3. Design requirements

The design requirements aim to implement, during the construction of the plant, the defense-in-depth approach based on the three lines of defense: prevention, sectorization and control through countermeasures.

Our approach to fire safety is purely deterministic. It is based on the following two assumptions:

• the fire can start anywhere – which implies a single outbreak of fire;

• the fire may occur regardless of the plant's normal operating status (at power or shutdown), or in a post-accident situation.

The design process consists of two parts:

• design requirements ;

• the verification process.