The SWR-1000 is equipped with 4 emergency condensers having a maximum power of about 60 MW at a pressure of 7 MPa. The emergency condensers are horizontal tubes arranged between two collectors (see Fig. XI-3). Each bundle consists of 104 tubes arranged in four vertical levels. The tubes have a length of 10 m, an inner diameter of 38.7 mm, a wall thickness of 2.9 mm and are made of austenitic steel (design state 1998). The upper collector is connected via the feed line and the lower connector via the back line connected to the reactor pressure vessel. Both lines can not be blocked. The back line is equipped with an anti circulation loop to avoid the establishment of a stratified counter current flow during the normal operation.

Under normal operation conditions the water level in the core is above the level in the emergency condenser bundles. The water inside the tubes is entirely single phase and no heat transfer to the flooding pool takes place (Fig. XI-3 left side).

During an accident the water level in the core sinks below the bundle level of the condenser. The condenser tubes are filled with steam and the emergency condenser acts as a heat sink (Fig. XI-3 right side). In addition, owing to the pools’ elevation, the water in the core flooding pools is used for passive flooding of the reactor core following reactor pressure vessel depressurization in the event of a loss of coolant accident. For this function, spring-assisted check valves open the core flooding lines automatically. Passive core flooding serves as a diverse means of providing reactor pressure vessel coolant makeup which supplements the active core cooling systems.