Yan Bibiyan...I was thinking of the exact same thing. I remember seeing something on Discovery (?) a few years ago that tracked what would happen if all humans suddenly vanished from the Earth. Once the power grid went down and the backup generators ran out of gas, the spent fuel rods would trigger a nuclear meltdown...all within mere days of the power grid going down. The program said that there are something like 300+ reactors in mainland Europe alone. So basically within days, all of Europe would be a nuclear wasteland.
That is, unless there was divine intervention...............
I've mentioned this fact on occassion to my Dub friends and they shrug and say "...well, who knows...".