A few notes about the school. Yes, there is a radioactive fridge in the kitchen. I don't even know why, I just remember that there was.

The Demonology classrooms probably still have a large residue of magic left in them.

There are still working nanites that will repair the school itself should it ever be damaged. 

The basement is not locked, but the entrance is hidden. That's where the bombs were made, at least sometimes.