How long should you remain on the deck after a nuclear explosion?

Remaining on the deck for 90 seconds after a nuclear explosion is recommended due to the need to avoid immediate radiation exposure from the initial blast and to assess the situation for potential fallout. During this time, you are allowing for the initial shockwave and thermal pulse to dissipate, as well as granting valuable seconds for any airborne radioactive material, which tends to be present shortly after the explosion, to settle or disperse.

After an explosion, the most intense and immediate radiation effects occur right after the detonation; thus, it is crucial to stay indoors or remain in a protected position during this vital time window. By waiting 90 seconds, you reduce the risk of exposure to harmful radiation from both the blast and initial fallout. This duration is based on protocols designed to maximize safety during the high-risk period immediately following such a catastrophic event.

In contrast, other durations proposed in the choices might not provide sufficient time for safety measures to take effect. Some may be too short, potentially exposing individuals to dangerous doses of radiation, while a longer time frame may not be practical in a real-world emergency situation when evacuation is needed.