History, Stories

9 Worst Nuclear Disasters In The History According to INES

We rounded up some of the world’s worst nuclear disasters ranked by their placement on the International Nuclear and Radiological Event Scale (INES).

1. SL-1 Experimental Power Station

Idaho, USA

3 January 1961


This nuclear disaster was caused by improper removal of control rod responsible for absorbing neutrons in the reactor core, resulting in a steam explosion and meltdown.

The accident killed three operators while 22 other workers were fully exposed to the radiation.  790 other people exposed to harmful levels  during cleanup and disposal of radioactive wastes.

$4.3 million worth of property loss was estimated from the incident.

2. RA-2 Facility

Buenos Aires, Argentina

23 September 1983


This nuclear accident was caused due to operator error while re-configuring a fuel plate. leading to a nuclear reactor assembly meltdown.

nuclear accident the operator died 2 days later after exposure to massive doses of gamma and neutron rays. 17 others in the facility absorbed radiation doses.

3. Tokaimura Nuclear Accident

30 September 1999

Tōkai, Japan


This need a disaster occurred when workout at the nuclear power plant  put highly enriched Uranium  inner precipitation tank more than what was permitted, causing an instantaneous and uncontrolled nuclear fission.

As a consequence of this incident 2 workers died at the spot. 667 workers , emergency personnel and nearby residents exposed to excess radiation.

The estimated cost of property loss in this accident is estimated to be worth USD 120 million.

4. Windscale Piles

Buenos Aires, Argentina

23 September 1983


The accident broke out when one of the two reactor cores caught fire igniting 11 tons of Uranium. It was ablaze for three days before it was put out. Substantial amount of radioactive contamination were released as far as mainland Europe.

It took 10 years to clean up the accident site and it caused dollar 30 million of revenue loss. The cleaning up process is still undergoing and is estimated to last up to 2037 and cost $102 billion  for the whole process.

5. Three Miles Island

Pennsylvania. USA

28 March 1970


The incident broke out when a pressure valve in one of the reactors failed to close, releasing contaminated cooling water into adjoining buildings. Operators made critical containment errors and by next morning the core heated short of meltdown, but radioactive steam had already poured out of the plant.

As a result 140,000 people evacuated the place. A study found significant increase in Cancers among residents who lived within ten miles of the area. No deaths were reported though.

6. Goiania Accident

Goais, Brazil

13 September 1987


Two thieves broke into an abandoned private hospital, disassembled a teletherapy unit and took off with a small Steel capsule containing highly radioactive caesium chloride. Several people handled the capsule and even let loose the content.

The incident killed 4 people  whereas 112, 000 people were examined  out of which 249 were found to have observed high radiation levels. 1,000 people identified with small doses. Topsel removed on contaminated sites.  40 houses demolished.

The local Court ordered USD 750, 000 total worth of compensation, which was to be given by the  National Nuclear Energy Commission of Brazil.

7. Mayak Plant

Kysgtym, Russia

29 September 1957


Cooling system failed to work, causing a non-nuclear explosion with a force equivalent to between 75 and 100 tons of TNT.

In the incident 200 people died from radiation 10000 people evacuated. The people 470,000 contaminated. Radioactive fallout cloud registry hundred kilometres away contaminating an 800- square KM area now known as the East-Ural Radioactive Trace.

Since it was a hidden project of Russia, there are no estimates of the total loss of revenue.

8. Chernobyl Nuclear Plant

Chernobyl Ukraine

26 April 1986


On April 26, 1986, the world’s worst nuclear power plant accident to date occurred at Chernobyl in Ukraine. Experts believe that thousands of people died from radiation exposure and as many as 70,000 suffered from severe poisoning. The full toll is still being tallied up to this day.

An electrical test by workers at one of the four reactors created a sudden power surge, leading to a series of blasts that blew off the 1,000-ton steel top of the reactor.

The incident led to the death of  32,  whereas dozens suffered radiation burns.  600000 people involved in cleanup and recover were exposed to radiation. Total number of deaths may reach 4,000 from among those exposed.

The Russian Ukrainian and Belarus government sobbing hundreds of billions of dollars to the affected people for the for each in effects that are continuing until now.

9. Fukushima, Daiichi Nuclear Power Plant

Fukushima, Japan

11 March 2011


The accident was caused due to earthquake and tsunami that struck eastern Japan. Causing a series of equipment failure nuclear meltdowns and releases of radioactive materials.

It led to forced evacuation of half a million residents. 1,600 deaths related to evacuation conditions. 159,128 a resident evicted from exclusion zone no deaths yet from radiation exposure 11580 square miles land area contaminated.

The disaster had caused  a total loss worth USD $250 to 500 billion.