Tokaimura nuclear accident facts for kids

The Tokaimura nuclear accident was a serious event that happened in Japan. It took place at a special factory in Tokaimura, near Tokyo, on September 30, 1999. This factory was used to prepare uranium fuel. The accident happened at a small fuel plant run by a company called JCO.

The main reason for the accident was that workers put too much uranium solution into a tank. This solution contained about 16.6 kilograms of uranium, which was more than the safe limit. The tank was not made to handle this type of solution or to prevent such accidents. As a result, three workers were exposed to dangerous levels of neutron radiation. Sadly, two of these workers later died.

Many emergency workers and people living nearby had to go to the hospital. Hundreds of thousands of others were told to stay indoors for 24 hours to be safe.

What Happened After the Accident?

The three workers who were at the factory when the accident happened were Hisashi Ouchi, Masato Shinohara, and Yutaka Yokokawa. Two of them became very sick from radiation sickness and passed away.

Hisashi Ouchi, who was 35 years old, died 12 weeks after the accident. He was closest to the tank when the accident occurred and was the first person to be severely affected. Seven months after the accident, Masato Shinohara, aged 40, also died.

Experts measured how much radiation each worker received. Ouchi was reported to have received 17 sieverts (sv) of radiation, Shinohara received 10 sv, and Yokokawa received 3 sv. To give you an idea, 8 sieverts is considered a deadly amount of radiation. For Japanese nuclear workers, the maximum safe limit for a year is 50 milli sieverts (which is 0.05 sieverts).

Another 83 workers at the plant were also exposed to more radiation than is normally allowed.

Images for kids

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  Tokaimura Nuclear Plant

See also

In Spanish: Accidentes de Tokaimura para niños