Which of the following best describes how radiological alarms are used in the plant?

• A. They are used to measure ambient temperature in the plant.
• B. They are used to calibrate radiation equipment.
• C. They are used to sample air in the plant and trigger alarms when radiological levels rise.
• D. They have no role in safety monitoring.

Answer: (C)

Alarms in a radiological plant are designed to monitor airborne radioactivity and provide an immediate warning when contamination levels rise. They continuously sample air from work areas or ventilation paths and use detectors to measure radioactivity. If the readings exceed preset limits, the alarm sounds and the system can trigger protective actions, such as pausing operations, isolating the area, or activating filtration and containment. This setup gives workers time to evacuate or implement decontamination before exposure becomes a risk.

These alarms aren’t intended to measure ambient temperature, nor are they used to calibrate radiation equipment. Calibration relies on known radiation sources and standards, not on alarm signals. And while they’re not the only safety tools, they do play a direct and essential role in safety monitoring by providing early detection of airborne radiological levels.