Nuclear ships are technically possible, but have a massive number of downsides.
- The construction cost would be significantly higher than a conventional ship.
- Reactors are far from trivial, so you'd double or triple the crew required.
- Shipbreaking would become even more of an issue than it already is. You can't just beach a ship like this in Bangladesh and have a bunch of untrained people attack it with plasma cutters.
- The ship would be a huge target for pirates and terrorists. It's essentially a floating dirty bomb, after all, just waiting for the USS Cole treatment.
- A lot of countries would not accept nuclear ships, both due to perceived security risks and for more ideological reasons.
... and that's probably only the tip of the iceberg.
Nuclear is barely economically viable with land-based large-scale nuclear power plants running for 50+ years. They are an attractive option for some military ships, but I doubt anyone would be willing to risk it for regular commercial shipping.
> They are an attractive option for some military ships, but I doubt anyone would be willing to risk it for regular commercial shipping.
There's been a few built over the years, mostly for research.
Russia apparently still operates one.
https://en.wikipedia.org/wiki/Sevmorput
Despite hurtles you've pointed to it is still being considered:
https://www.spglobal.com/commodity-insights/en/news-research...
> This source of power confers some advantages. "You will have ships going maybe 50% faster because the fuel is essentially free once you have made the upfront capex investment," Sohmen-Pao said.
You achieve ~0 emissions AND avoid increasing transit time going with pure sailing ships.