What would happen if humans disappeared?

[NorthernRaider]

TH most of the reactors would not melt down mate, some probably will be all of the better designed ones ave huge fail safe systems. I think they are called SCRAM systems and they fail SAFE IE the Carbon rods used to control the reaction automatically get rammed home if the power supplies fail or the water temp rises above a safe limit, so they will still be radioactive for decades in the reactor cores but you wont get a Chernobyl or Three Mile Island event. Still would not want to live near one though!