Description of the containment for a stationary pressurized water reactor

The function of the containment is to prevent the inadvertent release of radioactive fission products from the reactor coolant system to the atmosphere and to provide biological shielding during both normal and accident operation. Basically three different containment concepts 1) the dry containment, 2) the subatmospheric containment, and 3) the ice condenser containment, have been developed, based on how the accident energy release from the reactor coolant system is controlled. The containment structure can be either 1) reinforced concrets with inside liner, 2) prestressed concrete with inside, or 3) full steel cylinder or steel sphere with separate concrete shield. The size of the containment is largely dictated by the required net free volume, that satisfies the energy release criteria due to the design basic accident. The design and construction methods applied to this structure guarantee that the containment will carry out its safety function. This was proven by the Three Mile Island accident. (author)