Two-zone, small volume, high pressure containment. The containment is partitioned into two separate leak tight zones: LCZ the Lower Containment Zone, consisting of the reactor cavity below the RPV, and containing the RCP's mounted on the RPV bottom, and other equipment, not shown (e.g. shielding, instrumentation). Free volume of the LCZ is approx. 230 cubic meters. UCZ the Upper Containment Zone, comprising the region surrounding the upper part of the RPV and the two Steam Generator (SG) compartments. Free volume of the UCZ is at least 4500 cubic meters. The free volume in the lower part of the UCZ, that is, below the level of the RCS main piping connections, is approx. 700 cubic meters. Maximum pressure for both LCZ and UCZ is close to 20 bars. Four containment access openings include the containment dome above the RPV, and access ports for the LCZ (reactor cavity), and for the SG compartments.