nuclear bomb in the Atlantic Ocean off Savannah. The Air Force conducted a nine-week search of a 3-square-mile area in Wassaw Sound where the bomb was dropped, but declared on April 16 that the bomb was irretrievably lost. More details can be read in this Wikipedia article.

11 March 1958
A B-47 on its way from Hunter Air Force Base in Georgia to an overseas base accidentally dropped an unarmed nuclear weapon into the garden of Walter Gregg and his family in Mars Bluff, South Carolina. The conventional explosives detonated, destroying Gregg's house and injuring six family members. The blast resulted in the formation of a crater 50-70 feet wide and 25-30 feet deep. Five other houses and a church were also damaged; five months later the Air Force paid the Greggs $54,000 in compensation.

4 November 1958
A B-47 carrying a nuclear weapon caught fire and crashed during takeoff from Dyess Air Force Base in Abilene, Texas, killing one crew member. The conventional explosives detonated, leaving a crater 35 feet wide and six feet deep.

26 November 1958
A B-47 caught fire on the ground at Chennault Air Force Base in Lake Charles, Louisiana, destroying a nuclear weapon onboard, resulting in minor radioactive contamination of the immediate vicinity.

6 July 1959
A C-124 aircraft with a nuclear weapon aboard crashed on take-off at Barksdale Air Force Base in Louisiana, resulting in radioactive contamination of the immediate area.

15 October 1959
A B-52 bomber with two nuclear weapons aboard, and a KC-135 jet tanker, collided over Hardinsburg, Kentucky during a mid-air refueling shortly after departing Columbus Air Force Base in Mississippi. All four members of the tanker crew were killed, as were four of the eight members of the B-52 crew. The bomber subsequently crashed, and the nuclear weapons were recovered intact with minor burn damage to one.

7 June 1960
A BOMARC-A nuclear missile burst into flames after its fuel tank was ruptured by the explosion of a high pressure helium tank at McGuire Air Force Base in New Egypt, New Jersey. The missile melted, causing plutonium contamination at the facility and (due to runoff from firefighting water) in the ground water below.

3 December 1960
A Titan I missile exploded in its silo at Vandenberg Air Force Base in California due to an elevator malfunction. There were no injuries, but the facility was permanently destroyed.

21 January 1961
A B-52 bomber carrying one or more nuclear weapons disintegrated in midair following an engine fire and explosion approximately 10 miles north of Monticello, Utah, killing all five crewmembers.

24 January 1961
A B-52 bomber suffered structural failure and disintegrated in mid-air 12 miles north of Seymour Johnson Air Force Base in Goldsboro, NC, releasing two hydrogen bombs. Five crewmen parachuted to safety, while three others died when the aircraft exploded in mid-air. The bombs jettisoned as the plane descended, one parachuting to earth intact, the other plunging deep into waterlogged farmland. To this day, parts of the nuclear bomb remain embedded deep in the muck. The area is off-limits, and is tested regularly for radiation releases. More information can be found at the Broken Arrow: Goldsboro, NC site at www.ibiblio.org/bomb/.

14 March 1961
A B-52 on a training mission with two nuclear weapons aboard crashed in Yuba City, California following depressurization of the crew cabin. The crew bailed out at 10,000 feet altitude, but the commander stayed aboard to steer the stricken bomber away from populated areas until the craft descended to 4,000 feet.

November 1963
A B52 carrying two hydrogen bombs crashed into a hillside approximately 20 miles from Cumberland, Maryland during a snowstorm. One of the crewmembers was killed on impact; another died of injuries and exposure in the zero-degree weather. The bombs were recovered intact from the wreckage of the aircraft.

13 January 1964
A B-52D en route from Westover Air Force Base in Massachusetts to Turner Air Force Base in Georgia crashed 17 miles southwest of Cumberland, Maryland. Three of the five crewmembers were killed, and the two nuclear weapons aboard were recovered intact.

8 December 1964
A B-58 slid off an icy runway at Bunker Hill (now Grissom) Air Force Base in Peru, Indiana. The resulting fire consumed portions of five onboard nuclear weapons, leading to radioactive contamination of the surrounding area. Systems operator Roger Hall was killed in an attempt to eject from the stricken aircraft, and two other crewmembers experienced non life-threatening burns.

