I went through the console command
Prid 000b877e (Brandis ref ID)
Moveto player
This makes him appear in the bunker and he moves to the position where he is supposed to be.
Then the problem is that there is no way to interact with him.
I've tried deactivating/activating the ai via
Clicking on him during console mode so that his "code" appears then typing "tai" doesn't seem to do the trick.
Any ideas...?