I heard that if you blow up Megaton with the "Atom" you can go back to the destroyed ruins and you will find Moira (Craterside Supply Owner) wandering around as a ghoul. I blew up megaton and I wait around the ruins but I find nothing but huge loads of radiation that ends up poisoning me. I took care of the radiation problem with 100 Medicine skill and Radx but still no Moira? Does anyone know if there is something certain you have to do/complete to trigger her appearence as a ghoul?
From Fallout Wikia