I don't know if people think about it economically. If they did then you might say:
There is a nuclear reactor near here.
If there is a 9+ magnitude quake with a matching tsunami then the water surge will probably kill you. If you survive that you may have to evacuate for a couple of months while we get the nuclear plant back into a stable configuration. This has never happened in recorded history but it is possible.
Are you sure you want to buy/rent this house and live here?
Hammock your statement "Nuclear accidents on the other hand are something that we can prevent, either by more robust disaster planning, or by not having nuke plants in sensitive areas to begin with." implies that we haven't prevented them, when in fact we have. Japan has had very large earthquakes before and their nuclear facilities have come through unscathed. This particular event will, in all likelyhood, kill no one out right and probably not change the life expectancy in any measurable way for more than a handful of people. So while the statistically amazingingly unusual earthquake + tsunami got through the back up cooling system defenses, the 'worst possible' scenario you might imagine, and no one has been killed? I'm pretty sure most people would take that bet and decide to live there.
They would be even more likely if they realized that just flying on a commercial airliner once a year has a better chance of killing them.
I understand the fear that radiation induces in people, they can't see it, they feel like they can be 'dead' already and not know it, and there really isn't a good way to hide from it (unless perhaps you have a lead lined shelter). But it is more of a phobia than a rational fear. There are many places you can live where there is no risk of a nuclear accident and if a person's phobia is strong, they may choose to live there, just as people who fear of heights may choose to live in single story structures.
There is however an even bigger threat, for which we completely understand the threat and are not doing a damn thing about. Yup, the bad news is that pretty much anywhere on the planet you can be killed by an Asteroid impact [1] which, surprisingly, is about as likely than a 9+ quake and a tsunami [2].
And perhaps more telling, given the inverse square law, you can actually build a shelter that is impervious to any event at any reactor for any given distance, but you can't do that for a space rock.
[1] http://neo.jpl.nasa.gov/risk/
[2] Paleoseismic evidence shows that great earthquakes or earthquake couplets occur about every 230 years (http://www.gps.caltech.edu/~sieh/publications/a10.html).