The world’s worst nuclear accidents – 24/7 Wall St.

Although the nuclear age ushered in mankind’s most terrifying weapons, it also held the promise of a powerful and limitless new source of energy. In 1954, the first nuclear power plant became operational in Obninsk, a city southwest of Moscow. Since then, most Western countries, as well as China and India, have built nuclear facilities to power their economies. But almost from the beginning, many people feared the possibility of disaster.

To find some of the world’s worst nuclear accidents, 24/7 Wall St. scoured several online sources to list accidents rated Level 4 or higher, according to the International Nuclear and Radiological Event Scale, or INES. Nuclear accidents are assigned a level ranging from zero to 10 according to a scale developed in 1990 by the International Atomic Energy Agency and the Nuclear Energy Agency of the Organization for Economic Co-operation and Development. Our list does not include military-related accidents and is presented in chronological order.

According to the US Energy Information Association, 31 countries have nuclear reactors that generate 10.3% of the world’s electricity. In the United States, 94 reactors operate in 30 states and produce almost 20% of total annual electricity production. Although nuclear energy does not produce carbon dioxide, it does generate nuclear waste, and this material can remain radioactive and dangerous to people for thousands of years.

There have been very few serious nuclear incidents in the United States. Of most concern was the Three Mile Island accident in Pennsylvania in 1979, an incident that strangely followed the release of the nuclear accident film “The China Syndrome” a few weeks earlier. (Here are the oldest nuclear power plants in the United States.)

Nuclear accidents have occurred for various reasons such as miscalculations involving experiments or tests, human error, or faulty design in some of the facilities. In one case, an old radiotherapy machine stolen by scavengers from a Brazilian hospital was manhandled by numerous people, killing four of them. In Japan, an earthquake and tsunami severely damaged three of the reactor buildings and the fuel in three of the reactor cores melted.

The incident in Japan is one of two Tier 7 events on the list. The other is Chernobyl. There were two Level 6 crashes and four Level 5 episodes. In one Level 5 event, a future US President played a key role in preventing a catastrophe. (These are the states with the most nuclear power plants.)

Click here to see the world’s worst nuclear accidents