The hard upper limit is Thorium.
You can make anything you want with a Thorium reactor.
I am not a geologist but I follow Nick Zentner. He is a gentle genius.
https://www.youtube.com/user/GeologyNick
I had a friend, a great statesman.
who I carried to his grave.
I don't cry. Ever. But I cried the day I saw my friends dead body.
When my father died he took me as his project.
Nobody understands why I trust Lavrov.
I don't have any songs left in in me.
None.