What some people can't seem to wrap their head around is that the Reactor itself was rated to 600Gal and was only ever exposed to 150Gal on the day, for which it SCRAMed correctly and shut itself down.
And if the earthquake didn't happen there wouldn't have been that acceleration or the inundation by tsunami.
I find it interesting that some people, like our friend above, like to mask the capabilities of the Reactor design and make sweeping statemnents such as "magnitude 9 earthquakes can cause nuclear accidents" when in fact, the official investigation revealed that this accident was "wholey man-mad" due to a series of management failures.
I think one of the things I find most offensive about the Fukushima accident are all the armchair engineers who, although exercising no real experience, responsibilities, or perceivable judgment in engineering themselves, have no trouble equating hindsight with foresight. It's easy to claim that there were "management failures". You just type it in. A work of a few seconds and you can go on to picking your nose or whatever it is you do when you aren't berating nuclear power plant operators.
I'll note here there was no real attempt on your part to consider the accident. From the beginning, you've been squawking about management failures without giving any thought to what was going on. For example:
This had nothing to do with the reactor technology and everything to do with implementing the proper safeguards, planning and engineering for such a catastrophe. They should have been planning for a 15 earthquake and a tsunami twice the size of this one. They didn't and this is the result.
Why build for a 30+ meter tsunami? If that never happens aside from the occasional near hit by a fair-sized asteroid every few million years, then what is the point of that bit of overengineering aside from just making the whole project a lot more expensive? Keep in mind that the current protection was more than adequate and if they hadn't flooded out all their backup generators, this whole thing would have been a non-story. Now we know that's a problem we can look for it in existing and planned nuclear plants.
But the ignorance of the above quote shines through on the claim that they should have designed for a magnitude 15 earthquake. That ends up being a billion times more energy than the magnitude 9 earthquake that actually happened. There's no known mechanism by which the crust can store that much energy in one place and release it. There may not be enough such energy tied up in all of the Earth's crust to do that.
So it's real easy to play armchair engineer on the internet. On the other hand, it takes extraordinary effort on the part of the nuclear plant operators and their regulators to anticipate all these scenarios despite having a very limited history of reactor failures. Nor do they or their needy customers have unlimited sums of money with which to entertain every possible scenario that the armchair engineer can dump on the internet or implement ridiculous factors of safety just because it makes the armchair engineer feel smug.
Similarly, I understand that nuclear reactors, especially the older ones, are rather complex. Yet no one has thought to consider that maybe the generator placement slipped through the cracks just because of how complex the Fukushima plant was? No it had to be criminal negligence!
Finally, engineering doesn't magically get it right the first time. They learn by doing. So if say, you want a nuclear power plant operator who can meet your exacting standards for not fucking up, then you need to endure a few generations of operators who don't quite get there. If we were to just get rid of the plants and the operators, then we would never acquire the experience.