What type of radiation occurs within the first 90 seconds of a blast?

The type of radiation that occurs within the first 90 seconds of a blast is classified as initial radiation. This radiation is a result of the immediate energy released during a nuclear explosion, which includes a combination of gamma rays and neutron radiation. Initial radiation has a significant impact on the environment and has the potential to cause acute radiation sickness in individuals exposed without adequate protection.

Understanding this concept is crucial for military personnel and first responders, as it highlights the immediate dangers following a nuclear detonation. Initial radiation is distinct from other types of radiation that may emerge later, such as residual radiation, which persists in the environment and can have long-term health effects, or thermal radiation, which causes intense heat and can lead to burns and fires. By recognizing the specific characteristics and timing of initial radiation, individuals can make informed decisions about protective measures and evacuations in the event of a nuclear explosion.