The NS Savannah is the only nuclear powered commercial vessel ever built. It is a very interesting evolutionary dead end. And right now it is gently decaying in Baltimore Harbor where Gene B took us by it.
In The Evolution of Everything, Matt Ridley extends the idea of evolution from biology to everything. Including idea and ships. The Savannah was an experiment that failed but a lot was learned.
The main thing that was learned is that people are not yet comfortable with nuclear power. It would be interesting to know how many power plants, submarines, aircraft carriers, satellites and other thing there are in the world being fueled by nuclear power.