  Blaidd Drwg (Welsh for Bad Wolf) was the name of a nuclear power plant, planned to be built in central Cardiff. Behind the plans was Blon Fel-Fotch Passameer-Day Slitheen, posing as the new Lord Mayor of Cardiff, Margaret Blaine. The plans were to build the power plant on top of the Cardiff rift. The power plant would later have a meltdown, causing the rift to open. According to Blaine she chose the name at random, thinking it sounded good. (DW: Boom Town). This is the first time the doctor notices that the phrase seems to be wherever they go.
The power station was kept on after this and was turned into a functioning station. (TW: Everything Changes) Guy Wildman worked here and used his connections to steal 6 uranium cores for the Bruydac. (TWM: Another Life)
