Chornobyl Among Nuclear Disasters

Nuclear disasters with catastrophic consequences, like Chornobyl, dominate the public’s perception of what could become of potential failures in nuclear facilities. Prominence of nuclear bombs and significant meltdowns seem to suggest that while any resource-related mishaps may be problematic, the failures of nuclear-powered sources bring about exceptionally tragic outcomes. While that may be true in particular cases, they are not representative of nuclear-related incidents as a collective. It is, therefore, necessary to further analyze nuclear incidents and consider the extent to which misfortune arises from the use of nuclear power itself, and how much can be attributed to human errors and intentions, substandard technological conditions, and various external factors–as is the case with any other type of incidents and disasters.

Nuclear incidents occur under various circumstances and affect its victims in more ways than one, serving as a reminder to stay vigilant in everyday situations. By presenting a broader spectrum of incidents related to nuclear use and radiation, we can better contextualize Chornobyl’s role in the history of nuclear and radiological disasters, recognizing it as the anomaly it is. With a biological and cultural impact that outlasts any other industrial nuclear incidents in history, the legacy of Chornobyl remains our ongoing subject of study.

Radiological Disasters from 1896-2020

The graphs of radiological disasters from 1896-2020 present the collection of all radiological disaster by countries, causes and deaths as documented by Johnston’s Archive.

The following table records nuclear and radiological incidents selected from the aforementioned collection. They serve as representative examples, highlighting some of the most frequent causes for nuclear and radiological incidents in addition to nuclear power plant failures. Those cases include malfunctioning reactors on a smaller, portable scale, criminal acts with radiological materials, orphaned and stolen sources, and nuclear testing for military use. Some of the lesser-known cases discuss the danger of nuclear and radiological materials at a more personal level, suggesting that while such incidents may occur more frequently, their potential harm can still be managed and mitigated. As for the more noted incidents, we emphasize factors contributing to its transpiration that may not be unique to “nuclear” accidents and therefore consider human operation rather than nuclear energy as the primary point of caution.

Event Type of Accident Date Deaths
K-19
 Submarine reactor 07/04/1961 ==22=={description=”over a span of two years”}1
K-27
 Submarine reactor 05/24/1968 ==9=={description=”all 144 of the crew poisoned and injured”}2
Texas radiological assault
 Criminal acts 1974 ==0=={description=”target of assault injured”}3
Tammiku Stolen Source
 Criminal acts 10/21/1994 ==1=={description=”4 injuries, 1 family dog died”}
Guangzhou radiological assault
 Criminal acts 2002 ==0=={description=”target of assault injured”}4
San Jose Radiotherapy incident
 Radiotherapy incident 08/22/1996 ==7-17=={description=”debates on whether the deaths were caused by the radiotherapy exposure or the illness itself, 71 injured”}
Orphaned source in Goiania Brazil
 Orphaned source dispersal 09/13/1987 ==5=={description=”20 injuries”}5
Castle Bravo Nuclear testing
 Nuclear testing 03/01/1954 ==1=={description=”93+ injuries”}6
SL-1 Reactor excursion
 Nuclear power plants 01/03/1961 ==3=={description=”22 injuries”}7
Three mile island
 Nuclear power plants 03/28/1979 0
Fukushima Daiichi
 Nuclear power plants 03/11/2011 ==1=={description=”1 confirmed cancer death attributed to radiation,1000-2000 deaths attributed to evacuation and other disater-related causes”}

{.show-active}

.ve-map basemaps=OpenStreetMap,Esri_WorldPhysical,Stamen_Watercolor sticky right - Q39265625 8 marker “Abrosimov Bay” - Q80413 8 marker “Novaya Zemlya” - Q26676 8 marker “Texas” - Q1356491 8 marker “Tammiku” - Q16572 8 marker “Guangzhou” - Q3070 8 marker “San Jose” - Q83189 8 marker “Goiania” - Q152225 8 marker “Bikini Islands” - Q1221 8 marker “Idaho” - Q488690 8 marker “Dauphin County, PA” - Q161176 8 marker “Fukushima”

