Moddern reactor designs are tolerant to Backpacker's scenarios. They are designed that on loss of the 'supporting systems' they simply slowly shutdown.
This was also a design feature of the Advance Gas Reactors built in the UK - convection was enough to keep them from going critical.
The water cooled designs from the 60s are much more problematic and often need a massive dump of water or continued cooling. But no one - apart from perhaps the Russians, North Koreans and Iranians, would even think of building that type of reactor.
There is more rubbish spouted about the risks of nuclear power than there is from 'Wee Eck' and the SNP about how Scotland will e energy sufficent from windmills. A modern nuclear plant is reliable (which is really useful on a winter's day), safe and produces precious waste. A windmill relies upon an unreliable resource and is only cost effective if the grotesque subsidy is paid. Even better there is now some evidence that windmills alter the local climate...........