And yes, I know that there's been an explosion in Fukushima. I never said that the reactor has exploded.
No, but suggesting Alaska and so forth start stocking up on iodide pills is the sort of reaction one has to the reactor exploding and/or spewing radioactive particulates into the air. Hence my clarifying re: explosion vs. exploded, not necessarily for you but for everyone else reading the thread.
I won't deny that a Chernobyl-esque meltdown is not outside the realm of possibility. Chances are good it won't happen--there were a number of contributing factors at Chernobyl that aren't in play here--but it's still a possibility. Just hasn't happened yet, and sitting around worrying about it won't do much except raise your blood pressure. (And frankly I'd worry more about those still in the area surrounding Fukushima, and Japan itself, before I started worrying about possible exposure in Alaska/Hawaii/China/whichever way the wind's blowing...they're more likely to suffer lethal or extremely harmful exposure.)
On a completely different note, the quake http://www.cnn.com/2011/WORLD/asiapcf/03/12/japan.earthquake.tsunami.earth/index.html?hpt=T1, and shifted the Earth on its axis.