K-19

The K-19 submarine was the first ballistic-missile equipped nuclear submarine, carrying three ballistic missiles with a range of 650km. During its first mission as a US attacker on June 18, 1961, the submarine experienced testing pressure that exceeded its designed pressure at ==Abrosimov Bay=={flyto:Q39265625,7}, resulting in damaged piping in the primary cooling unit. This led to a drop in pressure, causing the reactor water to boil and the reactor room temperature to reach 140°C, resulting in a fire.

With no coolant system in place, the crew had to fix the leak using raincoats and gas masks. They managed to develop an effective cooling system with a drinking water supply, preventing fuel melting and a steam explosion. However, they were exposed to high levels of radiation, approximately ==50-60 Sv (5000-6000 rem)=={description=”According to the International Commission on Radiological Protection, 1 Sv results in a 5.5% probability of eventually developing fatal cancer based on disputed linear no-threshold model of ionizing radiation exposure”}. Eight crew members who fixed the leak died within days. After replacing the reactor units, the K19 submarine was put back into use, but 22 out of the original crew of 139 died due to radiation exposure. 8

Human Factors

The person in charge of the test failed to report the damage to superiors and did not perform necessary repairs. Additionally, the captain did not respond immediately after the leak occurred. The crew members were sworn to secrecy, routinely lying to doctors during checkups for decades following the accident.

image src=wc:K-19.jpg caption="Problem-plagued K-19, disabled in the North Atlantic on 29 February 1972. Picture taken on board of the US Navy plane."

K-27

The K-27 was sent off on a five-day trip to conduct checkups for a 70-day mission, collecting data on two experimental liquid metal-cooled reactors which featured a new design intended for the Soviet army. The goal was to have the first USSR submarine remain submerged for 50 consecutive days.

However, the system had a tendency to leak steam, leading to oxidation of the liquid metal coolant and necessitating regular clean-up. A coolant failure occured, possibly caused by the accumulation of oxide particles, resulting in overheating and the release of radioactive gas into the engine room. The submarine resurfaced at ==Novaya Zemlya=={flyto:Q80413,7}This incident led to the deaths of nine individuals and the poisoning of all 144 crew members. 9

Human Factors

The exhausted crew of the submarine faced a series of alarming oversights and neglect that put their health and safety at risk. Objections raised about the need to clean the reactor coolant were overlooked. The radiation detector in the compartment was switched off, and the crew was not monitoring their radiation dosimeters.

When the submarine returned to dock, most of the crew members exposed to radiation were compelled to walk back to the base. Several members were left on board the submarine to “keep watch,” further exacerbating their exposure. A lack of proper medical checkups followed the incident, with many crew members being declared healthy by military doctors without thorough examination.

The captain did make a crucial decision to ignore orders from the division to cut the engines and remain in the submarine. Recognizing the dangers of prolonged exposure, he took action to safeguard the crew by preventing further hours of potential radiation poisoning.

image src=wc:The_dead_sailors_of_the_submarine_%22K-27%22.jpg caption="The deceased sailors of the submarine K-27"

Texas Radiological Assault

A man from ==Harris County, Texas=={flyto:Q26676,7} deliberately exposed his 11-year-old son to radiological material on multiple occasions, resulting in serious consequences. The man had obtained capsules of ==Cesium 137=={description=”a radioactive isotope commonly used in medical devices, gauges, and also produced as a byproduct of nuclear weapons and reactors. It is worth noting that approximately 27 kg of Cesium 137 was generated during the Chornobyl disaster.”} 10 and used under 5-7 occasions, placing it inside headphones, pillows and cushions used by his son. In 1973, a plastic surgeon diagnosed the boy’s skin lesion as being radiation-induced, confirming the harmful effects of the exposure.

