Marie Curie (1867–1934) was a Polish-French physicist and chemist. She was a pioneer in the early field of radioactivity, later becoming the first two-time Nobel laureate and the only person with Nobel Prizes in physics and chemistry. Her death in 1934 was from aplastic anemia, almost certainly due to massive exposure to radiation in her work, much of which was carried out in a shed with no proper safety measures being taken, as the damaging effects of hard radiation were not generally understood at that time. She was known to carry test tubes full of radioactive isotopes in her pocket, and to store them in her desk drawer, resulting in massive exposure to radiation. She was known to remark on the pretty blue-green light the metals gave off in the dark.
Uranium was used in Italy and Greece in ancient times to color glass, dishes and jugs in orange, causing many people to be exposed to radiation as they ate and drank out of items painted with uranium.
Luminescent radium was used to paint watches and other items that glowed, but the dangers were largely unknown. The most famous incident is the Radium girls of Orange, New Jersey, but other towns including Ottawa, Illinois experienced contamination of homes and other structures.
Radium mining and manufacturing left a number of Denver, Colorado streets contaminated.
March, 1957– Employees of a Houston company licensed by the U.S. Atomic Energy Commission to encapsulate sources for radiographic cameras were exposed to 192Ir powder. This resulted in radiation burns to the two workers that were directly exposed. The 192Ir powder was then spread to several homes and cars in the community. The incident was reported in Look Magazine in 1961; investigations published by the Mayo Clinic that same year found few of the radiological injuries claimed in widespread press reports, but failed to assuage public fears that followed publicity of the accident.
September, 1957– Kyshtym accident near Chelyabinsk-40, USSR: about 7.4×1017Bq of radioactive products were ejected forming a kilometer-high radioactive cloud that left a radioactive trace of 15,000 km², as a result of the explosion of a waste tank.
21 January 1969 In Lucens, Switzerland, a pilot power reactor suffers a loss of coolant accident and partial core meltdown. Almost all of the radiation is contained inside the cavern containing the reactor. INES Level 4 Accident.
July 16, 1979 (34th anniversary of the Trinity test) – In Church Rock, New Mexico, the earth/clay dike of a uranium mill's settling/evaporating pond fails. The pond was past its planned and licensed life and had been filled two feet (60 cm) deeper than design, despite evident cracking. The incident drains about 100 million U.S. gallons (380,000 m³) of radioactive liquids and 1,100 short tons (1,000 metric tonnes) of solid wastes, which settle out up to 70 miles (100 km) down the Rio Puerco
September 29, 1979 - Tritium leak at American Atomics in Tucson, Arizona; at the public school across the street from the plant, $300,000 worth of food is found to be contaminated; chocolate cake had 56 nCi/L; by contrast, the EPA safety limit for drinking water is 20 nCi/L (740 Bq/L) based on consumption of 2 liters per day.
February 11, 1981 – A new worker inadvertently opened a valve and more than 100,000 U.S. gallons (380 m³) of slightly radioactive water leaked into the containment building of the Tennessee Valley Authority Sequoyah 1 nuclear power plant in rural Tennessee. Fourteen workers came into contact with the water.
March 1981 – More than 100 workers were exposed to doses of up to 155 millirad per day radiation during repairs of a nuclear power plant in Tsuruga, Japan, violating the company's limit of 100 millirads (1 mSv) per day. 
July 1981 – Lycoming, Nine Mile Point, New York. An overloaded wastewater tank was deliberately flushed into the waste building sub-basement, filling it to a depth of four feet. This caused some of the approximately one hundred fifty fifty-five-gallon drums that were stored there to overturn and spill their contents. Fifty thousand U.S. gallons (190 m³) of lesser-contaminated water was discharged into Lake Ontario. [NRC Region 1 augmented inspection team (AIT) inspection report# (50-220/89-90) of the use of the Radwaste building sub-basement as a long term liquid retention facility at Nine Mile Point unit 1.] October 2 1989
1982 – International Nutronics of Dover, New Jersey spilled an unknown quantity of radioactive cobalt solution used to treat gems for color, modify chemicals, and sterilize food and medical supplies. The solution spilled into the Dover sewer system and forced the closure of the plant. The Nuclear Regulatory Commission was only informed of the accident ten months later by a whistleblower. In 1986 International Nutronics was fined $35,000 and one of its top executives was sentenced to probation for failure to report the spill. 
