Honestly, I think you've been drinking the anti-nuke koolaid that the scaremongers have been doling out.
This!
I got some RL 'threats' from some locals about a post (not on /.) I made regarding how over-the-top-shrill a suite of anti-nuke 'studies' was WRT radioactive effluent leaking into the ocean from Fukushima. I ended up telling the instigators to fuck off, then blocked them and their friends.
My position is that, yes this leakage is bad, but it is not nearly as dire as these crapware studies were implicating. They didn't even show anything resembling analysis to bolster their argument. It was just a rehash of TMI. "Leakage is BAD!!! Leakage is unacceptable!!1111 Mmmkay!?"
Yes it is bad, but it is not going to sterilize the Pacific basin (this was one of the long term outcomes suggested). So, come back when you have some EVIDENCE that this is going to do anything worse than make it a fairly unwise choice to eat seafood that comes from the regions around that part of the Pacific.
Putting nukes on large floating platforms is a fairly nice way to mitigate a lot of the problems that are most likely to do serious damage to the plant. OTOH... The Pacific is a really vicious bitch when she is unhappy. I have lived within sight of her for most of my life. I never turn my back on her when I am within her reach. ;) I'd want to be shown high-confidence that such a platform cannot break loose, and if sunk would still be functional enough to complete a cold shutdown, without loss of containment.
As people who have been in the Seattle region for a while may recall, we lost a floating bridge because some idiots failed to close the access hatches on the flotation modules after storing a little bit of contaminated water in them, before a major storm. Oops!
So yeah... There'd need to be some serious effort put into making sure cockups like the I-90 floating bridge cannot happen.