Which type of radiation has penetrating-high, shielding by water, lead, steel, concrete, hazard dose to entire body if exposed, found only in or near operation reactor?

• A. Beta
• B. Gamma
• C. Neutron
• D. TEDE

Answer: (C)

Neutron radiation is highly penetrating and requires hydrogen‑rich shielding, such as water or concrete, to slow and absorb them effectively. In a reactor environment, neutrons are produced by fission and can stream out from the core, delivering energy to tissues throughout the body if exposure occurs, which makes the whole‑body dose a primary concern. Shielding with materials like water or concrete (and, in layered shielding, combinations including other materials) is a standard approach because hydrogenous substances are particularly good at slowing neutrons and reducing their flux. Beta radiation is much less penetrating and can be stopped by light shielding or skin; gamma radiation is also highly penetrating and is typically shielded best by dense metals like lead, but it is not unique to reactor operation. TEDE is a dose measure, not a type of radiation.