Floating in the ocean means they won't be susceptible to damage by earthquakes or tidal waves, their size should make them essentially immune to any storm damage, other than that they are no safer nor any less safe than any other nuclear reactor.

Risk management and other environmental concerns are always an issue, but the risks that nuclear presents in today's context may be offset by the energy produced. I would be interested in learning more about offshore nuclear and how those plants would minimize potential risks. I can see that, if the plants are far enough offshore and away from population centers there could be a benefit there in the event of a radioactive discharge, but what about the added risk from storms in the areas chosen to locate the plants? Is it significant in terms of additional safeguards that would be required compared to the risks inherent in on shore plants? And if there is an accident, how does the offshore location offset the risk of airborne radiation other than buying time before the radiation arrives?

These are the questions that occur to me immediately before I would personally form an opinion about offshore vs. onshore plants.

EDIT: In case anyone has overlooked the comments beneath Dr. Redthumb's response, there is some interesting and useful information about tidal waves, etc. there.

this sounds like a silly idea. Spilling nuclear material into the ocean? contaminating the food chain there.

The question should be how safe are offshore windfarms? answer safe and credible

Any discussion of nuclear power should be prefaced by the fact that Uranium is a non renewable resource and therefore subject to declining future availability. I agree with Frank that clean renewable energy is the only sustainable option.

Why offshore?

Natural gas and coal more harmful than nuclear power

http://www.giss.nasa.gov/research/briefs...

Nuclear power is too expensive these days. [1]

Not likely. Costs ere too high