Document: NUREG-0800
Document ID: 496a8650-7c3b-4111-a527-d49e2f61ae5c
Document Type: srp
Title: PHYSICAL SECURITY—COMBINED LICENSE AND OPERATING REACTORS
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1729/ML17291B265.pdf
Revision Date: 2023-06
Chapter: 13
Section ID: 13.6.1
CFR Part: 
CFR Title: 

Content:
nitoring and human factors for human-machine interfaces; (8) redundancy for protection against DBT characteristics affecting availability of security communications; (9) safety and security interfaces for impact on nuclear operations, safety, or emergency response; and (10) technical basis for and the specifications of the DBT characteristics that are protected. f) Defense-in-Depth Designs of Physical Security Systems and Operational Requirements (Security Response): The designs of physical security systems should address systems diversity, independence, and separation, for defense-in-depth to achieve a high assurance of intended security functions and must meet all specific prescriptive design criteria set forth in 10 CFR 73.55. Defense-in-depth is an element 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 13.6.1-22 Revision 2 – August 2018 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 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