Nuclear energy is safe. By way of a metric, let’s try a thought experiment: How many deaths can we attribute to the mining, processing, and use of coal for energy, per megawatt-hour? Now, let’s try the same guess for nuclear power.
Here’s something else to review: Randall Munroe of XKCD fame created this comparison chart to help people understand the various dangers of varying levels of radiation exposure. Please, take a moment and review, if you’re at all freaking out about Japan.