1982 to present – radioactive steel scavenged from a nuclear reactor was melted into rebar and used in the construction of apartment buildings in northern Taiwan, mostly in Taipei, from 1982 through 1984. Over 2,000 apartment units and shops were suspected as having been built with the materials.  At least 10,000 people are known to have been exposed to long-term low-level irradiation as a result, with at least 40 deaths due to cancer. In 1985, the Taiwanese Atomic Energy Commission covered up the discovery of high levels of radiation in an apartment building by blaming a dentist operating an imaging machine. However, in the summer of 1992, a utility worker for the Taiwanese state-run electric utilily Taipower brought a Geiger counter to his apartment to learn more about the device, and discovered that his apartment was contaminated. Despite awareness of the problem, owners of some of the buildings known to be contaminated have continued to rent apartments out to tenants (in part because selling the units is illegal), and as of at least 2003 and likely to the present, no coordinated effort has been made to track down the remaining affected structures, and the Taiwan AEC has harrassed medical researchers looking into the consequences.
December 6, 1983 – Ciudad Juárez, Mexico, A local resident salvaged materials from a discarded radiation therapy machine carrying 6,000 pellets of 60Co. The dismantling and transport of the material led to severe contamination of his truck; when the truck was scrapped, it in turn contaminated another 5,000 metric tonnes of steel with an estimated 300 Ci (11 TBq) of activity. This material was sold for kitchen or restaurant table legs and building materials some of which was sent to the U.S. and Canada; the incident was discovered when a truck delivering contaminated building materials months later to the Los Alamos National Laboratory accidentally drove through a radiation monitoring station. Contamination was later measured on the roads that were used to transport the original damaged radiation source. In some cases pellets were actually found embedded in the roadway. In the state of Sinaloa, 109 houses were condemned due to contaminated building material. This incident prompted the Nuclear Regulatory Commission and Customs Service to install radiation detection equipment at all major border crossings. 
1985 to 1987, Therac-25 was a radiation therapy machine produced by Atomic Energy of Canada Limited. It was involved with at least six known accidents between 1985 and 1987, in which patients were given massive overdoses of radiation, which were in some cases on the order of hundreds of Grays. At least five patients died of the overdoses. These accidents highlighted the dangers of software control of safety-critical systems.
January 6, 1986 – At the Kerr-McGee nuclear fuel reprocessing plant in Gore, Oklahoma, a cylinder of UF6 burst after being improperly heated. One worker died of caustic chemical exposure; 30 were injured.
1986 – The NRC revoked 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 had been bypassed. A worker had received a near-lethal dose of radiation. RTI was cited 32 times. Violations also included throwing radioactive garbage out with the regular trash.
January 1987 – A Columbia University undergraduate steals radioactive 238U from an abandoned basement lab—where Enrico Fermi had conducted his early fission experiments, in fact. A USNRC investigation found no significant harm to person or property, though the student was expelled.
September 13, 1987 – In the Goiânia accident, scavengers broke open a radiation-therapy machine in an abandoned clinic of Goiânia, Brazil. They sold the kilocurie (40 TBq) 137Cs source as a glowing curiosity. Four hundred were contaminated, four died.
June 6, 1988 – Radiation Sterilizers in Decatur, Georgia, reported a leak of 137Cs at their facility. Seventy thousand medical supply containers and milk cartons were recalled. Ten employees were exposed, and three "had enough on them that they contaminated other surfaces," including their homes and cars.
5 February, 1989 Three workers were exposed to gamma rays from the 60Co source in a medical products irradiation plant in San Salvador, El Salvador. The most exposed person died while the other two lost limbs. This was a human error accident where a person made the wrong choice to enter the irradiation room.
