I still found the cause on the accident regarding hardware as well as software is not elucidated yet. The power line company and those who get profit with restarting them are inclined to stress how important restarting is. There are increasing number of people who support those views. For the last 7 years since the accident, they have been able only to visualize a part of the destroyed innder structure of the pressure vessels. Far from taking away the melt down debris etc and consequent decommisioning of the reactors. The contaminated water is still increasing in quatity since they failed to restrice influx of underground water into the area of the nuclear power plant.
It has not been determined if the accident occurred only by Tsunami or by earthquake itself. The records of the water level/pressure level in the pressure vessels rather support the view that the nuclear power plants, especially their tubings, have been destroyed by the earthquake itself. There is a serious question on the quake proof quality ot those reactors. Without knowing how it has occurred, it might be difficult for them to set measures against such natural disaster.
It is also believed the staff at the nuclear power plants could not follow the manuals for accidents. The company had provided 3 versions of manuals to deal with different levels of accidents. The staff, who might be upset at that disaster, could not follow the indications of the manuals which could have lessened the damage or, at least, could have slow down the process of melt down. The top of the nuclear power plant was an engineer of maintenance of the plants, who was not an expert for such accidents. Actually, there have been less training or education for such severe accidents than necessary.
The accident is told to have killed hundreds of the people in the area, even though their deaths are not directly related with the irradiation etc. Tens of thousands of people have still evacuated from their home land due to radiation contamination. Most of them should lose their home land forever.
The accident in Fukushima has not left so much damage as expected from the quantity of the radioactive matter released. It was fortunate that they could stop running the plants at the earthquake despite of the following LOCA. The wind has brought most of the contaminating materials over to the Pacific Ocean. In the next accident, which we have known unfortunately that it could occur at a definite probability, the damage could be much worse. There are 14 nuclear plants in a limited area norht of Kyoto, which could be collapsed in a row and could devastate the Western Japan.
I wonder if we won't learn anything from the accident in Fukushima.