December 1964
An electrical fault led to the firing of a retro-rocket aboard a Minuteman missile at Ellsworth Air Force Base in South Dakota. The onboard nuclear device was jettisoned from the missile, landing at the bottom of the missile silo.

9 August 1965
A welder at a Titan missile silo outside Searcy, Arkansas, accidentally hit a hydraulic line, leading to a fire and power outage that resulted in the deaths of 53 workers. w11 October 1965
A fire at a refueling facility at Wright-Patterson Air Force Base in Ohio spread to a C-124 cargo plane with nuclear weapons aboard, resulting in radioactive contamination to the aircraft, its cargo, and the clothing of explosive ordnance disposal and firefighting personnel.

5 December 1965
An A-4E aircraft accidentally rolled off the USS Toconderoga, with the loss of pilot Lt. Douglas M. Webster and one nuclear weapon. The incident, which occurred in the Pacific Ocean approximately 200 miles east of Okinawa, was not reported in detail by the Department of Defense until 1981.

17 January 1966
A B-52 collided with an Air Force KC-135 jet tanker while refueling over the coast of Spain, killing eight of the eleven crew members and igniting the KC-135's 40,000 gallons of jet fuel. Two hydrogen bombs ruptured, scattering radioactive particles over the fields of Palomares; a third landed intact near the village of Palomares; the fourth was lost at sea 12 miles off the coast of Palomares and required a search by thousands of men working for three months to recover it. Approximately 1,400 tons of radioactive soil and vegetation were removed to the U.S. for burial at a nuclear waste dump in Aiken, S.C. The U.S. eventually settled claims by 522 Palomares residents at a cost of $600,000, and gave the town the gift of a $200,000 desalinizing plant.

22 January 1968
A B-52 crashed 7 miles south of Thule Air Force Base in Greenland, scattering the radioactive fragments of three hydrogen bombs over the terrain and dropping one bomb into the sea after a fire broke out in the navigator's compartment. Contaminated ice and airplane debris were sent back to the U.S., with the bomb fragments going back to the manufacturer in Amarillo, Texas. The incident outraged the people of Denmark (which owned Greenland at the time, and which prohibits nuclear weapons over its territory) and led to massive anti-U.S. demonstrations.

Spring 1968
An unknown nuclear accident occurred involving a U.S. military craft at sea in or over the Atlantic Ocean. As of 1980 the incident remained classified.

19 September 1980
An Air Force repairman doing routine maintenance in a Titan II ICBM silo in Damascus, Arkansas 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 areas were evacuated. Eight and a half hours later, the fuel vapors ignited, causing an explosion which killed an Air Force specialist and injured 21 others. The explosion also blew off the 740-ton reinforced concrete-and-steel silo door and catapulted the warhead 600 feet into the air. The silo has since been filled in with gravel, and operations were transferred to a similar installation at Rock, Kansas. The episode is described in detail in Eric Schlosser's Command and Control: Nuclear Weapons, The Damascus Accident, and the Illusion of Safety.

2 November 1981
A fully-armed Poseidon missile was accidentally dropped 17 feet from a crane in Scotland during a transfer operation between a U.S. submarine and its mother ship.

Submarines and Ships

Some of the following incidents involve the discharge of radioactive coolant water by ships and submarines. While water from the primary coolant system stays radioactive for only a few seconds, it picks up bits of cobalt, chromium and other elements (from rusting pipes and the reactor) which remain radioactive for years. In realization of this fact, the U.S. Navy has curtailed its previously frequent practice of dumping coolant at sea.

18 April 1959
An experimental sodium-cooled reactor utilized aboard the USS Seawolf, the U.S.'s second nuclear submarine, was scuttled in 9,000 feet of water off the Delaware/Maryland coast in a stainless steel containment vessel. The reactor was plagued by persistent leaks in its steam system (caused by the corrosive nature of the sodium) and was later replaced with a more conventional model. The reactor is estimated to have contained 33,000 curies of radioactivity and is likely the largest single radioactive object ever dumped deliberately into the ocean. Subsequent attempts to locate the reactor proved to be futile.

