Counterpoint: we've been powering ships with microreactors for decades.
We just awarded $0.5B to decommission the USS Enterprise (CVN 65), the first nuclear aircraft carrier. More will follow! https://theaviationist.com/2025/06/03/uss-enterprise-dismant...
The DoE has been helping to decomission Los Angeles class attack subs for a while now. Here's a piece on that: https://www.defense.gov/News/Feature-Stories/Story/Article/4...
It require enormous care & effort. It's fantastically costly. Do I think it was worth it? For a mission like this: I think yes. For the good of a nation. And a Nation that hopes to still be around to take care of the problem, the complex decomissioning decades latter. But I have so little faith that private interests will endure and bear their own responsibility for this awesome but deeply corrupting irradiating force.
And it is a money pit.
And then you have things like this: https://www.navytimes.com/news/your-navy/2019/01/10/two-sail...
It's proof that you can build a robust and safe reactor, but like all things under triple constraints it will not be cheap.