This is my first post and its not even mine; lame, I know.
I found this on bookofjoe and have no idea If it's been posted before. Anyways, photos are amazing and you should definitely check them out. References and complete history are here.
Caption: 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.
BTW; GREAT community. :)