This is a place I'm planing to visit next time I'm in Poland. I saw this on the History Channel last month, not sure if its tourist accessible. You might be able to see the the outside test facility but the Mine I have no idea.
Contact Igor Witkowski
He gave the tour to the History Channel guys. He would be the guy to ask. Let us know how it went.
Wenceslas mine is in Poland
Poland as far as I know, that's what they said when they were filming there.