Hyperion power has plans to produce a reactor that you can transport on the back of a truck, generates 30 megawatts, lasts 8-10 years, and is recycleable. Not only that, they plan to start production levels at 400 a year, and ramp up from there.
If this thing actually delivers on it's promise, I can see transport ships switching to these for energy.
The cost for energy is about 5 cents KWh and would probably go down with higher production rates (although 400 reactors a year sounds like a lot to me).
The technology is apparently "walk away safe", meaning you don't even have to monitor the reactor's operation, it's self modulating, and can't go critical and explode by the very nature of the system.
http://www.techrockies.com/story/0017490.html