Realised that most modern submarines (and some aircraft carriers) use nuclear power, but destroyers and frigates don’t. I don’t imagine it’s a size thing, so I’m not sure what else it could be.
In: Engineering
The US [did once have nuclear powered surface ships](https://en.wikipedia.org/wiki/Nuclear-powered_cruisers_of_the_United_States_Navy) but they were deemed too expensive to maintain compared to more conventional hydrocarbon means of power.
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