Containment passive-cooling design concepts

A containment is proposed for a high rating PWR (1300 MW_e) that makes it possible to reject sufficient heat to maintain internal conditions below design limits during any postulated design basis accident. The proposed containment thus eliminates the need to employ active features for containment cooling, and conformes to guidelines set forth for passive reactor systems. EPRI, 1987] The design is based in part on a currently operating PWR containment (Waterford 3). A series of modifications and additions are necessary to make passive heat rejection possible. The modifications are an increase in free volume and primary shell surface area. The additions are the perforation of the secondary containment structure to form an air-convection annulus, and allow the submersion of the lower part of the containment into an external pool; an internal pool increases in-containment heat storage. Proposed features are evaluated analytically, computationally and, where possible and necessary, experimentally. The proposed containment is shown to remain below current regulatory limits for the design-basis postulated loss of coolant accident.