2/n
So how the reactor works (the Holy Lead is on interleaving metal discs that are turned into close proximity with a big wheel on the front of the furnace) is explained.
How the Njemmish at a steam-engine tech level got hold of what we can only assume is enriched uranium, without even really understanding the physics of how it works (Storvin explicily says so) is NOT explained. At least, not until The Trovador, if I ever get that finished.