The occurrence and consequences of a significant number of accidents are either eliminated outright or reduced by the SCOR concept at the design level. The major safety systems are passive; they require no operator action or off-site assistance for a long period after an accident. Moreover, core and containment cooling is provided during a long period without AC power.

The inherent safety features incorporated in the SCOR design are: [46]

The SCOR design incorporates the following passive safety systems:

• Passive residual heat removal system on the primary circuit (RRP). Passive operation of this system is ensured simultaneously in the primary circuit, in the RRP loop, and in the ultimate heat sink; the RRP system has two types of heat sinks: water pool and air-cooling tower;

• No action regarding the steam line of the steam generator is needed to ensure decay heat removal[47];

• In the case of a blackout, natural convection in the primary circuit with 4 operating RRPs is sufficient to remove the decay heat (and to achieve zero reactivity via feedback due to the moderator reactivity coefficient in the case of a anticipated transient without scram (ATWS));

• A dedicated steam dump pool, located in the containment building, prevents radioactivity release into the atmosphere in the case of a steam generator tube rupture;

• Passive control of the containment pressure by pressure suppression in the case of a LOCA;

• In-vessel retention of corium achieved via reactor cavity flooding in the case of a hypothetical severe accident;

• Infinite autonomy with the air cooling tower heat sink;

• Prevention of hydrogen combustion by maintaining an inert atmosphere in the reactor vessel compartment;

• One of the shutdown systems is based on insertion of gravity driven control rods to the core (the actuation of this system is the same as in a standard PWR), see [IV-1].

More details about passive safety systems incorporated in the SCOR design are given below.