So it happened that we discorvered in Africa in 1972 a natural uranium reactor. That is a place where the uranium naturally has a fissile reaction. The reactor was active 2billion years ago.
The place wasn't harmful for human or nature, which means we know that putting nuclear wastes in the ground is safe forever. And thus there is no problem of waste other than properly dealing with it.
The other thing worth noting is that nuclear plants don't have to produce really nasty waste. Most/all existing nuclear power plants are either bomb factories, or derived from bomb factories. They were designed to make plutonium for nuclear weapons. There are FAR better designs available. Unfortunately, the research has been killed off. It will take a long time to rebuild the knowledge base.
On a side note, most coal power stations emit more radioactive material than nuclear power plants are allowed to. It's mixed into most coal reserves.
As for the waste, most "nuclear waste" isn't as bad as it first sounds. It's things like gloves or other rubbish that is slightly radioactive from contamination. The amount of hyper radioactive waste is quite low (and can actually be eaten as fuel by newer designs).
Unfortunately, nuclear has been delayed for too long. We no longer have time to use it as a backbone of combatting climate change. It will take too long to design and build the new plants, let alone get the skill base to do it well and fast.
Spent fuel rod reactors are well into development, and they will be able to use that waste to generate power and leave behind non-radioactive materials.