Document: NRC Regulatory Guide
Document ID: 2980f2d9-2e7d-4afa-9e1f-a8abe5fb7507
Document Type: regulatory_guide
Title: Software Requirement Specifications for Digital Computer Software and Complex Electronics Used in Safety Systems of Nuclear Power Plants + HISTORY - HISTORY 08/2012 – DG-1209 , Proposed Revision 1 08/1996 – DG-1058 , Proposed Revision 0 (Rev. 1)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML1030/ML103080963.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.172
CFR Part: 
CFR Title: 

Content:
criteria of Appendix A, this regulatory guide refers to software incorporated into the instrumentation and control systems covered by Appendix B to 10 CFR Part 50 as “safety system software.” The SRS is an essential part of the record of the design of safety system software. Software requirements are associated with the system requirements allocated to software subsystems and serve as the design bases for the software under development. Therefore, SRSs are a crucial design input to the remainder of the software development process. SRSs should exhibit characteristics such as correctness and completeness that will facilitate the implementation of a carefully planned and controlled software development process. Appendix B to 10 CFR Part 50 provides quality assurance criteria that the design documentation for nuclear reactor safety systems must meet through design control measures. Criterion III, “Design Control,” of Appendix B requires licensees to develop these control measures for design documentation and identification and the control of design interfaces and measures for verifying or checking the adequacy of the design. Description of Change The original version of this regulatory guide endorsed IEEE Std. 830-1993. There are only minor changes between IEEE Std. 830-1998 and the original 1993 version. This version of Regulatory Guide 1.172 endorses IEEE Std. 830-1998, specifically addresses Annex B, and corrects three other perspectives associated with the software attributes of an SRS. The addressed areas are: the enhancements in “Security,” “Unambiguity” and the deleting an existing regulatory guide section called “Nonapplicability.” The original regulatory guide contained a section called “Nonapplicability,” which has been removed from this version, because of the changes in the way software is viewed and documented. All subjects associated with the development of safety system are applicable for review. Within this same venue is a new