Document: NUREG-0800
Document ID: 03aed7b8-74fc-467b-b928-b25d9eb89a13
Document Type: srp
Title: PHYSICAL SECURITY — REVIEW OF PHYSICAL SECURITY SYSTEM
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1301/ML13010A109.pdf
Revision Date: 2023-06
Chapter: 13
Section ID: 13.6.2
CFR Part: 
CFR Title: 

Content:
of the NRC’s philosophy that is used to address uncertainty by using successive measures, including safety margin, to prevent and mitigate damage if a malfunction, accident, or natural caused event occurs at a nuclear facility. Defense-in-depth philosophy applies to measures against intentional acts as required by 10 CFR 73.55(b). The most common defense-in-depth measures apply concepts of redundancy, diversity, independences, and safety margin to enhance systems reliability. Defense-in- depth is achieved by providing multiple layers of protection, systems, and/or barriers to avoid or provide the capability to tolerate failures that would prevent the accomplishment of a function (i.e., provide reasonable or high assurance that activities involving SNM are not inimical to the common defense and security and do not constitute an unreasonable risk to the public health and safety). Redundancy is to achieve system reliability through the use of independent means of accomplishing needed function (i.e., ensuring no single failure results in loss of the intended function). Diversity and separation provide protection against dependent (common cause) failures of multiple means of accomplishing needed functions. Diversity is achieved by using different technologies, equipment, manufacturers, control logic, signals, and functions to provide a diverse way of accomplishing the intended security function. Independence is attained by physical separation and physical barriers, including electrical or motor force independence. The NRC’s philosophy applies to the designs of physical protection systems, which integrate engineered controls and administrative controls, to provide a high assurance of protection against the DBT for radiological sabotage. 2. 10 CFR 73.55(e): As it relates to the design of physical barrier systems, their uses, type, functions, and placement, to satisfy the capabilities for control and delay of access into the facility areas. The design descriptions