200,000 years is not much on geological timescales. Here's one example of a place with very stable geology: https://en.wikipedia.org/wiki/Canadian_Shield

The other main thing to remember when burying nuclear waste is that it's important to keep it away from aquifers and generally any flow of water under the ground. Obviously you'd probably want to seal it in waterproof containers anyway, but it's better to not have to rely on the container staying intact over long spans of time.