I'm pro nuke energy but to pretend there are no downsides is what got us into the climate mess we are in in the first place.
Cost, being a major drawback, space being another. And of course while they almost never fail, they do occasionally, and will again. And those failures are utterly catastrophic, and it'd hard to convince a community to welcome a nuclear plant, and if the community doesn't want it then it can't or shouldn't be forced onto them.
They also represent tactical strike sites in time of combat engagement. Big red X for a missile.
There are also significant environmental concerns, as we really have no good way to dispose of nuclear waste in a safe or efficient manner at this time.
It's likely that nuclear based energy is the future, but you need to discuss the bad with the good here or we are just going to end up at square one again. There are long term ramifications.