Activation products are created when reactor materials are exposed to neutron irradiation.

• A. True
• B. False
• C. Only when the reactor is operating at full power
• D. Only during maintenance

Answer: (A)

Activation products form when materials are exposed to neutron irradiation because neutrons interact with nuclei and can be captured, turning stable nuclei into radioactive isotopes. In a reactor, there is a neutron field whenever the reactor is generating neutrons, and materials in the core and surrounding structures accumulate these products over time. This means activation can occur at any operating level, not only at full power; even during startup, cooldown, or low-power operation, a sufficient neutron flux can activate materials. Activation is not limited to maintenance periods; activated components can be present due to irradiation during operation, which is why handling such parts is a radiological concern during maintenance. Once formed, these activation products decay over time, emitting radiation with characteristic half-lives. So the statement is true because neutron irradiation creates activation products.