Chris grew up in Vault 34 and was a vault engineer. He was often sent to work on the reactor, which he believed would turn him into a ghoul. Eventually his hair began falling out due to natural reasons, but Chris insisted he was becoming a ghoul and subsequently left the Vault. This could have caused the reactor in Vault 34 to become unstable and leak the dangerous radiation, turning all the residents into ghouls.
Boomers wikia info:
In 2231, the group of dissidents from Vault 34 struck out on their own and began using Nellis as a temporary base.
Vault 34 overseer fragments:
... riots begin soon after; during the peak of the violence the group calling for free access to the armory stormed the Vault's exit and left. The door was sealed after them and additional guards were stationed at the exit; this proved to be a grave mistake. With the additional guards at the exit there were fewer to patrol the halls, none of them were prepared for the group that ambushed the armory. The guards were able to defend their position, but not before the damage was done, during the fight one of the reactors cooling vents was damaged.
...fighting settled slightly following the announcement of the damage to the reactor before panic overtook the vault's residents. The technicians struggled to repair the damage to the reactor and main computer systems. We learned too late that as part of an automatic safety protocol the reactor had been reconfigured to use alternative pipe lines for its cooling systems, unfortunately with the damage to the mainframe the system was unable to detect the structural damage to the vault. Radioactive gasses pumped through the broken pipes and irradiated the vault. On top of it all, we cannot open the vault's main door. All systems appear to be on autopilot and manual override functions have been disabled. We'll just have to hope we can survive long enough for the door to open automatically...
So... Haversam is either a mutant with a really really slow aging process, lying or inconsistency?