Document: NUREG-0800
Document ID: 96afb1d6-6ce9-41e4-b4ec-1fc7747bc0b2
Document Type: srp
Title: Revision 8 – January 2021
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML2033/ML20339A647.pdf
Revision Date: 2023-05
Chapter: 7
Section ID: 7
CFR Part: 
CFR Title: 

Content:
nd Regulatory Affairs (3150-0011, 3150-0151), Attn: Desk Officer for the Nuclear Regulatory Commission, 725 17th Street, NW Washington, DC 20503; e-mail: oira_submission@omb.eop.gov. Public Protection Notification The NRC may not conduct or sponsor, and a person is not required to respond to, a collection of information unless the document requesting or requiring the collection displays a currently valid OMB control number. ____________________________________________________________________________ BTP 7-19-38 Revision 8 – January 2021 BTP Section 7-19 Description of Changes GUIDANCE FOR EVALUATION OF DEFENSE IN DEPTH AND DIVERSITY TO ADDRESS COMMON-CAUSE FAILURE DUE TO LATENT DESIGN DEFECTS IN DIGITAL SAFETY SYSTEMS This branch technical position section updates the guidance previously provided in Revision 7, issued August 2016 (Agencywide Documents Access and Management System Accession No. ML16019A344). The main purpose of this update is to clarify sections of the guidance that proved challenging to implement, according to feedback received by internal and external stakeholders. The update improves readability and flow to make it clear to the reader that there is an established process for analyzing potential vulnerabilities to common-cause failures resulting from latent design defects in digital technology, in particular within hardware, and software or software-based logic. The update clarifies the scope of applicability for all users and clearly states that this guidance does not apply to the change process in Title 10 of the Code of Federal Regulations 50.59, “Changes, tests and experiments.” The update provides for structures, systems, and components of differing safety significance, so that an adequate demonstration of safety is consistently applied. It also clarifies specific areas of guidance, such as diversity and testing, and adds the concepts of alternative methods, qualitative assessment, and supporting failure analysis as means of addressing