The Nuclear Disaster

Soon after the quake, tsunami waves swept into coastal regions, including at the Fukushima Daiichi nuclear power plant, operated by Tokyo Electric Power (TEPCO).

The power supply and reactor cooling systems at the plant were damaged, causing atomic fuel inside three of its six reactors to overheat and eventually melt down.

The government initially ordered the evacuation of residents living within three kilometres of the plant and told others to stay indoors to avoid nuclear fallout.

The evacuation order gradually expanded in the following days, a move that caused public criticism of the government’s response as slow and confusing.

Work crews scrambled, but they failed to cool the runaway reactors.

On March 12, the plant had to open a vent in a reactor to release pressure building inside. The step ejected significant radioactive materials that blanketed the vast farming and industrial region as well as the Pacific Ocean shoreline.

On the same day, a hydrogen explosion ripped through a building encasing Reactor One. It was followed by the second explosion two days later at a building housing Reactor Three. On March 15, a third explosion hit a building for Reactor Four.

Despite the blasts, the reactors remained relatively intact. But radioactive materials continued to leak.

Then-Emperor Akihito on March 16 made an emergency television address in a bid to reassure a worried public.

In December 2011, the government said it had brought the reactors to the state of “cold shutdown”, meaning that they were kept stably cool with water and emission of radioactive materials was significantly reduced.