As a result, the boy underwent 16 operations between 1974 and 1978, including numerous skin grafts and castration. The man was sentenced to five years in prison. 11

image src=wc:Strahler_CS137.jpg caption="137 Cesium radioactive source/emitter"

Tammiku Stolen Source

Three brothers stole Cesium 137 from a nuclear waste factory in ==Tammiku, Estonia=={flyto:Q1356491,7}. One of the brothers placed the stolen metal block in his jacket pocket. He was hospitalized within 4 days and passed away just two days later, with the cause of death determined to be kidney failure, showing no signs of radiation injury. Unaware of the danger, the victim’s stepson placed the metal in a kitchen drawer. After eight days, he too was hospitalized with radiation burns detected on his body. The authorities were promptly notified.

The man who carried the stolen source home received a dose of ==183,000 rads=={description=”rad stands for radiation absorbed dose and measures the amount of energy deposited per unit of weight of human tissue. A rem is the dosage received from the exposure to a rad. It is the number of rads multiplied by the quality factor of the particular source of radiation.”} 12 to his thigh and a whole-body dose of 4,000 rads. Other family members also received whole-body doses ranging from 100 to 400 rads. Tragically, even the family dog, which slept near the metal, succumbed to the radiation exposure and died. 13

Guangzhou Radiological Assault

A radiology scientist based in ==Guangzhou, China=={flyto:Q16572,7} used ==Iridium 192=={description=”Iridium 192 is a man-made radioactive element commonly utilized in the medical field to combat cancer cells, produced through the irradiation of nonradioactive iridium in a nuclear reactor. “} pellets to target his colleague and former business partner. With forged documents, the scientist obtained an industrial machine containing Iridium 192 and enlisted an accomplice to help. They installed the machine above the ceiling panels in the victim’s office and activated it when the victim was present.

After approximately two months, the victim began to suspect a connection between his deteriorating health and radiation exposure. The primary victim was exposed to a dose ranging from 70 to 150 rads, while an additional 78 hospital staff members were also injured.14

San Jose Radiotherapy Incident

The ==San Jose=={flyto:Q3070,7} radiotherapy incident in 1996 involved a significant error in a ==Cobalt 60=={description=”Cobalt 60 (Co-60) is a radioactive isotope used in medical applications for radiotherapy treatment. It is produced as a byproduct of nuclear reactors when metal structures, such as steel rods, are exposed to neutron radiation.”} radiotherapy unit, leading to overdosages of approximately 60%. This incident resulted in the deaths of 7 to 17 individuals, although there were debates regarding whether the deaths were caused by the radiotherapy exposure or the underlying illnesses themselves. Additionally, 81 individuals suffered injuries as a result of the overexposures. 10 15

image src=wc:Hospital_San_Juan_de_Dios._San_José._Costa_Rica.jpg caption="Hospital San Juan de Dios. San José"

Orphaned Source in Goiania Brazil

An abandoned radiotherapy unit in a demolished clinic in ==Goiania Brazil=={flyto:Q83189,7} contained a highly dangerous source of Cesium 137, amounting to 1375 curies. Two individuals dismantled the equipment and sold the source to a local junkyard, unknowingly spreading the radioactive material.

A number of people examined the material closely, took parts of it home, and distributed it among their families. Some even applied it directly to their skin. Certain components were sold to a second junkyard. Initially, doctors misdiagnosed the resulting illnesses as tropical diseases, but later suspected radiation as the cause. Fortunately, a medical physicist intervened and prevented firefighters from disposing of the substance in a nearby river. Authorities were alerted, and areas of contamination were identified. Treatment centers were established in the Olympic stadium to care for the injured.

Approximately 112,800 people were examined, with 129 individuals sustaining injuries and 20 requiring hospitalization. There were five deaths and numerous injuries, including radiation burns, with some individuals needing amputations of fingers. 16

image src=wc:02010019_radioactive_cesium_source_Goi%C3%A2nia_accident.jpg caption="the radioactive source involved in the 1987 accident in Goiânia, Brazil."

