Which regulatory limit is cited as the boundary for off-site exposure in emergency planning?

• A. 10 CFR 20
• B. US NUREG 0737
• C. 10 CFR 50.46
• D. NRC Regulatory Guide 1.206

Answer: (A)

The boundary for off-site exposure in emergency planning is tied to the public dose limit established in 10 CFR 20. This regulation sets the maximum radiation dose a member of the public may receive from licensed activities in a year, and emergency planning uses that limit to determine planning distances and protective actions. In practice, planning zones are sized so that projected doses at the boundary stay within these public-dose limits, ensuring protection for the general population. The other options relate to different aspects of nuclear safety: NUREG 0737 deals with emergency notifications, 10 CFR 50.46 sets ECCS criteria, and Regulatory Guide 1.206 provides guidance on implementing dose projections and protective actions but does not set the boundary itself.