>For instance, that nuclear waste storage facility we’re building at Yucca mountain was put there based on estimates that that site has been geologically stable for millions of years.
I see. Though the past is not necessarily an indication of the future, all it would take is one [unexpected] catastrophic event as in Mt St Helen’s.
Yes, it would. Yucca Mountain was formed by a supervolcano. According to the (old Earth theory) scientists, that volcano has been extinct for, I believe, about 12 million years. If the YEC theories are correct, that volcano would have been active within the last 6 thousand years.