"Dave Eadsforth" wrote ...
Jim Yanik wrote
Any deep mine that had a nuclear explosion nearby deep underground would
have it's shafts collapse,or become inaccessible,just as effective as
destroying the WMD itself. They might even flood.

At one point, it was feared that an exploding nuke could send a stream
of VERY hot gasses along tunnels, thus spoiling everyone's day.
However, later modelling (and maybe even testing) revealed that an
underground nuclear explosion in an area containing shafts and tunnels
tends to crush them flat, thus sealing them and saving the rest of the
complex further damage. So, the lesson appeared to be; don't build
caverns, stick to tunnels and shafts.

That's interesting. Do you have a cite for that? During the underground test
era, in one test the blast doors failed. During a UGT, explosive-powered
doors located a short distance from the bomb chamber close after the prompt
radiation pulse drops off (a few hundred nanoseconds) and before the blast
wave arrives, to preserve the down-hole equipment. In one test, the doors
failed and the VERY hot gasses (and lots of fission fragments) both melted
and contaminated the equipment in the test galleries quite far back from the
bomb chamber.

I still think that earth penetrating nuclear weapons is the triumph of "Wow,
a NUKE" thinking over the realistic limits of what a nuclear weapon can do.