10 Worst Nuclear Accidents/disasters In History

According to The International Atomic Energy Agency (INAEA), nuclear and radiation accident/ disaster is defined as “An event that has led to significant consequences to people, the environment or the facility. Examples include lethal effects to individuals, large radioactivity release to the environment, or reactor core melt.” Whether accidental or planned, whatever the form and cause might be, nuclear disaster is a disaster which effects people physically, mentally, emotionally, economically and genetically, altering and damaging genes to cause serious effect to generations to come.

10. Three Mile Island – March 28, 1979


Three Mile Island – March 28, 1979

Three Mile Island accident (US – 1979) falls under scale 5 nuclear power plant accidents. On March 28, 1979, in the wee hours of morning, the Three Mile Island nuclear generating station witnessed a nuclear meltdown of one secondary loop. This nuclear accident released 13 million curies of radioactive gases into the atmosphere and caused a loss of USD 2,400. 10 court cases were also filed on various authorities, concerning this accident, and they took 15 long years to get settled. Fortunately it led to no deaths or injuries.

9. Goiania Accident – September 13, 1987


Goiania Accident – September 13, 1987

More than 240 people were exposed to radiation when a junkyard dealer in Goiania, Brazil, broke open an abandoned radiation therapy machine and removed a small highly radioactive cake of cesium chloride. The accident occurred on September 13, 1987. The environment and surroundings were seriously contaminated. Many buildings had to be demolished. 4 died in this accident. Many children got attracted to the bright blue of the radioactive material, touched it and rubbed it on their skin, resulting in the contamination of several city block.

8. Windscale Pile – October 10, 1957


Windscale Pile – October 10, 1957

The accident took place on October 10, 1957 when a windscale fire ignited plutonium piles and contaminated surrounding dairy farms. The radioactive contamination caused 33 cancer deaths. This was the worst nuclear accident in Britain’s history, ranked in severity at level 5 on the 7-point International Nuclear Event Scale. The fire released an estimated 20,000 curies of iodine-131, as well as 594 curies of caesium-137 and 24,000 curies of xenon-133, among other radionuclides. The incident produced around cancer cases. In addition to this, milk farms were seriously contaminated, dropping milk sales by 15%.

7. Chalk River Nuclear Accident – 1952


Chalk River Nuclear Lab Disaster – December 12, 1952

Chalk River Laboratory (CRL) is a site of major research and development to support and advance nuclear technology, in particular CANDU reactor technology. On December 12th, 1952, a reactor shutoff rod failure, combined with several operator errors, led to a major power excursion of more than double the reactor’s rated output at AECL’s NRX reactor. INES rated the incident as level 5. A series of hydrogen gas explosions hurled the four-ton gasholder dome four feet through the air where it jammed in the superstructure. Thousands of curies of fission products were released into the atmosphere, and a million gallons of radioactively contaminated water had to be pumped out of the basement and “disposed of” in shallow trenches not far from the Ottawa River. The core of the NRX reactor could not be decontaminated; it had to be buried as radioactive waste. Young Jimmy Carter, later U.S. President, then a nuclear engineer in the U.S. Navy, was among the hundreds of Canadian and American servicemen who were ordered to participate in the NRX cleanup following the accident.

6. Castle Bravo – March 1, 1954


Castle Bravo – March 1, 1954

Bikini Atoll, Micronesian Islands in the Pacific Ocean was the site of more than 20 nuclear weapons tests between 1946 and 1958. Castle Bravo was the code name given to the first U.S. test of a dry fuel thermonuclear hydrogen bomb. The test was performed on March 1, 1954, at Bikini Atoll, Marshall Islands. When the weapon was detonated, an explosion took place, leaving a crater of 6,500 feet (2,000 m) in diameter and 250 feet (75 m) in depth. Castle Bravo was the most powerful nuclear device ever detonated by the United States, with a yield of 15 Megatons which was far exceeding the expected yield of 4-6 Megatons. This miscalculation led to a severe accidental radiological contamination ever caused by the United States. In terms of TNT tonnage equivalence, Castle Bravo was about 1,200 times more powerful than the atomic bombs which were dropped on Hiroshima and Nagasaki during World War II. Moreover, the radiation cloud contaminated more than seven thousand square miles of the surrounding Pacific Ocean, including small islands like Rongerik, Rongelap and Utirik. These islands were evacuated, but generations to come where affected. Natives have since suffered from birth defects. A Japanese fishing boat, Daigo Fukuryu Maru, also came into contact with the nuclear fallout, causing illness to all crew members with one fatality. Fish, water and land were seriously contaminated, making Castle Bravo one of the worst nuclear accidents.

5. Soviet Submarine K-431 Accident – August 10, 1985


Soviet Submarine K 431 Accident – August 10, 1985

The Echo II class Soviet submarine K431 suffered a massive explosion during refuelling in Vladivostok, Russia. The explosion produced a radioactive cloud of gas into the air. Ten sailors were killed in the incident and 49 people were observed to have radiation injuries with with 10 developing radiation sickness. Moreover Of the 2,000 involved in cleanup operations, 290 were exposed to high levels of radiation compared to normal standards. TIME magazine has identified the accident as one of the world’s “worst nuclear disasters”.

