I assume that the majority of the cost would be to design and build nuclear ships. And it's still worth it, as fuel is 50%-60% of operational costs.

As for drones to handle cases of ports which don't allow nuclear ships to dock: this is just a potential workaround. I kind of guess, that they will just focus on other ports first, and then eventually (like, in 5-10 years timeframe) everyone calms down and just allows such ships to dock in LA / NY / other US ports.