Document: NUREG-0800
Document ID: dc63e8aa-2a74-4078-9e19-9a26ed1b4d8c
Document Type: srp
Title: Revision 6 – July 2012
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1105/ML110550791.pdf
Revision Date: 2023-06
Chapter: 7
Section ID: 7
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CFR Title: 

Content:
. 7-4.3.2 is provided in Standard Review Plan (SRP), Chapter 7, Appendix 7.1-D. RG 1.62, Revision 1, “Manual Initiation of Protective Actions,” includes information on diverse manual initiation of protective action. NUREG/CR-6303, “Method for Performing Diversity and Defense-in-Depth Analyses of Reactor Protection Systems,” summarizes several D3 analyses performed after 1990 and presents a method for performing such analyses. The SRM on SECY-93-087 describes the NRC position on D3 in Item 18, II.Q. Generic Letter (GL) 85-06, “Quality Assurance Guidance for ATWS Equipment that is not Safety-Related,” April 16, 1985, provides quality assurance guidance for non-safety-related ATWS equipment. NUREG-0800, SRP Chapter 18, Appendix 18-A, "Crediting Manual Operator Actions in Diversity and Defense-in-Depth (D3) Analyses," defines a methodology, applicable to both existing and new reactors, for evaluating manual operator actions as a diverse means of coping with AOOs and postulated accidents that are concurrent with a software CCF of the DI&C protection system. NUREG-0800, SRP Section 7.8, “Diverse Instrumentation and Control Systems,” describes the review process and additional acceptance criteria for diverse I&C systems provided to protect against CCF. Revision 6 – July 2012 BTP 7-19-5 3. Purpose The purpose of this BTP is to provide guidance for evaluating an applicant’s D3 assessment, design, and the design of manual controls and displays to ensure conformance with the NRC position on D3 for I&C systems incorporating digital, software-based or software-logic-based RTS or ESF, auxiliary supporting features, and other auxiliary features as appropriate. This BTP has the objective of confirming that vulnerabilities to CCF have been addressed in accordance with the guidance of the SRM on SECY-93-087 and clarification provided in this staff guidance, specifically: ● Verify that adequate diversity has been provided in a design to meet the criteria