AT 845 AN UNPLANNED EXPLOSION OCCURRED IN THE COAL SILO DUST COLLECTOR. THERE WERE NO INJURIES. DAMAGE TO EQUIPMENT INCLUDED. A ACCESS DOOR WAS BLOWN OFF OF THE COAL SCREW AND DAMAGED A HANDRA IL WHEN IT LANDED ON A LOWER LEVEL ROOF: THE BAGS OF THE DUST COLLECTOR WERE BURNED AS WERE SEVERAL CARDBOARD BOXES STORED NEAR THE DUST COLLECTOR.