October 1959
One man was killed and another three were seriously burned in the explosion and fire of a prototype reactor for the USS Triton at the Navy's training center in West Milton, New York. The Navy stated, "The explosion...was completely unrelated to the reactor or any of its principal auxiliary systems," but sources familiar with the operation claim that the high-pressure air flask which exploded was utilized to operate a critical back-up system in the event of a reactor emergency.

The USS Theodore Roosvelt was contaminated when radioactive waste from its demineralization system, blew back onton the ship after an attempt to dispose of the material at sea. This happened on other occasions as well with other ships (for example, the USS Guardfish in 1975).

10 April 1963
The nuclear submarine Thresher imploded during a test dive east of Boston, killing all 129 men aboard.

5 December 1965
{This write-up is drawn from the US Nuclear Weapons Accidents page formerly located at www.cdi.org/Issues/NukeAccidents/accidents.htm}

An A-4E Skyhawk strike aircraft carrying a nuclear weapon rolled off an elevator on the U.S. aircraft carrier Ticonderoga and fell into the sea. Because the bomb was lost at a depth of approximately 16,000 feet, Pentagon officials feared that intense water pressure could have caused the B-43 hydrogen bomb to explode. It is still unknown whether an explosion did occur. The pilot, aircraft, and weapon were lost.

The Pentagon claimed that the bomb was lost "500 miles away from land." However, it was later revealed that the aircraft and nuclear weapon sank only miles from the Japanese island chain of Ryukyu. Several factors contributed to the Pentagon's secretiveness. The USS Ticonderoga was returning from a mission off North Vietnam; confirming that the carrier had nuclear weapons aboard would document their introduction into the Vietnam War. Furthermore, Japan's anti-nuclear law prohibited the introduction of atomic weapons into its territory, and U.S. military bases in Japan are not exempt from this law. Thus, confirming that the USS Ticonderoga carried nuclear weapons would signify U.S. violation of its military agreements with Japan. The carrier was headed to Yokosuka, Japan, and disclosure of the accident in the mid-1980s caused a strain in U.S.-Japanese relations.

Radioactive coolant water may have been released by the USS Swordfish, which was moored at the time in Sasebo Harbor in Japan. According to one source, the incident was alleged by activists but a nearby Japanese government vessel failed to detect any such radiation leak. The purported incident was protested bitterly by the Japanese, with Premier Eisaku Sate warning that U.S. nuclear ships would no longer be allowed to call at Japanese ports unless their safety could be guaranteed.

22 May 1968
The U.S.S. Scorpion, a nuclear-powered attack submarine carrying two Mark 45 ASTOR torpedoes with nuclear warheads, sank mysteriously on this day. It was eventually photographed lying on the bottom of the ocean, where all ninety-nine of its crew were lost. Details of the accident remained classified until November 1993, when a Navy report detailing the incident was made public. The report suggested that a malfunction in one of Scorpion's torpedoes could have caused the sinking, but evidence from subsequent dives to the location suggest that this was not the culprit.

14 January 1969
A series of explosions aboard the nuclear aircraft carrier Enterprise left 17 dead and 85 injured.

16 May 1969
The U.S.S. Guitarro, a $50 million nuclear submarine undergoing final fitting in San Francisco Bay, sank to the bottom as water poured into a forward compartment. A House Armed Services subcommittee later found the Navy guilty of "inexcusable carelessness" in connection with the event.

12 December 1971
Five hundred gallons of radioactive coolant water spilled into the Thames River near New London, Connecticut as it was being transferred from the submarine Dace to the sub tender Fulton.

October-November 1975
The USS Proteus, a disabled submarine tender, discharged significant amounts of radioactive coolant water into Guam's Apra Harbor. A geiger counter check of the harbor water near two public beaches measured 100 millirems/hour, fifty times the allowable dose.

22 May 1978
Up to 500 gallons of radioactive water was released when a valve was mistakenly opened aboard the USS Puffer near Puget Sound in Washington.

