Why won't Japan shut down their nuclear plants?

Instead of worrying about nuclear meltdown and the death of millions, along with a whole island rendered uninhabitable, why won't Japanese nuclear plants shut down? Why is it so important that they continue to produce electricity? I learned that containment rods control the critical reaction between radioactive materials, and that these rods can stop a reaction. By doing that, wouldn't Japan have one less huge thing to worry about? Am I just ignorant? Is it more complicated than that? Someone please enlighten me.