About the nuclear power plant accident

What kind of the accident happened?

What was happening at the nuclear power plant in Fukushima?
We searched why the nuclear power plant accident happened.

【Outline of the accident】

1.In the Fukushima Daiichi nuclear power plant. the facilities for the external power supply and backup power was destroyed by tsunami at 15:30 pm, 11 March, 2011.

2.Because of that accident, the monitor could not work and workers could not know the inside situation. During that time, the critical situation progressed because the emergency generators was also destroyed by tsunami.

3.The steam was filled in the nuclear power plant buildings by the core malt down which caused by the dysfunction of the cooling system.

4.Nuclear plant workers tried to vent and inject sea water in order to cool the reactors. However, hydrogen explosion was occurred at reactor No1, No3 and No4.


However the nuclear plant workers couldn’t understand and check that situation because the unit of radiation was increasing. Additionally the government official didn’t even understand the mechanism of nuclear power plant. Thus the detail information was not accurately understood. Japanese government tried to predict the range of radioactivity proliferation from the weather data.

However that data wasn’t transmitted to Tokyo Electric Power Company. Moreover that data was not reflected in the evacuation order. The evacuation order was issued to the region which formed of concentric circles, centering on the Fukushima nuclear power plant. As a result, evacuated orders was not ordered at that time in Iidate-villadge, Kawamata-Village and namie-name-city though the unit of radiation was high. Tokyo Electric Power Company could not grasp the circumstances in detail. The evacuation order was issued within a 2km radius of the city of Fukushima nuclear power plant at 21:30 pm, 11 March, 2011.

Eventually, the scale of that order became bigger and order was issued a 30km radius of the city of Fukushima nuclear power plant. There are some places where the evacuation order is not still lifted.

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