Did it already happen?
Item – ENE-News article “Heaving of bottom” may have taken place below broken bolts”
A comment to the article is relevant to Bayou Corne –
“the salt, though like rock, is fluid. The rate of creep is slow but has a high variability to it. The salt is compressed from the weight above, and this pressure is manifested in all directions, sort of like when you pressurize water. So when you hollow it out, there is tremendous pressure, like a truck pressing in on each square inch. This enormous pressure slowly fills the void from all directions.
Imagine that there is the gas/atmosphere that also gets pressurized and would surely be escaping through the smallest egress. Explosive gas at high pressure…this is one reason they back fill and plug with concrete as they go.
The reason there are salt dome formations is because the salt is less dense compared to surrounding rock and it slowly “floats” toward the surface in balloon like shapes. This would eventually…eons… bring the waste with it to the surface, if it could burst through cap rock and whatever.”
ALSO – Nuke Pro has a good summary of the situation in New Mexico – WIPP A Nuclear Disaster In 2014 In New Mexico and How to Understand It