Document: NUREG-0800
Document ID: 65f2433f-2c4a-4580-b173-0c6da7fa4d73
Document Type: srp
Title: Draft Revision 7 – August 2015
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1515/ML15159A996.pdf
Revision Date: 2023-06
Chapter: 7
Section ID: 7
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555, Attention: Reproduction and Distribution Services Section by fax to (301) 415 2289; or by email to DISTRIBUTION@nrc.gov. Electronic copies of this section are available through the NRC public Web site at http://www.nrc.gov/reading rm/doc collections/nuregs/staff/sr0800, or in the NRC Agencywide Documents Access and Management System (ADAMS), at http://www.nrc.gov/reading rm/adams.html under ADAMS Accession No. ML15159A996. NUREG-0800 U.S. NUCLEAR REGULATORY COMMISSION STANDARD REVIEW PLAN BRANCH TECHNICAL POSITION 7-19 GUIDANCE FOR EVALUATION OF DIVERSITY AND DEFENSE-IN-DEPTH IN DIGITAL COMPUTER-BASED INSTRUMENTATION AND CONTROL SYSTEMS REVIEW RESPONSIBILITIES Primary – Organization responsible for the review of instrumentation and controls (I&C) Secondary – Organization responsible for the review of reactor systems and the organization responsible for the review of human factors engineering (HFE) Review Note: The revision numbers of Regulatory Guides (RG) and the years of endorsed industry standards referenced in this branch technical position (BTP) are centrally maintained in Standard Review Plan (SRP) Section 7.1-T (Table 7-1). Therefore, the individual revision numbers of RGs (except RG 1.97) and years of endorsed industry standards are not shown in this BTP. References to industry standards incorporated by reference into regulation (IEEE Std 279-1971 and IEEE Std 603-1991) and industry standards that are not endorsed by the agency do include the associated year in this BTP. See Table 7-1 to ensure that the appropriate RGs and endorsed industry standards are used for the review. BTP 7-19-2 Draft Revision 7 – August 2015 A. BACKGROUND Digital instrumentation and control (DI&C) systems can be vulnerable to common-cause failure (CCF) caused by software errors or software developed logic, which could defeat the redundancy achieved by hardware architecture. In NUREG-0493, “A Defense-in-Depth and Diversity Assessment of the RESAR-414 Integrated Protection