San Onofre shutdown will mean tight electricity supplies

[FBaggins]

45. I'm not sure that I see your point.

The Inglewood fault wouldn't be the primary risk of a tsunami that could overtop SONG's seawall.

Faults that are farther away present less risk (and the nearest fault line that's prone to significant tsunami is a very long way away).

Worst tsunami recorded? Evidence of a 380 foot tsunami.

I think we're going to have to go with your "granted". There is no place on the planet that is safe from whatever caused that tsunami (meteor?). If an event kills many many millions of people and destroys major cities... it is really a significant concern that there will also be a radiation release that would have killed thousands if they weren't already dead from the wave?

I presume you accept geological evidence, not just recorded human history in that local area

Both are relevant. It isn't really "'WE HAD NO IDEA THIS COULD HAPPEN'"... it's that the risk is below some very very low threshold. Note, for instance, that Japan has increased their definition of an "active fault" to one that has been active at some point in the last 250,000 years (IIRC) instead of 100,000 years. It isn't that it's impossible for a 9.0 quake to hit an area with no faults at all... it's just the risk approaches infinitesimal in the lifetime of a reactor.

We would never build anything but tents if the standard was "absolutely zero risk". You can't build a reactor anywhere in the US because the Yosemite super volcano will take it out some time in the next million years?

The largest recorded tsunami anywhere along the West Coast (let alone just that spot) didn't come close to endangering the sea wall.