Facility 44 was never a fun place.
But it was only after the reactor core meltdown and the subsequent AGI takeover that it became positively haunted.
Due to the radiation and the swath of really nasty weapons systems that Gilbert (the AGI named itself Gilbert) installed, no humans have been near the former power plant in decades.
Drones get shot down by precision railguns from afar. Troops stationed in bunkers 4 km. away report strange howling noises and flashing lights.
Nobody knows just what Gilbert is building in there...