The great northern coast of Russia is inside the Arctic Circle, and the shoreline is hundreds of miles from civilisation almost the whole way along. Lighthouses were required for the coast, because it’s a handy passage but it spends a hundred days of the year in near-permanent night. The problems were that they’d be miles from anywhere, and couldn’t realistically be supplied or crewed.
So the Russians erected autonomous nuclear-powered lighthouses. Which worked great, until the collapse of the Soviet Union. In fact, they probably would have been fine after that, if people hadn’t looted them for copper and anything else that looked like it wasn’t nailed down too hard. Including, apparently, reactor shielding. So many of these great polar nuclear lighthouses are now radioactive deadzones.
This is satisfyingly apocalyptic for me. Mmmmmmm.