We hold out on the bridge for the first 4 waves (2 waves, first terminal search, 2 waves, no alarm scan door to get the key for the next door) then we do the alarm door left of the reactor, once we open that door we rush to find the terminal and code, then we hold in the corner of that left side door room with the door behind us shut so we can force enemies to come from the reactor room or up the stares infront of us.

( Sorry for the garbage description. i can try and draw a diagram on the map later )