You cant dismantle a plant that still generates residual heat while a used fuel pool is on fire nearby. Its just too dangerous a place for humans to be. What should they have done? Sent Asimo?
Just note that robots don't work either, because particle radiation has a nasty way of flipping bits stored in memory. In the presence of a strong beta ray source, you can treat sram and dram as good sources of truly random data. :)
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.