Inherent safety features are features incorporated into the design and are a result of basic physics, such as the

• A. They require active operation of equipment
• B. Negative fuel temperature coefficient
• C. They are always external to the design
• D. They depend on building new components during operation

Answer: (B)

Inherent safety features come from how the reactor naturally responds to changes due to basic physical properties, so they act without needing any external action. A negative fuel temperature coefficient is a prime example: when the fuel gets hotter, the reactivity decreases, which slows or stops the power rise on its own. This self-regulating behavior is built into the physics of the fuel and reactor design, making it a core demonstration of inherent safety.

The other options describe mechanisms that require active intervention, or involve external additions, or rely on changing the system during operation. Those are not intrinsic, physics-based safety features, whereas the negative temperature coefficient directly embodies that passive, physics-driven response.