Castle Bravo Nuclear Testing

During the Castle Bravo nuclear testing in 1954 as part of the United States’ Operation Castle at ==Bikini Atoll=={flyto:Q152225,7}, prototypes of the first weaponized thermonuclear weapons were tested. The initial shot, codenamed “Shrimp” TX-21, was expected to have a yield of 6 megatons but in reality yielded 15 megatons. 17 A Japanese fishing boat just outside the restricted zone unknowingly received the fallout. The 23 crew members were unaware of the hazardous nature of the material and did not take precautions to minimize their contact with it. Some crew members even tasted the substance.

As a result, all crew members were hospitalized, and aggressive blood transfusions were administered after the captain recognized the sickness. One person died as a result of the exposure. Two hundred and fourty-six islanders residing on islands west of Bikini under US jurisdiction were exposed to the fallout and were evacuated two days later. Some islanders inadvertently ingested the fallout. Later in life, these islanders exhibited a high frequency of thyroid anomalies. Thirty-seven US naval personnel experienced ==beta burns=={description=”Beta burns are burns caused by beta particles. They are shallow surface burns, usually of skin and less often of lungs or gastrointestinal tract, often as results of hot particles or dissolved radionuclides that came to direct contact with or close proximity to the body.”} from the fallout. 18

image src=wc:Castle_Bravo_005.jpg caption="Castle Bravo nuclear test taken on March 1st 1954"

SL-1 Reactor Excursion

The SL-1 reactor was a prototype reactor designed for easy assembly in remote locations at the ==National Reactor Testing Station in Idaho, USA.=={flyto:Q1221,7} The reactor was water moderated and controlled by five aluminum-clad cadmium control rods. While three workers were reassembling the control rod drives on January 3 1961, one worker manually removed the center control rod rapidly over a 0.5-second period, causing the reactor to become supercritical. This resulted in a steam explosion with a total energy release of 1.3 x 108 joules, comparable to 30 kg of TNT. The worker who withdrew the rod was killed instantly by a control rod. The other two workers were burned and thrown by the explosion, with one dying instantly from impact and the other succumbing to head injuries and dying a few hours later. The release of radioactive material was largely contained within the building. High radiation levels delayed emergency responders’ entry into the reactor building. The bodies of the deceased workers were recovered on January 4 and January 9. In total, 22 personnel and responders received radiation doses ranging from 3-27 rads. 19

image src=wc:SL1nuclearpowerplant.JPG caption="SL-1 Nuclear Power Plant"

Powerplant Failures: Consequences and Responses

Three Mile Island

Overview

On March 28, 1979, the Unit 2 reactor at Three Mile Island, located near ==Middletown, Pennsylvania=={flyto:Q488690,7}, experienced a partial meltdown. This incident is widely considered as the most significant accident in the history of commercial nuclear power plants in the United States despite its limited radioactive releases. It initiated significant changes made in aspects of nuclear power plant operations and regulations, including emergency response planning, reactor operator training, human factors engineering, and radiation protection.

image src=wc:Exelon_Three_Mile_Island_Nuclear_Generating_Station.jpg image src=wc:Oblique_%28view_of%29_TMI_%28Three_Mile_Island%29_-_NARA_-_540028.tif

Events in Sequence

At around 4 a.m., the accident originated in the non-nuclear part of the plant, affecting one of the two reactors. A failure, either mechanical or electrical, caused the main pumps to stop supplying water to cool the reactor. This led to the shutdown of the turbine-generator and the reactor itself. While the pressure in the nuclear piping system started to rise, a relief valve at the top of the pressurizer that should have closed got stuck open. Unfortunately, the control room instruments indicated that the valve was closed, and the staff was unaware that steam was escaping from the open valve, causing a loss of coolant. Alarms and warning lights alerted the operators, but they did not realize the severity of the situation.

