A circular area (less zone I) determined by using minimum safe distance II as the radius and the desired ground zero as the center in which all personnel require maximum protection. Maximum protection denotes that armed forces personnel are in buttoned up tanks or crouched in foxholes with improvised overhead shielding.
ZONE II (NUCLEAR)
Meaning of ZONE II (NUCLEAR) in English
DOD English dictionary of military terms. Английский словарь военных терминов DOD. 2012