November 1992
Due to a valve failure, the nuclear-powered USS Long Beach leaked 109 gallons of radioactive cooling water over a 44-day period while docked at San Diego Naval Station. An additional 50 gallons had leaked out there the previous April and May. The San Diego Union reported that coolant had also been released at Pearl Harbor (Hawaii) and Indian Island (Washington). U.S. Navy officials insist that the level of radiation posed no threat, and that a "very small amount of valve leakage that is unavoidable and occurs on all ships is well understood, controlled and accounted for."

Nuclear Bomb Tests and Testing Facilities - Other

26 April 1953
Radioactive rain, the result of above-ground nuclear tests, fell on Troy, New York.

5 September 1961
President Kennedy ordered the resumption of nuclear testing, "underground, with no fallout."

10 December 1961
Clouds of radioactive steam escaped from an underground nuclear test, closing several New Mexico highways.

4 June 1962 The Bluegill nuclear test, designed to detonate a nuclear device in the atmosphere, was aborted 10 minutes after launch when the missile tracking system failed prior to nuclear detonation. The nuclear device was lost at sea.

20 June 1962
A failure of the Starfish nuclear test, designed to detonate a nuclear device in space, caused radioactive debris to be scattered across Johnston Island in the Pacific Ocean.

July 1962
Another missile test on Johnston Island (involving the same Thor rocket used on 20 June 1962) misfired on the launchpad. The subsequent destruction of the missile resulted in destruction of the launch pad and accompanying plutonium contamination.

15 October 1962
Another failed missile test (approximately 90 seconds after launch) resulted in further plutonium contamination of Johnston Island (see previous two entries).

9 December 1968
Clouds of radioactive steam from a nuclear test in Nevada broke through the ground, releasing fallout and violating the Limited Nuclear Test Ban Treaty signed 5 years earlier.

18 December 1970
An underground nuclear test in Nevada (code-named "Baneberry") resulted in a release of radioactive steam 8,000 feet in the air over Wyoming.

15 July 1999
A spokesperson for President Clinton announced that thousands of contract workers at U.S. nuclear weapons facilities, exposed to toxic and radioactive substances during the previous 50 years, could seek federal compensation for related illnesses.

Processing, Storage, Shipping and Disposal

From 1946 to 1970 approximately 90,000 cannisters of radioactive waste were jettisoned in 50 ocean dumps up and down the East and West coasts of the U.S., including prime fishing areas, as part of the early nuclear waste disposal program from the military's atomic weapons program. The waste also included contaminated tools, chemicals, and laboratory glassware from weapons laboratories, and commercial/medical facilities

11 September 1957
A fire at the Rocky Flats Nuclear Weapons Plant near Denver, Colorato led to a serious release of plutonium dust and smoke into the atmosphere. Another serious fire occured at the same plant in 1969 {see entry}.

December 1962
A summary report was presented at an Atomic Energy Commission symposium in Germantown, Maryland, listing 47 accidents involving shipment of nuclear materials to that date, 17 of which were considered "serious."

13 November 1963
123,000 pounds of high explosives (components of obsolete nuclear weapons being disassembled) detonated at an Atomic Energy Commission storage facility at Medina Base, Texas. Three employees were injured, and minor radioactive contamination of the facility occurred.

11 May 1969
A plutonium fire broke out in Building 776 at the Atomic Energy Commission's Rocky Flats Nuclear Weapons Plant. Plutonium was released into the atmosphere and tracked out of the building on the boots of firefighters, and several buildings at the factory were so badly contaminated that they had to be dismantled.

After experimenting with disposal of radioactive waste in salt, the Atomic Energy Commission announced that "Project Salt Vault" would solve the waste problem. But when 180,000 gallons of contaminated water was pumped into a borehole; it promptly and unexpectedly disappeared. The project was abandoned two years later.

The West Valley, NY fuel reprocessing plant was closed after 6 years in operation, leaving 600,000 gallons of high-level wastes buried in leaking tanks. The site caused measurable contamination of Lakes Ontario and Erie.

December 1972
A major fire and two explosions occurred at a Pauling, New York plutonium fabrication plant. An undetermined amount of radioactive plutonium was scattered inside and outside the plant, resulting in its permanent shutdown.

