In a radiation safety program, which is not a primary control?

• A. Shielding
• B. Time
• C. Distance
• D. Temperature control

Answer: (D)

The question tests understanding of the main controls used to reduce radiation exposure. The primary methods are shielding the source, maximizing distance from the source, and limiting the time spent near it. Shielding blocks or attenuates radiation, distance leverages the inverse-square law to lower intensity with separation, and reducing time directly cuts the dose proportional to exposure duration.

Temperature control does not affect the radiation field itself; it governs environmental or equipment conditions but does not reduce dose from the radiation source. Therefore, temperature control is not a primary radiation protection measure.