Last night I watched a documentary about the Seawolf class submarines. I thought it was very generic in that it didn't really touch any technical aspects but then again maybe the most interesting ones might be classified.
But this made me wonder how it is possible to cram 100+ people into a 110m steel tube together with a small nuclear power plant, some rockets and lots of other hardware - and make it run on 4kg of Plutonium (at least that's what I think they said.) Are there significant differences between reactors used on subs vs. those used to make electricity on land? Is there a different safety threshold? It would seem to me that the submarine variety would need better engineering. Is it simply the scale factor? Seems the submarine produces about 45,000hp = 33kw while nuclear power plants are in the 1000mw range, 30,000 times more output? Are my numbers way off?
Which of course raises the question about nuclear space propulsion.