The Critical Mass Energy Project (part of Ralph Nader's Public Citizen, Inc.) tabulated 122 accidents involving the transport of nuclear material in 1979, including 17 involving radioactive contamination.

16 July 1979
In the largest single release of radiation in U.S. history, a dam holding radioactive uranium mill tailings in Church Rock, New Mexico failed, sending an estimated 100 million gallons of radioactive liquids and 1,100 tons of solid waste as far as 50 miles downstream into neighboring Arizona.

August 1979
Highly enriched uranium was released from a top-secret nuclear fuel plant near Erwin, Tennessee. About 1,000 people were contaminated with up to 5 times as much radiation as would normally be received in a year. Between 1968 and 1983 the plant "lost" 234 pounds of highly enriched uranium, forcing the plant to be closed six times during that period.

January 1980
A 5.5 Richter earthquake at Lawrence Livermore National Laboratory, where large amounts of nuclear material are kept, caused a tritium leak.

21 September 1980
Two canisters containing radioactive materials fell off a truck on New Jersey's Route 17. The driver, en route from Pennsylvania to Toronto, did not notice the missing cargo until he reached Albany, New York.

The Department of Energy confirmed that 1,200 tons of mercury had been released over the years from the Y-12 Nuclear Weapons Components Plant at Oak Ridge, Tennessee, the U.S.'s earliest nuclear weapons production plant. In 1987, the DOE also reported that PCBs, heavy metals, and radioactive substances were all present in the groundwater beneath Y-12. Y-12 and the nearby K-25 and X-10 plants were found to have contaminated the atmosphere, soil and streams in the area.

December 1984
The Fernald Uranium Plant, a 1,050-acre uranium fuel production complex 20 miles northwest of Cincinnati, Ohio, was temporarily shut down after the Department of Energy disclosed that excessive amounts of radioactive materials had been released through ventilating systems. Subsequent reports revealed that 230 tons of radioactive material had leaked into the Greater Miami River valley during the previous thirty years, 39 tons of uranium dust had been released into the atmosphere, 83 tons had been discharged into surface water, and 5,500 tons of radioactive and other hazardous substances had been released into pits and swamps where they seeped into the groundwater. In addition, 337 tons of uranium hexafluoride was found to be missing, its whereabouts completely unknown. In 1988 nearby residents sued and were granted a $73 million settlement by the government. The plant was not permanently shut down until 1989. 1986
A truck carrying low-level radioactive material swerved to avoid a farm vehicle, went off a bridge on Route 84 in Idaho, and dumped part of its cargo in the Snake River. Officials reported the release of radioactivity.

6 January 1986
A container of highly toxic gas exploded at The Sequoyah Fuels Corp. uranium processing factory in Gore, Oklahoma, causing one worker to die (when his lungs were destroyed) and 130 others to seek medical treatment. In response, the Government kept the plant closed for more than a year and fined owners Kerr-McGee $310,000, citing poorly trained workers, poorly maintained equipment and a disregard for safety and the environment. [See also 24 November 1992.]

The National Research Council panel released a report listing 30 "significant unreported incidents" at the Savannah River production plants over the previous 30 years. As at Hanford, ground water contamination resulted from pushing production of radioactive materials past safe limits at this weapons complex. In January 1989, scientists discovered a fault running under the entire site through which contaminants reached the underground aquifer, a major source of drinking water for the southeast. Turtles in nearby ponds were found to contain radioactive strontium of up to 1,000 times the normal background level.

6 June 1988
Radiation Sterilizers, Incorporated reported that a leak of Cesium-137 had occurred at their Decatur, Georgia facility. Seventy thousand medical supply containers and milk cartons were recalled as they had been exposed to radiation. Ten employees were also exposed, three of whom "had enough on them that they contaminated other surfaces" including materials in their homes and cars, according to Jim Setser at the Georgia Department of Natural Resources.

October 1988
The Rocky Flats, Colorado plutonium bomb manufacturing site was partially closed after two employees and a Department of Energy inspector inhaled radioactive particles. Subsequent investigations revealed safety violations (including uncalibrated monitors and insufficient fire-response equipment) and leaching of radioactive contaminants into the local groundwater.

