Radiation protection: in a power reactor, the biological shield is provided primarily to protect which group from radiation exposure?

Introduction / Context:
A biological shield is a mass of material (e.g., heavy concrete, water tanks, steel) designed to attenuate neutron and gamma radiation to safe levels outside the reactor core region. Its primary purpose is occupational safety.

Given Data / Assumptions:

• Shield design focuses on protecting people working around the reactor.
• Materials are selected for attenuation of both fast/thermal neutrons and photons.

Concept / Approach:
While fuel elements and structural walls must also withstand radiation, the explicit term ”biological” emphasizes protection of living beings—namely operating and maintenance personnel, and the surrounding public. Shielding reduces dose rates in accessible areas to below regulatory limits.

Step-by-Step Solution:

Verification / Alternative check:
Facility layouts and ALARA (As Low As Reasonably Achievable) practices prioritize dose reduction for workers through fixed shields and distance/time controls.

Why Other Options Are Wrong:

• Fuel elements: are the source; shielding is designed around them.
• Reactor building walls/control rods: not the principal target of biological dose limitation.
• None of these: incorrect because personnel protection is the aim.

Common Pitfalls:
Misreading ”biological” as structural; overlooking neutron vs gamma attenuation requirements.

Final Answer:
Operating personnel