Under normal circumstances, the pressure vessel containing the reactor core in the nuclear power plant was always filled with water. There was no need for a water-level instrument to indicate whether the core was adequately submerged. Therefore, the plant staff wrongly assumed that as long as the water level in the pressurizer was sufficient, the core would also be adequately covered.

Unaware of the relief valve being stuck open and unable to confirm the water coverage of the core, the staff made a series of decisions that exposed the core. The malfunctioning valve caused a significant decrease in the pressure of the primary system, resulting in the reactor coolant pumps vibrating and being shut off. To avoid an undesirable situation where the pressurizer would be completely filled with emergency cooling water, the flow of water was reduced. Without the circulation of water by the reactor coolant pumps and with a scarcity of emergency cooling water in the primary system, the water level in the pressure vessel declined, leading to overheating of the core. 20

image src=wc:Setcom_at_Three_Mile_Island_Photo.png caption="Technicians enter the Unit 2 Reactor Building on Three Mile Island."

What Went Wrong?

The partial meltdown and minor off-site releases of radioactivity were caused by a combination of equipment malfunctions, personale errors, regulatory laxities, and operational issues.

  • Equipment Malfunction: The pilot-operated relief valve stuck open when it should have closed when the pressure fell to proper levels.
  • Personale Error: Plant operators’ was misled by the instruments in the control room which indicated that the valve was closed and failed to identify the valve was actually stuck open.
  • Regulatory Laxity: The closure of valves for routine maintenance was a violation of a key NRC rule. Once the secondary feedwater pumps stopped, three auxiliary pumps activated automatically but the valves were closed for routine maintenace, the system was then unable to pump any extra water in this accident.
  • Operational Issue: Reactor No. 2 was rushed into service on the last day of 1978 since the utility company would have lost a $40 million federal tax break if waited one day more. 21
Aftermath

In spite of serious damage to the plant, most of the radiation was contained and the actual release have a negligible effect on the physical health of individuals.

22

No acute radiation injuries occurred, and the evidence indicates no chronic radiation injuries resulted. No individual chronic injuries can be attributed to the TMI accident; even claims of statistically observable changes in possible chronic effects (such as cancer) are not consistent with the evidence. Maximum possible dose to any individuals near the plant was about 0.02 to 0.07 rem in the case of a few hundred individuals, which is well below natural background radiation levels. No consistent evidence that radioactivity released during the nuclear accident has had a significant impact on the overall mortality.23

The TMI accident resulted in significant property damage for the plant operator, but no injuries resulted. The main impact of the Three Mile Island accident has been psychological rather than physical.

image src=wc:Anti-nuke_rally_in_Harrisburg_USA.jpg image src=wc:President_Carter_leaves_Three_Mile_Island_-_April_1%2C_1979_%2814492226660%29.jpg image src=wc:Three_Mile_Island_Article_%28FDA120a%29_%288205614095%29.jpg

Impact on Nuclear Industry

Despite the incident at TMI being a significant cause for the American public’s distrust in nuclear industries in the decades to follow, it led to widespread changes across the U.S. commercial nuclear industry that improved regulations and practices.

The NRC was strengthened and the industry established the Institute of Nuclear Power Operations (INPO) to ensure appropriate training, plant management and operations. It expanded its resident inspector program in which two NRC inspectors live near each of the plants and provide oversight of adherence to the agencies’ regulations. It also expanded both safety and performance-oriented inspections and established an operations center staffed 24 hours a day to provide assistance in plant emergencies. 24

