Soviet Russia needed lighthouses on their uninhabited Northern Coast, so they built automated lighthouses powered by small nuclear reactors.
During the days of the former Soviet Union, the government decided to build autonomous lighthouses on the Northern coast of the country. Often hundreds of miles from the nearest villages and towns, they needed an independent power source. After reviewing different ideas on how to make them work for years without service and any external power supply, Soviet engineers decided to implement atomic energy to power up those structures.
So, special lightweight small atomic reactors were produced in limited series to be delivered to the Polar Circle lands and to be installed on the lighthouses. Those small reactors could work in the independent mode for years and didn’t require any human interference, so it was very handy in a situation like this. It was a kind of robot-lighthouse that counted itself the time of the year and the length of the daylight, turned on its lights when it was needed, sent radio signals to near by ships to warn them on their journey.
Then, after the collapse of the Soviet Union, the unattended automatic lighthouses did it a job for some time, but after some time they collapsed too. Mostly as a result of the hunt for metals like copper and other stuff performed by the looters. They didn’t care or maybe even didn’t know the meaning of the “Radioactive Danger” sign and ignored them, breaking in and destroying the equipment. It sounds creepy but they broke into the reactors too causing all the structures to become radioactively polluted.