June 24, 1990 – Soreq, Israel An operator at a commercial irradiation facility bypassed the safety systems on the JS6500 sterilizer to clear a jam in the product conveyor area. The one to two minute exposure resulted in a whole body dose estimated at 10 Gy or more. He died 36 days later despite extensive medical care. See Fool Irradiation  for a discussion of this type of event. 
October 26 1991 – Nesvizh, Belarus An operator at an atomic sterilization facility bypassed the safety systems to clear a jammed conveyor. Upon entering the irradiation chamber he was exposed to an estimated whole body dose of 11 Gy, with some portions of the body receiving upwards of 20 Gy. Prompt intensive medical care managed to keep him alive for 113 days after the accident.
April 6, 1993 – Tomsk, Russia At the Tomsk-7 Siberian Chemical Enterprise plutonium reprocessing facility, a pressure buildup led to an explosive mechanical failure in a 34 cubic meter stainless steel reaction vessel buried in a concrete bunker under building 201 of the radiochemical works. The vessel contained a mixture of concentrated nitric acid, uranium (8757 kg), plutonium (449 g) along with a mixture of radioactive and organic waste from a prior extraction cycle. The explosion dislodged the concrete lid of the bunker and blew a large hole in the roof of the building, releasing approximately 6 GBq of 239Pu and 30 TBq of various other radionuclides into the environment. The accident exposed 160 on-site workers and almost two thousand cleanup workers to total doses of up to 50 mSv (the threshold limit for radiation workers is 100 mSv per 5 years). The contamination plume extended 28 km NE of building 201, 20 km beyond the facility property. The small village of Georgievka (pop. 200) was at the end of the fallout plume, but no fatalities, illnesses or injuries were reported. 
August 31, 1994 – Commerce Township, Michigan David Hahn's experimental reactor was discovered in his mother's back yard. The unshielded reactor exposed his neighborhood to 1,000 times the normal levels of background radiation.
October 21, 1994 a large 137Cs source is stolen by scrap metal scavengers in Tammiku, Estonia.
May 1998 – Recycler Acerinox in Cádiz, Spain, unwittingly melts scrap metal containing radioactive sources; the radioactive cloud drifts all the way to Switzerland before being detected. (See Acerinox accident.)
1999 – A road near Mrima Hill, Kenya was rebuilt using local materials later found to be radioactive. Some workers were exposed to excessive radiation, and many residents of the area were tested for exposure. 2,975 tons[vague] of roadway material were to be dug up to eliminate the hazard. 
February 1, 2000 – The radiation source of a teletherapy unit was stolen from a parking lot in Samut Prakarn, Thailand and dismantled in a junkyard for scrap metal. Workers completely removed the 60Co source from the lead shielding, and became ill shortly thereafter. The radioactive nature of the metal and the resulting contamination was not discovered until 18 days later. Seven injuries and three deaths were a result of this incident. 
December 2000 – Three woodcutters in the nation of Georgia spent the night beside several "warm" canisters they found deep in the woods and were subsequently hospitalized with severe radiation burns. The canisters were found to contain concentrated 90Sr. The disposal team consisted of 25 men who were restricted to 40 seconds' worth of exposure each while transferring the canisters to lead-lined drums. The canisters are believed to have been intended for use as generators for remote lighthouses and navigational beacons, part of a Soviet plan dating back to 1983.
February 9, 2002 – Two workers were exposed to a small amount of radiation and suffered minor burns when a fire broke out at the Onagawa Nuclear Power Station in Miyagi Prefecture. The fire occurred in the basement of reactor #3 during a routine inspection when a spray can was punctured accidentally, igniting a sheet of plastic. 
March 11, 2002 – A 2.5 metric tonne 60Co gamma source was transported from Cookridge Hospital, Leeds, UK, to Sellafield with defective shielding. As the radiation escaped from the package downwards into the ground, it is not thought that this event caused any injury or disease in either a human or an animal. This event was treated in a serious manner because the defense in depth type of protection for the source had been eroded. If the container had been tipped over in a road crash then a strong beam of gamma rays would have been directed in a direction where it would be likely to irradiate humans. The company responsible for the transport of the source, AEA Technology plc, was fined £250,000 by a British court.
