Cubit Store. 3 for 1500
As the nuke is placed, anything on and above its terrain level will be destroyed permanently. It takes 10 seconds to explode, and will not destroy any Doorways on its path. If a doorway is affected, it will be automatically placed on the nearest block underneath.
It is also important to remember that the use of a nuke deletes items, and does not make them pick-able.
Here's a simple graphical representation:
How to obtain
Nukes can be bought from the Cubit Store in packs of 3. Each pack costs 1500