Delayed nuclear radiation arises from the decay of fission fragments after the initial fission event.

Delayed nuclear radiation arises from the decay of fission fragments after the initial fission event.

• A. Prompt neutrons from fission
• B. Delayed nuclear radiation
• C. Reactor heat without radiation
• D. Neutrinos from fusion

Answer: (B)

Delayed nuclear radiation comes from the decay of fission fragments that remain unstable after the fission event. When fission occurs, a wide variety of fragments are produced, and most of them are radioactive with different half-lives. As these fragments beta-decay (often emitting gamma rays) over timescales from milliseconds to hours, radiation is released long after the initial fission has happened. This is distinct from prompt radiation, which is emitted immediately during fission, such as prompt neutrons and prompt gamma rays. The other choices don’t fit: prompt neutrons are not delayed, the idea of reactor heat without radiation ignores the radiation from decay, and neutrinos from fusion relate to a different process altogether.

Delayed nuclear radiation comes from the decay of fission fragments that remain unstable after the fission event. When fission occurs, a wide variety of fragments are produced, and most of them are radioactive with different half-lives. As these fragments beta-decay (often emitting gamma rays) over timescales from milliseconds to hours, radiation is released long after the initial fission has happened. This is distinct from prompt radiation, which is emitted immediately during fission, such as prompt neutrons and prompt gamma rays. The other choices don’t fit: prompt neutrons are not delayed, the idea of reactor heat without radiation ignores the radiation from decay, and neutrinos from fusion relate to a different process altogether.