My favorite is mixed design - nuclear fusion core which itself may be even a bit net energy negative (and thus much more realistic in the near future) and which main purpose is to generate neutrons to burn pretty much anything "heavy" and cheap. Turn the power to the core off - the thing just stops.
http://en.wikipedia.org/wiki/Waste_Isolation_Pilot_Plant http://en.wikipedia.org/wiki/Yucca_Mountain_nuclear_waste_re...
Nuclear power is safe, intrinsically. Nuclear waste is devastation waiting to happen (if not now, in the future).
If you take the waste out of a thorium cycle reactor (ie. no fission products with half lifes > 100 hears), burn it down until there is basically nothing left then turn it into glass and stick it underneath solid granite in the middle of the worlds most geologically stable tectonic plate then no. It's not exactly devistation.