The country is divided into a primary planning zone and a secondary planning zone.
Primary planning zone
The primary planning zone is measured from the Cattenom nuclear power station:
- to a 15 km radius in the event of evacuation;
- to a 25 km radius in the event that potassium iodide tablets need to be taken and the population needs to take shelter.
The primary planning zone is divided into three alarm sectors.
- Eastern Sector;
- Central Sector;
- Western Sector.
This division enables separate alarm sirens to be triggered depending on wind direction and how urgent it is that the protective measures be implemented.
The aim of this territorial division is to limit the alarm to the zones actually under threat.
In the event of an evacuation from the primary zone, the population will be forbidden access to this zone.
Secondary planning zone
The secondary planning zone starts at the boundary of the primary planning zone and covers the rest of the country.
The main towns within the secondary planning zone will house the reception centres required in the event of an evacuation.
It is also possible however that the population residing in the secondary zone will need to take shelter and potassium iodide tablets.