Training reforms are among the most significant outcomes of the TMI-2 accident. Training became centred on protecting a plant’s cooling capacity, whatever the triggering problem might be. Events of TMI led to the establishment of the Atlanta-based Institute of Nuclear Power Operations (INPO) and its National Academy for Nuclear Training. Close to half of the operators’ training was in a full-scale electronic simulator of the TMI control room. The $18 million simulator permitted operators to learn and be tested on all kinds of accident scenarios. 25 .ve-media src=wc:Presentation_at_Three_Mile_Island_Nuclear_Plant_Simulator_%2828751374767%29.jpg static caption=”NRC Resident Inspector Zach Hollcraft (center) gives fellows from the White House Leadership Development Program a presentation from the Three Mile Island nuclear plant simulator”

Fukushima Daiichi

Overview

On March 11, 2011, Great East Japan Earthquake and tsunami induced a disaster in northeastern Japan and initiated a severe nuclear accident at the ==Fukushima=={flyto:Q161176} Daiichi nuclear plant. The tsunami inundated about 560 km2 and resulted in a human death toll of about 19,500 and much damage to coastal ports and towns, with over a million buildings destroyed or partly collapsed. The tsunami inundated about 560 km2 and resulted in a human death toll of about 19,500 and much damage to coastal ports and towns, with over a million buildings destroyed or partly collapsed.

The reactors proved robust seismically, but vulnerable to the tsunami. Power, from grid or backup generators, was available to run the residual heat removal (RHR) system cooling pumps at eight of the eleven units, and despite some problems they achieved ‘cold shutdown’ within about four days. The other three, at Fukushima Daiichi, lost power at 3:42 pm, almost an hour after the earthquake, when the entire site was flooded by the 15-metre tsunami. Three employees at the Daiichi and Daini plants were killed directly by the earthquake and tsunami, but there have been no fatalities from the nuclear accident. 26

image src=wc:20200926fukushima02.jpg image src=wc:IAEA_Experts_at_Fukushima_%2802813336%29_%28cropped_3_to_2%29.jpg

Could it Have Been Prevented?

Unlike Chernobyl and TMI, it has often been argued that the unfortunate placement of the Fukushima Daiichi nuclear power plant saw tsunamis at a scale that was unforseen and therefore could not be prevented.

The tsunami countermeasures taken when Fukushima Daiichi was designed and sited in the 1960s were considered acceptable in relation to the scientific knowledge then, with low recorded run-up heights for that particular coastline. But 18 years before the 2011 disaster, new scientific knowledge had emerged about the likelihood of a large earthquake and resulting major tsunami of some 15.7 metres at the Daiichi site. This, however, did not lead to any major action by either the plant operator, Tepco, or government regulators, notably the Nuclear & Industrial Safety Agency.

The methods used by TEPCO and NISA to assess the risk from tsunamis lagged behind international standards

  • Historical Evidence of Disasters: TEPCO and NISA did not give sufficient attention to historical evidence of large earthquakes and tsunamis in the region surrounding the plant.
  • Tsunami Modeling Procedures: There appears to have been deficiencies in the tsunami modeling procedures used by TEPCO. Most importantly, TEPCO did not follow up with sufficient alacrity on preliminary 2008 simulations that suggested the tsunami risk to the plant had been seriously underestimated.
  • NISA Inattentiveness:   NISA failed to review simulations conducted by TEPCO and to foster the development of appropriate computer modeling tools. 27
Fukushima Now: Water Discharge

image src=wc:Rafael_Mariano_Grossi_visits_Fukushima_NPP_%2801815831%29.jpg image src=wc:Fukushima_Decommissioning_%2802110067%29_%2816372350279%29.jpg

Japan announced in April 2021 that it planned to discharge more than 1.25 million cubic metres of treated water stored at the station by discharging it into the sea. The plan was approved by the nuclear regulator in early 2022. The water stored at the tanks at the Fukushima-Daiichi site is treated through a process known as advanced liquid processing system (Alps) to remove most of the radioactivity. Tritium, which cannot be removed by Alps, and some very low levels of other radionuclides, remain in the water after processing.

