The full story of Fukushima has not really been comprehensively told, at least in English language media. I'm not really sure that new reactors would necessarily be safer than Fukushima Daichi unit 1, because that unit had an isolation condenser system. The IC is exactly the type of passive safety system that is touted with new designs -- it can keep the reactor cool for a couple of days just by turning a couple of valves, and it can operate indefinitely if its water supply is topped off by, for example, a firetruck. Supposedly the system automatically activated, but then was manually deactivated by reactor personnel before the tsunami arrived to avoid shock cooling the reactor. After the tsunami arrived, the system was not turned back on again apparently out of confusion, but exactly what happened is still mysterious to me.

All of that said I still think that nuclear is the safest and least environmentally damaging method of power generation we've yet invented. Like air travel, due to radiation's mysteriousness, it's held to a much higher standard of safety and environmental impact than other forms of power generation, and that has led to gross distortions in perception and regulation that lead us to have less safety and a worse environment.

Still, it took 2000 people some four days to get all four reactors at Fukushima Daini to cold shutdown.

In July 2019 a decision was made to decommission Fukushima Daini in response to local demands for a decision. It will take more than 40 years to decommission the plant.