Closed doors in North-Prison

[dvow]

I think these are all things that change either on each play through or when you die.

Wrong.

The first door in the prison can be opened with the rock chipper thing, with the hammer. If you went down the hole before opening it, you can't get back. There is nothing really important in that room though. There's just an oil barrel and a few supplies.
And none of the doors with fine locks can be opened. The wooden door that's sealed is also where the monster spawns. There are numerous doors like these in the game--think of the one in the storage room.