The water was largely used to cool the three damaged reactor cores, which remain highly radioactive. Some of it has since leaked into basements of the reactor buildings but was collected and stored in tanks. Space for the tanks is running out and the long-term management of the treated water is necessary to allow for the further decommissioning of Fukushima-Daiichi, which has been permanently shut down.

IAEA director has announced that his agency’s “comprehensive, neutral, objective and scientifically sound” evaluation showed that the planned discharge was consistent with global industry and safety standards while its report was “neither a recommendation nor an endorsement” of Japan’s water discharge decision. 28 29

  1. Lowet, Daniel. “K-19 Nuclear Submarine 1961 Incident.” Stanford University, 18 Mar. 2017, large.stanford.edu/courses/2017/ph241/lowet2/] ↩

  2. Johnston, Wm. Robert. “K-27 Submarine Reactor Accident, 1968.” Johnston’s Archive, 1968, 20 Sept. 2007, www.johnstonsarchive.net/nuclear/radevents/1968USSR6.html.  ↩

  3. Johnston, Wm. Robert. “Texas Radiological Assault, 1972.” Johnston’s Archive, 18 Sept. 2007, www.johnstonsarchive.net/nuclear/radevents/1972USA1.html.  ↩

  4. Johnston, Wm. Robert. “Guangzhou Radiological Assault, 2002.” Johnston’s Archive, 2002, 10 July 2022, www.johnstonsarchive.net/nuclear/radevents/2002PRC1.html.  ↩

  5. Johnston, Wm. Robert. Johnston’s Archive, 1987, 11 May 2005, www.johnstonsarchive.net/nuclear/radevents/1987BRAZ1.html.  ↩

  6. Johnston, Wm. Robert. “Castle Bravo Nuclear Test”, Johnston’s Archive, 1954, 29 Nov. 2022, www.johnstonsarchive.net/nuclear/radevents/1954USA1.html.  ↩

  7. Atomic Heritage Foundation. “Idaho Falls.”, Nuclear Museum, Accessed 7 July 2023, ahf.nuclearmuseum.org/ahf/location/idaho-falls/. ↩

  8. Johnston, Wm. Robert. “K-19 Submarine Reactor Accident, 1961.” Johnston’s Archive, 1961, 10 May 2005, www.johnstonsarchive.net/nuclear/radevents/1961USSR1.html.  ↩

  9. Kiryukhina, Yaroslava. “Eyewitness: Tragedy of Soviet Nuclear Submarine K-27.” BBC News, 24 Jan. 2013, www.bbc.com/news/world-europe-21148434.  ↩

  10. Wessells, Colin. Cesium-137: “A Deadly Hazard”, Stanford University, 20 Mar. 2012, large.stanford.edu/courses/2012/ph241/wessells1/#:~:text=During%20the%20Chernobyl%20explosion%2C%20about,were%20expelled%20into%20the%20atmosphere.  ↩ ↩2

  11. Bailey, Edgar, and Martin Wukasch. “A Case of Felonious Use of Radioactive Materials.” Texas Department of Health Resources, www.irpa.net/irpa4/cdrom/VOL.3/P3_64.PDF. Accessed 7 July 2023.  ↩

  12. “Radiation Units.” Minnesota State University, Mankato, admin.mnsu.edu/facilities-management/environmental-health-safety-risk-management/office-of-radiation-safety/radiation-basics/radiation-units/#:~:text=rem%20(Roentgen%20Equivalent%20Man)%3A,1%20rem%201%3D1%20rad. Accessed 10 July 2023.  ↩

  13. Johnston, Wm. Robert. “Tammiku Stolen Source, 1994.” Johnston’s Archive, 1994, 19 Nov. 2011, www.johnstonsarchive.net/nuclear/radevents/1994EST1.html.  ↩

