Nuclear fuel in the reactor cores melted after the magnitude 9.0 earthquake and tsunami in March 2011 caused the Fukushima Daiichi nuclear plant's cooling systems to fail
Without the addon there was a robot companion that would refuse to go in, just like Fawkes does before you get the dlc. After you get the dlc both companions will go in, and be fine afterwards, because radiation doesn’t affect them.
Much like Fawkes the robot companion said some BS about not robbing you of your destiny before you install that particular dlc.
Robot clearly never watched the ending of Fallout 3 about letting the humans do it instead.
Human Robots
Or let a super mutant do it for you if you’ve bought the add-on
Without the addon there was a robot companion that would refuse to go in, just like Fawkes does before you get the dlc. After you get the dlc both companions will go in, and be fine afterwards, because radiation doesn’t affect them.
Much like Fawkes the robot companion said some BS about not robbing you of your destiny before you install that particular dlc.