If you are seriously interested, there are several books I can recommend, however, they are kinda thick and deal a lot with nuclear engineering. ;)
In the unlikely event that enough radiation should leak out of the reactors to be able to travel that far and have an effect on us, we are very lucky that this season's winds are North Westerly (ie: blowing South Easterly), meaning that any radiation would blow out into the Pacific, in the opposite direction of Korea. Thankfully!
OK, so at your request I won't mock the question...but can I mock the fact that you are asking a bunch of English teachers a question about nuclear disasters and radiation? ::)
I wouldn't worry yourself too much, to put it into perspective I'd say the chances of being injured by a crazy Korean driver are far higher!