There are of course ways to shield from that (as illustrated by spacecraft and common military electronics), but nuclear station damage control robotics is perhaps too niche application to be implemented.
FNAL, BNL, CERN ...and KEK all use radhard electronics (obviously not everywhere), admittedly on the fringes of your illustrating application areas. Combined, that is already quite a large area, so to my mind parts for tough (damage) control robotics isn't such a niche.
But true, small production runs and spares is a real issue (actually, by the time they are really used, they are already obsolete -- but this is why you have upgrade plans :).
As I understand it, canadian CANDU reactors use a robotic system to perform online refueling. They also use heavy water as a moderator, and burn unrefined uranium / [can] spent fuel from other reactors pretty impressive machines I think.