24 November 1992
The Sequoyah Fuels Corp. uranium processing factory in Gore, Oklahoma closed after repeated citations by the Government for violations of nuclear safety and environmental rules. It's record during 22 years of operation included an accident in 1986 that killed one worker and injured dozens of others and the contamination of the Arkansas River and groundwater. The Sequoyah Fuels plant, one of two privately-owned American factories that fabricated fuel rods and armor-piercing bullet shells, had been shut down a week before by the Nuclear Regulatory Commission when an accident resulted in the release of toxic gas. Thirty-four people sought medical attention as a result of the accident. The plant had also been shut down the year before when unusually high concentrations of uranium were detected in water in a nearby construction pit. [Also see 6 January 1986 for details of an additional incident.] A Government investigation revealed that the company had known for years that uranium was leaking into the ground at levels 35,000 times higher than Federal law allows; Carol Couch, the plant's environmental manager, was cited by the Government for obstructing the investigation and knowingly giving Federal agents false information.

31 March 1994
Fire at a nuclear research facility on Long Island, New York resulted in the nuclear contamination of three fire fighters, three reactor operators, and one technician. Measurable amounts of radioactive substances were released into the immediate environment.

8 August 1999
The Washington Post reported that thousands of workers were unwittingly exposed to plutonium and other highly radioactive metals over a 23-year period (beginning in the mid-1950's) at the Department of Energy's Paducah Gaseous Diffusion Plant in Kentucky. Workers, told they were handling Uranium (rather than the far more toxic plutonium), inhaled radioactive dust while processing the materials as part of a government experiment to recycle used nuclear reactor fuel.

June 2000
U.S. Senator Mike DeWine (R-OH) led a field senate hearing regarding workers exposed to hazardous materials while working in the nation's atomic plants. At the hearing, which revealed information about potential on and off-site contamination at the Portsmouth Gaseous Diffusion Plant in Piketon, Ohio, DeWine noted, "We know that as a result of Cold War efforts, the government, yes, our federal government, allowed thousands of workers at its facilities across the country to be exposed to poisonous materials, such as beryllium dust, plutonium, and silicon, without adequate protection." Testimony also indicated that the Piketon plant altered workers' radiation dose readings and worked closely with medical professionals to fight worker's compensation claims.

5 February 2014
A dump truck caught fire at the Waste Isolation Pilot Plant outside Carlsbad, New Mexico (a more serious accident would occur 9 days later - see following entry). The event is details in the official report from the U.S. Department of Energy.

14 February 2014
A 55-gallon drum of radioactive waste burst open at the Waste Isolation Pilot Plant outside Carlsbad, New Mexico, leading to internal radiological contamination of 22 employees and forcing a temporary shutdown of the facility. The incident occurred just 9 days after an accidental underground fire at the facility (see previous entry). The cause was determined to be a switch from from using clay kitty litter (a standard usage in the industry) to organic kitty litter, whose organic content interacted with the nuclear waste. More than 500 additional drums packed with the wrong type of litter were sealed in heavier containers to prevent their bursting. Numerous other safety issues were cited in the U.S. Department of Energy's official reports (Phase 1 and Phase 2) on the accident.

October 2022
High levels of radiation were discovered in classrooms, the playground and elsewhere at Jana Elementary School in Florissant, Missouri stemming from a World War II-era nuclear weapons production facility in nearby woods adjacent to Coldwater Creek. The U.S. Environmental Protection Agency had delcared Coldwater Creek a superfund site in 1989, with remediation efforts expected to continue until 2038.

Hanford Site

The Hanford site (referred to at various times as Hanford Project, Hanford Works, Hanford Engineer Works and Hanford Nuclear Reservation) is a former nuclear production site in southwestern Washington state. The site, in the process of being decommissioned (it is the nation's most contaminated nuclear site), has been the scene of numerous serious incidents over the past few decades, many involving releases of radioactivity into the adjacent soil, air, and the nearby Columbia River. An excellent summary in the IEEE Spectrum Magazine notes that cleanup efforts at Hanford are expected to "cost as much as $550 billion and last 60 years."

