I wasn't aware of this until now. High-level waste has heat. Enough said.
ps. Dear People, I am sorry for the outburst. It is just that with all the years I have worked on this, and all the experiments, nobody ever thought to place high-level in limestone. I am glad that they have very creative people in their organization. Who would have thought up such a thing? They want to go with the Cobourg limestone which is the wonderful stuff in the old Wesleyville caverns. I would think that if they wanted to do the very first scientific work on limestone, they could drain the tunnels and test there. But I think that real work would spoil the party, so I know that won't happen.
This limestone wears two hats. You either have it very tight and highly stressed, or loose and fractured on top of a megathrust. It is full of those nasty invisible joints that got them at Niagara, and the thermal conductivity drops like a stone (ha!) when heated. As well as a very high thermal expansion. Such fun!