About Japan: the problem is that the reactor uses "dirty" fuel. It is a combination of plutonium and uranium (MOX). I suspect that the old fuel rods have bean spread out due to the explosion and the surrounding area is contaminated with plutonium which means you can never return to this place again. It is like a new Tchernobyl. Personally, I am not surprised that the authority has not informed people about this.
http://www.huffingtonpost.com/vivian-norris-de-montaigu/deadly-silence-on-fukushi_b_859241.html
http://www.huffingtonpost.com/vivian-norris-de-montaigu/deadly-silence-on-fukushi_b_859241.html