4. Mayak Nuclear Plant – September 29, 1957



Mayak Nuclear Plant – 1957

Mayak Nuclear Plant, also known as Chelyabinsk-40 and later as Chelyabinsk-65 is one of the biggest nuclear facilities in the Russian Federation. It is an integral part of the Russian nuclear weapon program. The facility has experienced 20 or more accidents affecting at least half a million people in the past 45 years. The most notable accident occurred on 29th September, 1957 exposing the Soviets Regiems secret. The failure of the cooling system for a tank storing tens of thousands of tons of dissolved nuclear waste resulted in a chemical (non-nuclear) explosion having a force estimated at about 75 tons of TNT (310 gigajoules), which released some 2 million curies of radioactivity over 15,000 sq. miles affecting at least 200 people died of radiation sickness, 10,000 people were evacuated from their homes, and 470,000 people were exposed to radiation. Victims were seen with skin ‘sloughing off’ their faces, hands and other exposed parts of their bodies. A large area was left barren and unusable for decades and maybe centuries. The accident caused a large number of fatalities, thousands were injured and surrounding areas were evacuated. It is categorized as a level 6 “serious accident” on the 0-7 International Nuclear Events Scale.

3. Chernobyl Disaster – April 26, 1986


Chernobyl Disaster – April 26 1986

The Chernobyl disaster was a nuclear accident that occurred on 26 April 1986 at the Chernobyl Nuclear Power Plant in the Ukrainian SSR (now Ukraine). The accident took place in the reactor number 4 near the Pripyat town. There was a sudden power output surge, and when an emergency shutdown was attempted, a more extreme spike in power output occurred. This led to a reactor vessel rupture which caused a series of explosions. Belarus, Russia, and Ukraine were seriously affected and about 60% of the fallout landed in Belarus. From 1986 to 2000, 350,400 people were evacuated and resettled from the most severely contaminated areas of Belarus, Russia, and Ukraine. World Health Organization (WHO) estimates the number of deaths to be 4,000 while a Greenpeace report puts this figure at 200,000 or more. Among these varied figures 31 deaths were confirmed to be caused by the accident. The World Health Organization reported the radiation release from the Chernobyl accident to be 200 times that of the Hiroshima and Nagasaki nuclear bombs combined. It is considered the most serious nuclear power plant accident in history, and is the only accident classified as a level 7 event on the International Nuclear Event Scale.

2. Fukushima Disaster – March 11, 2011


Fukushima Disaster – March, 11 2011

A massive 8.9-magnitude quake hit northeast Japan on Friday, causing dozens of deaths, more than 80 fires, and a 10-meter (33-ft) tsunami along parts of the country’s coastline. Homes were swept away and damage was extensive. And the disaster didn’t end with this. Eleven reactors at four sites near Japan’s northeast coast were shut down per seismic emergency procedures. Five reactors at two sites in the Fukushima prefecture declared emergencies due to loss of normal site power and backup emergency power. According to a British nuclear expert the explosion at the Fukushima I nuclear plant looks likely to be a “significant nuclear event” with a bigger impact on public health than the 1979 meltdown at Three Mile Island. As of 15 March, the Finnish nuclear safety authority estimated the accidents at Fukushima to be at Level 6 on the INES. On 24 March, a scientific consultant for Greenpeace, working with data from the Austrian ZAMG and French IRSN, prepared an analysis in which he rated the total Fukushima I accident at INES level 7. The accident caused nuclear contamination in the surrounding environment, water, milk, vegetable and other food items. People living in surroundings were moved to safe shelters and food grown in the area was banned for sale. The Japanese government in handling the situation in the most efficient and amazing way that anyone can imagine. Screening is being done and people are given proper medical care. Initially 3 workers were affected by the radiation.

1. Atomic Bombings of Hiroshima and Nagasaki – World War II, 1945


Atomic Bombings of Hiroshima and Nagasaki – World War II, 1945

These nuclear disasters were not accidents but an ugly example of human wrath and violence. It was a result of the war between two big powers of the world. During the final stages of World War II in 1945, the United States conducted two atomic bombings against the cities of Hiroshima and Nagasaki in Japan, the first on August 6, 1945 and the second on August 9, 1945. This nuclear disaster caused innumerable deaths and serious physical, emotional and genetic problems which were faced by many generations. Families were destroyed and people lost their loved ones, home and money all in one day. Within the first two to four months of the bombings, the acute effects killed 90,000–166,000 people in Hiroshima and 60,000–80,000 in Nagasaki. 15–20% died from radiation sickness, 20–30% from flash burns, and 50–60% from other injuries, compounded by illness. Roughly half of the deaths in each city occurring on the first day. A study states that from 1950 to 2000, 46% of leukemia deaths and 11% of solid cancer deaths among bomb survivors were due to radiation from the bombs. Even after such a huge scale disaster and setback, the Japanese people faced this situation with courage and resolution and made Japan one of the leading countries of the world.