I am still aggravated at me that I did not try to get a tour of WIPP when they were building it.
The salt bed it is in is about a half-mile thick and 225 million years old IIRC.
There is also a nice usable Yucca Mtn site available. But much better for stuff to just sit all over the country according to the ecofreaks.
A geologist I know saw core from the Yucca Mtn site. The rocks there are intensely fractured. Fine if the area stays arid for 10,000 years, but climate does change (despite the current AGW BS). (Where I am sitting was under 1+km of ice just 12,000 years ago, for instance.)
I got to tour the Yucca Mtn mine in early 1980’s.
Solid rock from top to bottom, only politics prevented its use.
While the eco's are freaked, the prime mover behind scuttling Yucca Mountain was the dishonorable Sen. Harry Reid. It's a little close to Vegas and his cynical re-election calculations took priority over the nation's safety.