Defense in Depth
Defense in depth employs multiple independent barriers and safety layers to prevent and mitigate accidents.
Includes design, operation, systems, structures, and emergency procedures. NRC requires 5 levels: prevention, control, defect management, accident management, mitigation. Applied since 1950s.
Why it matters now
Defense in depth underpins SMR licensing and investor confidence in 2025-2026 amid public scrutiny.
Related reactors
AP1000