EPRI Core Protection NANTeL Practice Test 2026 – Complete Exam Prep

Defense-in-depth means building safety through multiple, independent layers so that a failure in one barrier doesn’t lead to an unsafe condition. The best approach for a utility is to design to prevent accidents, while also recognizing that accidents can occur and preparing to cope with them. That means providing proven capability to handle the range of worst-case accidents, so the plant can maintain safety even under severe events. This combination—preventing events, assuming failures can happen, and ensuring robust, tested responses to the most challenging scenarios—embodies the layered protection mindset.

The other approaches miss this balance. Focusing solely on maximizing production ignores safety; assuming accidents won’t occur denies the reality that failures can happen; and offering no plan for worst-case fails to provide the necessary resilience backbone.