What does defense-in-depth embody in core protection?

What does defense-in-depth embody in core protection?

• A. Multiple overlapping safety layers provide redundancy and fallback options
• B. Relying solely on operator actions
• C. Eliminating safety features
• D. Reducing layers to simplify the system

Answer: (A)

Defense-in-depth means safety is built with several independent, overlapping layers that can act as backups to one another. Each layer provides protection or a fallback action, so if one layer fails or is bypassed, others still respond to keep the core safe. In core protection this includes automatic protection systems that trip the reactor when parameters exceed limits, diverse sensors and protection logic to avoid a single fault causing a misread, physical barriers and cooling systems, and procedures or operator actions as a last line of defense. The whole idea is redundancy and multiple chances to detect and mitigate abnormal conditions, not relying on a single feature or dropping safety layers.

Defense-in-depth means safety is built with several independent, overlapping layers that can act as backups to one another. Each layer provides protection or a fallback action, so if one layer fails or is bypassed, others still respond to keep the core safe. In core protection this includes automatic protection systems that trip the reactor when parameters exceed limits, diverse sensors and protection logic to avoid a single fault causing a misread, physical barriers and cooling systems, and procedures or operator actions as a last line of defense. The whole idea is redundancy and multiple chances to detect and mitigate abnormal conditions, not relying on a single feature or dropping safety layers.