I've recently listened to the Skeptics Guide to the Universe (SGU) podcast and there's some very interesting stuff about how the Fukashima plant's reactors work and what future problems there could be.

Not sure I can do it justice here so I'll link to it.

http://www.theskepticsguide.org/
Episode 296 named skepticast2011-03-16 and skip to about 41:15 for the interview.

Hindsight is a great thing.

These 6 nuclear plants shouldn't have been built where they were.

Lets hope the problem can be brought under control... and soon.