  14. “2020年广州辐射杀人案：医学硕士为报复同行，装放射源致75人中毒_刘春.” 2020年广州辐射杀人案：医学硕士为报复同行，装放射源致75人中毒, 13 Nov. 2021, www.sohu.com/a/500824862_121071281.  ↩

  15. Johnston, Wm. Robert. Johnston’s Archive, 1996, 11 May 2005, www.johnstonsarchive.net/nuclear/radevents/1996CSR1.html.  ↩

  16. Gerli, Meg. “Goiania Nuclear Accident, Brazil 1987”, Stanford University, 24 Mar. 2018, large.stanford.edu/courses/2018/ph241/gerli1/.  ↩

  17. Atomic Heritage Foundation. “Castle Bravo.” Nuclear Museum, 1 Mar. 2017, ahf.nuclearmuseum.org/ahf/history/castle-bravo/. ↩

  18. “‘Bravo’ Both Triumphs and Fails.” Atomicarchive.net, Accessed 7 July 2023. [www.atomicarchive.com/history/hydrogen-bomb/page-17.html.] (https://www.atomicarchive.com/history/hydrogen-bomb/page-17.html) ↩

  19. Johnston, Wm. Robert. “SL-1 Reactor Excursion, 1961”, Johnston’s Archive, 17 Oct. 2007, www.johnstonsarchive.net/nuclear/radevents/1961USA1.html.  ↩

  20. Chien Liu, “The Safety Culture of Nuclear Power”, The Ohio State University, Accessed 7 July 2023. www.nrc.gov/reading-rm/doc-collections/fact-sheets/3mile-isle.html. ](https://u.osu.edu/engr2367nuclearpower/three-mile-island/) ↩

  21. Lambermont, Paige. “Three Mile Island and the Exaggerated Risk of Nuclear Power.” FEE Stories. Foundation for Economic Education. 14 Jan. 2020, fee.org/articles/three-mile-island-and-the-exaggerated-risk-of-nuclear-power/.  ↩

  22. “Backgrounder on the Three Mile Island Accident.” United States Nuclear Regulatory Commission, 15 Nov. 2022, www.nrc.gov/reading-rm/doc-collections/fact-sheets/3mile-isle.html.  ↩

  23. Johnston, Wm. Robert. “Radiological Events–Frequently Asked Questions”, Johnston’s Archive, 30 Aug. 2005, www.johnstonsarchive.net/nuclear/radevents/radeventfaq.html.  ↩

  24. “Three Mile Island Accident.” World Nuclear Association, Apr. 2022, world-nuclear.org/information-library/safety-and-security/safety-of-plants/three-mile-island-accident.aspx.  ↩

  25. “Backgrounder on the Three Mile Island Accident.” NRC Web, 15 Nov. 2022, www.nrc.gov/reading-rm/doc-collections/fact-sheets/3mile-isle.html.  ↩

  26. “Fukushima Daiichi Nuclear Accident.” International Atomic Energy Agency, 1 Nov. 2021, www.iaea.org/topics/response/fukushima-daiichi-nuclear-accident. ↩

  27. Brown, Omer, et al. “What Are the Implications of Fukushima for the Future of Nuclear Power …” Carnegie Endowment of International Peace, carnegieendowment.org/2012/03/06/what-are-implications-of-fukushima-for-future-of-nuclear-power-pub-47414. Accessed 7 July 2023.  ↩

  28. Dalton, David. “Fukushimia Daiichi: Japan’s Nuclear Regulator Approves Plan for Water Release.” Nucnet, 22 July 2022, www.nucnet.org/news/japan-s-nuclear-regulator-approves-plan-for-water-release-7-5-2022.  ↩

  29. “CDC Radiation Emergencies.” Centers for Disease Control and Prevention, 24 Sept. 2020, www.cdc.gov/nceh/radiation/emergencies/measurement.htm#:~:text=The%20amount%20of%20energy%20deposited%20per%20unit%20of%20weight%20of,is%20equal%20to%20100%20rad.  ↩