This release of lethal levels of ionizing radiation is not a one time finite occurrence as I understand it, but an ongoing happening...
Recently I was at a seminar where Fukshima was one of the topics. The speaker, who seemed pretty knowledgeable about the situation, said things like "No stopping Fukashima...Northern Japan is 'finished'...Fukishima keeps 'giving'..." The West Coast, and especially Hawaii, are going to suffer too. It sounded like another reason for me to step up my plans to move east a state or two.