Which statement is true about safety system functionality?

• A. Door interlock only must be functional; others may be optional
• B. Audiovisual monitors alone satisfy safety requirements
• C. All listed safety features must be functional (door interlock, door closing safety system, audiovisual monitors, radiation area monitor, and beam-on indicator)
• D. The beam-on indicator is optional

Answer: (C)

All of the safety components work as layered protections to prevent accidental exposure. The door interlock stops you from opening the treatment door while the beam could be on, the door closing safety system makes sure the door is properly shut before any radiation can occur, audiovisual monitors provide real-time cues and fault awareness to the operator, the radiation area monitor watches for dangerous radiation levels in the area and can trigger alarms or shutdowns, and the beam-on indicator clearly shows when the beam is active. If any one of these parts isn’t functional, there’s a gap in protection that could allow exposure or entry when it shouldn’t happen. That’s why every listed safety feature needs to be functional. Options suggesting only some features are required or that audiovisual monitors alone suffice would leave the system vulnerable.