Airlock doors provide airtight joints that prevent the leakage of air from Reactor Containment Building (RCB) to the outside atmosphere.
There are three main types of air locks:
Each of the above stated doors are 2 in Nos. (6 in total), one at the entry outside the airlock chamber and one at the entry from the airlock chamber into the RCB. These are interlocked in such a way that only one door can operate at a time & each door can be operated only when the other is in closed condition.