I've realized what the wheel does.
It's obviously for lowering the moderator rods into the reactor pile.
Being the new millenium, everything will be nuclear-powered. (Isaac Asimov, back in the 50's thought we'd have atomic ashtrays by now !!)
When you have a bit of intensive editing to do, you crank-up the reactor closer to criticality and get up a head of steam for the turbines.