I don't know about it posing a problem to this kind of extent, but my dad has a friend who lives in Japan, who seems to think that the levels of radiation are much higher than the Japanese government is claiming to the extent that they have decided not to have children and told my dad that he wouldn't recommend that we visit the country for a loooooong time...though I believe he has no authority to say this with or substantial evidence for it, so I dunno.
Though it wouldn't surprise me if he were right, it all seems very shady to me. I personally expect some pretty nasty side-effects of it to be coming into public knowledge; it can't have been anywhere near as clean and simple as it was made out (just to point out, I know it was horrific and has severly affected the lives of thousands of people), but it just seems to me that there has to be more to it.