Which statement best describes a passive safety system?

• A. It operates without requiring external power input, using gravity and natural forces to provide safety
• B. It requires continuous electrical power input to function
• C. It depends entirely on operator actions
• D. It is designed to be faster than active systems

Answer: (A)

Passive safety systems rely on natural forces and do not require external power input. They are designed to act automatically using gravity, natural circulation, phase changes, or stored energy released without needing electrical power or active control. This makes them reliable even in loss-of-power situations, which is the defining feature of a passive system. The statement that best describes this is the one that emphasizes operating without external power and using gravity and natural forces to provide safety. The other descriptions describe active power requirements, operator dependence, or a speed claim that isn’t the defining characteristic of passive safety.