One can hope that the complexity, size, potential hazards, and expense of getting power from nuclear reactions can be greatly reduced in the future. Like Charles Babbage's difference engines [1] that were replaced by a whole new way of doing calculations with electronics, I don't think there is any first principle reason small and safe nuclear powers sources couldn't exist. The big problem in discovering/inventing them is the regulations and public fear around radioactive materials. Radioactivity is dangerous but so are a lot of technologies when they first were discovered. Steam power, chemical explosives, oil refining, etc. No one can really tinker around nuclear materials, try new things, and iterate quickly. The US could really help jump start new nuclear tech if they would designate an isolated location where the rules and regulations around handling radioactive material was greatly relaxed. The former test site in Nevada might be a good place.

Fully informed consent for the people working there with each lab spaced out to confine any unexpected high exposures to the people working on their own experiments. A certain portion of the population desires doing dangerous and risky things. Look at all the extreme sports these days. It would be great to create a way to allow them to take dangerous risks that are deeply meaningful, intellectually challenging, potentially financially lucrative, and productive for society at large.