What will happen if there is a nuclear explosion in Japan?

Question:

Will it effect the entire world? I dont know much about nuclear plants. Thank you in advance.

Answer:

The direct effect will be in Japan and maybe China and parts of Russia, of course the direct effect is disastrous, it will kill anything and everything in it's range.

The effect on other parts of the world I'm not sure, but for sure the side effects like commerce and manufacture will be hurt a lot and for long time. For example, for now only (5 days from the quake) lots of car factories and electronics closed, so yes it will affect the whole world in some way.