Please elaborate; I'm intrigued...

A Faraday cage will protect against an EM pulse? http://en.wikipedia.org/wiki/Faraday_cage

RepRap is a self-reproducible 3D printer? http://reprap.org/wiki/RepRap

And so with the RepRap (and some power source/converter) inside a faraday cage (with other physical protections as well), you're saying that this is the ultimate backup system for worst case scenarios? Do you have any links to provide more information about such a setup?