[GSlob]

And how deep underground are these facilities? A bunker buster could destroy the entrance, or hit a ventilation shaft, but how much damage would it do to the body of a facility 200-300ft below the surface?
Here is a theoretical question: normally the nukes go supercritical in a spherical configuration, if only for the reasons of materials economy. What would happen if the supercriticality is achieved in a shaped charge geometry [yes, it would take more uranium]? Would it be possible to have a directed nuclear explosion for enhanced penetration?

[Paul_Denton]

The US has had linear geometry implosion for years but not for the munroe effect (linear implosion cannot do it to my knwledge). Linear implosion is designed to make the warheard diameter small enough to fit inside 155mm artillery shells.

[cpdiii]

A shaped charge depends on the shaped explosive turning a metal (normally copper) into a hyper velocity stream of plasma. I can not see this working on a fission or fusion bomb. Its power is derived from gamma rays and hard xrays that heat up the surrounding enviroment. Do we have a physicist around here that can comment?