What are the three plant boundaries in a nuclear facility?

• A. Public Area, Protected Area, and Vital Area.
• B. Owner Controlled Area, Public Area, and Vital Area.
• C. Owner Controlled Area, Protected Area, and Vital Area.
• D. Public Area, Owner Controlled Area, and Critical Area.

Answer: (C)

Access control in a nuclear facility is built on nested security zones that define who can go where. The outer layer is the Owner Controlled Area, where basic access is managed by the facility owner. Moving inward, the Protected Area adds stronger controls and requires additional authorization. The innermost layer is the Vital Area, which contains safety-critical systems and is therefore the most tightly restricted. These three boundaries together form the plant’s security envelope, and reaching the Vital Area means you must be cleared and escorted through the surrounding areas. The other terms shown aren’t used together as the standard plant boundary set in this framework, since Public Area sits outside the plant’s boundary structure and Critical Area isn’t the defined terminology here.