Why not put reactors underwater?

Should you keep your banana in the fridge? Why are ice-cubes easier to eject from top-shelf freezer trays? Why not site nuclear reactors underwater in the ocean to help keep them cool? Why was the tsunami water that hit Japan so dirty? Why did the Fukushima reactors release hydrogen? Where did my some get his altered earlobes? Join Dr Chris for this week's crop of questions from 702, including a look at the nuclear threat from Japan as well as gene therapy for Parkinson's Disease and how sperm get turned on... Like this podcast? Please help us by supporting the Naked Scientists