DBA are accidents that a Nuclear Power Plant must be designed and built to withstand without loss to which of the following?

• A. All electrical systems
• B. The external power supply only
• C. The cooling water system only
• D. The systems, structures, and components needed to ensure public health and safety

Answer: (D)

DBAs define the accidents a plant must survive without losing the safety functions that protect public health and safety. That means the design must keep all safety-critical systems, structures, and components functioning so cooling, containment, power to safety systems, instrumentation, and other protective actions can operate to limit radiological releases. It isn’t about any single subsystem like just electrical power or just cooling; it’s about preserving the entire set of safety functions necessary to keep people and the environment safe during credible accidents. The narrower options fail because they point to only one aspect rather than all essential safety-related functions.