This is mindboggling (and the uses of it even more so)!
"Nuclear subterrenes work by melting their way through the rock and
soil, actually vitrifying it as they go, and leaving a neat, solidly
glass-lined tunnel behind them.
The heat is supplied by a compact nuclear reactor that circulates
liquid lithium from the reactor core to the tunnel face, where it
melts the rock. In the process of melting the rock the lithium loses
some of its heat. It is then circulated back along the exterior of
the tunneling machine to help cool the vitrified rock as the
tunneling machine forces its way forward. The cooled lithium then
circulates back to the reactor where the whole cycle starts over. In
this way the nuclear subterrene slices through the rock like a
nuclear powered, 2,000 degree Fahrenheit (1,100 Celsius) earthworm,
boring its way deep underground. " (source)
It very much brought to mind this:
“Then
the kings of the earth and the great men and the generals and the rich
and the strong, and every one, slave and free, hid in the caves and
among the rocks of the mountains, 16 calling
to the mountains and rocks, 'Fall on us and hide us from the face of
him who is seated on the throne, and from the wrath of the Lamb; 17 for the great day of their wrath has come, and who can stand before it?' ” (Revelation 6)
