Just went here a week ago, had a blast exploring the two largest buildings closest to the railroad tracks (excluding the silos unfortunately) and got to see the roofs of both. The massive furnace room has graffiti on the outside of the smokestack on the roof, I can't imagine how people felt walking over to that...
I'd avoid the southernmost rooms, someone seems to be living there.
To answer Mossybread, there are some empty rooms with lab tables and cabinets/desks but they've been thoroughly wrecked. Photos attatched: