I decieded to follow in Dad's footsteps and do the noble heroic thing by sacrificing myself rather than forcing Sarah Lyons to die doing the job.
I had Fawkes with me and somehow he got into the chamber with me but I thought, meh, that's in keeping with the game. Anyway, after entering the code and watching the screen fade out, it seems that somehow my Lone wanderer survived and lived to fight another day, according to the narration speech given by Ron Pearlman.
My theory is this:
if Fawkes was with you in the chamber, and because he's reletively immune to high levels of radiation, he somehow manages to get you out of the chamber and saves your life.
Perhaps this is something the developers may have secretly factored in hmm? A way to save Project Purity and live to tell the tale!
Or perhaps its just a bug?
For my 2 caps worth, Tal Aureliano lived and is eagerly awaiting the next installment of adventures in the wastelands!