2003 – Cape of Navarin, Chukotka Autonomous Okrug, Russia. A radioisotope thermoelectric generator (RTG) located on the Arctic shore was discovered in a highly degraded state. The level of the exposition dose at the generator surface was as high as 15 R/h; in July 2004 a second inspection of the same RTG showed that gamma radiation emission had risen to 87 R/h and that 90Sr had begun to leak into the environment.  In November 2003, a completely dismantled RTG located on the Island of Yuzhny Goryachinsky in the Kola Bay was found. The generator's radioactive heat source was found on the ground near the shoreline in the northern part of the island. 
September 10 2004 – Yakutia, Russia. Two radioisotope thermoelectric generators were dropped 50 meters onto the tundra at Zemlya Bunge island during an airlift when the helicopter flew into heavy weather. According to the nuclear regulators, the impact compromised the RTGs' external radiation shielding. At a height of 10 meters above the impact site, the intensity of gamma radiation was measured at 4 mSv/hr. 
2005 – Dounreay, UK. In September, the site's cementation plant was closed when 266 liters of radioactive reprocessing residues were spilled inside containment. . In October, another of the site's reprocessing laboratories was closed down after nose-blow tests of eight workers tested positive for trace radioactivity. 
November 3, 2005 – Haddam, Connecticut, USA. The Connecticut Yankee Atomic Power Company reports that water containing quantities (below safe drinking water limits) of 137Cs, 60Co, 90Sr, and 3H leaked from a spent fuel pond. Independent measurements and review of the incident by the U.S. Nuclear Regulatory Commission are due to begin November 7, 2005. 
March 11, 2006 – at Fleurus, Belgium, an operator working for the company Sterigenics, at a medical equipment sterilization site, entered the irradiation room and remained there for 20 seconds. The room contained a source of 60Co which was not in the pool of water. Three weeks later, the worker suffered of symptoms typical of an irradiation (vomit, loss of hair, fatigue). One estimate that he was exposed to a dose of between 4.4 and 4.8 Gy due to a malfunction of the control-command hydraulic system maintaining the radioactive source in the pool. The operator spent over one month in a specialized hospital before going back home. Today he still shows after-effects (fatigue) that should attenuate in several months. To protect workers, the federal nuclear control agency AFCN and private auditors from AVN recommended Sterigenics to install a redundant system of security. It is an accident of level 4 on the INES scale.
March 16, 2006 – The State of Illinois sued Exelon Corporation for repeated leaks of tritium into water discharged around its Braidwood Nuclear Generating Station. Exelon states that despite the leaks it has operated within legal limits, but agreed to compensate landowners.   The tritium was produced during normal operation and, as fuel reactivity declines, is legally discharged with the borated water into the nearby river. However, some of this water leaked onto land. On March 20, the Nuclear Regulatory Commission announced it had formed a task force to examine tritium leaks , and a “white paper” was issued on June 30. 
May 5, 2006 – An accidental release of 131I gas at a nuclear power plant in Minnesota exposed approximately one hundred plant workers to low-level radiation. Most workers received 10 to 20 millirads (0.1-0.2 mSv), about the same as a dental X-ray. The workers were wearing protective gear at the time, and no radiation leaked outside the plant to the surrounding area. 
The late Lisa Norris died in 2006 after having been given an overdose of radiation as a result of human error during treatment for a brain tumor at Beatson Oncology Centre in Glasgow (Scotland).. The Scottish Executive have published an independent investigation of this case.. The intended treatment for Lisa Norris was 35 Gy to be delivered by a LINAC machine to the whole of the central nervous system to be delivered in twenty equal fractions of 1.75 Gy, which was to be followed by 19.8 Gy to be delivered to the tumor only (in eleven fractions of 1.8 Gy). In the first phase of the treatment a 58% overdose occurred, and the CNS of Lisa Norris suffered a dose of 55.5 Gy. The second phase of the treatment was abandoned on medical advice, after having lived for some time after the overdose Lisa Norris passed away.
International Nuclear Events Scale
List of disasters
List of nuclear reactors - a comprehensive annotated list of the world's nuclear reactors