Fire and explosions, whether internal to the installation or external (earthquake, lightning) are possible initiators of major accidents. Protective measures must therefore be provided to prevent a fire or an explosion from leading to disasters with very serious economic and human consequences.

The presence of radioactive sources in this sector is an additional element to take into account in the fire protection. The risk being that the fire increases to such point that the protection of radioactive sources decreases. These sources could also present additional risks during the evacuation of people and the firefighting activities.

Expertise in fire and explosion risks requires knowledge of the phenomenology of fire and explosions in order to assess the measures to be implemented to control those risks. Redundancy, degraded mode, earthquake resistance, aging to radiation are common concepts that must be perfectly mastered to validate a nuclear installation.