If Nuclear power becomes a viable safe and clean energy, how are we going to deal with countries that don't have nuclear technology?

https://www.euronuclear.org/info/encyclopedia/n/nuclear-powe...

There are only 31 nations in the world that has nuclear power.

If, in the unlikely case, we successfully distribute the nuclear technology to the rest of the world. How do we prevent/contain states go rogue and start enriching fuels for nuclear bomb?

This might be a harder problem to solve than technology break through.