unless we're nuclear engineers, there is nothing we can do about the situation besides donate to relief organizations. with no productive actions to take, why should we assume anything?
Even though this is a Fairly Bad Thing, I think crafting an anti-nuclear agenda out of it is a poor move for society as a whole.
Nuclear power has overwhelmingly been shown to be safe, and something can be safe and have unexpected Big Deals at the same time. That's a non-binary attitude that this polarizing subject doesn't exactly favor, as shown by this thread in numerous places.
I mean, that's part of being human, isn't it? Nuclear power is safe. Humans build nuclear power. There will always be a human element...
If those are the only productive actions I can take to ensure this won't happen again, then I think I don't want this to not happen again. Not saying I want this to happen again, but nuclear power is still safer than most of the alternatives.
Of course, you're presenting a vastly incomplete list. We can also do things like:
3 - advocate extra layers of redundancy
4 - analyse what could have been done up-front to eliminate the possibility of this happening given the conditions of the earthquake+tsunami and implement the findings
5 - work to replace older nuclear reactors (with less-safe designs) with new reactors with state-of-the-art safety features
That might not be a bad idea. Not only would there be far fewer fatalities, but we'd be much less reliant on fossil fuels.
That, in turn, would not only forestall global warming, but possibly prevent some of the "hard crash" scenarios that could happen on the way down from the oil peak.
Unfortunately, getting rid of cars would probably be much harder than getting rid of nuclear power plants.
So I'd vote to start on something that's realistically accomplishable in the relatively near term: get rid of existing nuclear power plants, and keep new ones from being built.
Jobs would necessarily have to be much closer to home.
The onset of global warming and the oil peak are starting to prove that building economies around suburbs, highways, and long commutes is unsustainable anyway.
See this great documentary, "The End of Suburbia":
