Charlie Martin has the best explanation I've yet read about the Fukushima reactor meltdown. It shouldn't be a surprise to anyone that the media is over-hyping the danger. Martin does a great job explaining the processes going on in and around the reactor, as well as highlighting the anti-nuclear agenda of many of the "nuclear power experts" that the media is running to for analysis.
Note: don't interpret my anti-sensationalism as a complete pass for the nuclear industry. It's pretty foolish to put a nuclear plant right near the ocean without sufficiently protecting the coolant supply from contamination by tsunami.