30 August 1976
A chemical explosion at Hanford resulted in injury to one worker, including contamination with radioactive Americium 241 so severe that an onsite alpha survey meter registered off-scale measurements.

After almost 40 years of cover-ups, the U.S. Government released 19,000 pages of previously classified documents which revealed that the Hanford site was responsible for the release of significant amounts of radioactive materials into the atmosphere and the adjacent Columbia River. Between 1944 and 1966, the eight reactors, a source of plutonium production for atomic weapons, discharged billions of gallons of liquids and billions of cubic meters of gases containing plutonium and other radioactive contaminants into the Columbia River, and the soil and air of the Columbia Basin. Although detrimental effects were noticed as early as 1948, all reports critical of the facilities remained classified. By the summer of 1987, the cost of cleaning up Hanford was estimated to be $48.5 billion.

The Technical Steering Panel of the government-sponsored Hanford Environmental Dose Reconstruction Project released the following statistics in July 1990: Of the 270,000 people living in the affected area, most received low doses of radiation from Iodine, but about 13,500 received a total dose some 1,300 times the annual amount of airborne radiation considered safe for civilians by the Department of Energy. Approximately 1,200 children received doses far in excess of this number, and many more received additional doses from contaminants other than Iodine.

Recurring problems at the site have continued; for example, on 5 November 2010 The Tri-City Herald reported on radioactive rabbits at the site straying "close enough to the site's boundaries to potentially come in contact with the public", prompting Washington State Department of Health workers to conduct a survey of contaminated droppings. In addition, Washington Closure Hanford, a contractor cleaning up part of Hanford, has erected fences, removed vegetation, installed gravel and steel plates, and scented the perimeter with fox urine to deter contaminated animals from burrowing under border fences.

May 1997
A 40 gallon tank of toxic chemicals (stored illegally at Handord) exploded, causing the release of 20,000-30,000 gallons of plutonium-contaminated water. A cover-up ensued, involving the contractors doing clean-up and the Department of Energy, who denied the release of radioactive materials. They also told eight plant workers that tests indicated that they hadn't been exposed to plutonium even though no such tests actually were conducted (later testing revealed that in fact they had not been exposed). Fluor Daniel Hanford Inc., operator of the Hanford Site, was cited for violations of the Department of Energy's nuclear safety rules and fined $140,625. Violations associated with the explosion 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. Other violations cited by the DOE included a number of events between November 1996 and June 1997 involving Fluor Daniel Hanford's failure to assure adherence to PFP "criticality" safety procedures. ("Criticality" features are defined as those features used "to assure safe handling of fissile materials and prevention of...an unplanned and uncontrolled chain reaction that can release large amounts of radiation.")

July 2000
Wildfires in the vicinity of the Hanford site hit the highly radioactive "B/C" waste disposal trenches, raising airborne plutonium radiation levels in the nearby cities of Pasco and Richland to 1,000 above normal. Wildfires also threatened the Los Alamos National Laboratory in New Mexico and the DOE's Idaho National Engineering and Environmental Laboratory. In the latter case, the fires closely approached large amounts of stored radioactive waste and forced the evacuation of 1,800 workers.

9 May 2013
Scientific American reported that 60 of 177 onsite underground tanks were found to be leaking. Controversy surrounding the project, run by contractor Bechtel National, Inc. led to the resignment of Chief project engineer Gary Brunson, while whistleblower complaints (alleging that safety concerns were suppressed by Bechtel) were filed by Nuclear and Environmental Safety Manager Donna Busche and former Deputy Chief Process Engineer Walter Tamosaitis.

9 May 2017
A portion of a tunnel used to store highly radioactive chemical waste and irradiated equipment collapsed, resulting in temporary evacuation of the site.

8 June 2017
At least 11 workers tested positive for internal exposure to plutonium following demolition activities, and radioactive particles were found well beyond the demolition zones where they were supposed to be contained. Department of Energy officials initially claimed that "workers were not at risk", but investigative journalism revealed internal memos from the contractor detailing the exposure. An evaluation report released by contractor CH2M Hill Plateau Remediation Co. in December 2017 identified failure of onsite air monitors and incorrect use of a "fixative" to contain radiation as contributors to the contamination.

home pageal's home page