The negative fuel temperature coefficient is an example of which type of safety feature?

• A. Inherent safety feature
• B. Active safety feature
• C. Redundant safety feature
• D. Diverse safety feature

Answer: (A)

The property being tested is the idea that some safety features are built into the system’s physics so they work automatically without external action. A negative fuel temperature coefficient means that as the fuel temperature rises, reactivity decreases. This automatic, self-regulating behavior tends to limit power growth during overheating, providing a passive check on the reactor’s response.

Because this effect arises from the fuel material and core design itself, it operates without relying on sensors, actuators, or operator actions, which is why it’s considered inherent. It isn’t about duplicating systems (redundant) or using different approaches to safety (diverse), nor does it require active intervention to function (active).