Document: NRC Regulatory Guide
Document ID: 87c94eb7-1d88-4510-b85b-196ad319d0ae
Document Type: regulatory_guide
Title: Software Unit Testing for Digital Computer Software Used in Safety Systems of Nuclear Power Plants + HISTORY - HISTORY 08/2012 – DG-1208 , Proposed Revision 1 08/1996 – DG-1057 , Proposed Revision 0 (Rev. 1)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML1031/ML103120751.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.171
CFR Part: 
CFR Title: 

Content:
ety-related functions of such systems and components. In 10 CFR 50.55a(a)(1) requires, in part, that systems and components be designed, fabricated, erected, tested, and inspected to quality standards commensurate with the safety function to be performed. The regulation in 10 CFR 50.55a(h) requires that reactor protection systems satisfy the criteria in Institute DG-1208, Page 2 of Electrical and Electronics Engineers (IEEE) Standard (Std.) 603-1991, “IEEE Standard Criteria for Safety Systems for Nuclear Power Generating Stations,” including a correction sheet dated January 30, 1995 (Ref. 2), or in IEEE Std. 279-1971, “Criteria for Protection Systems for Nuclear Power Generating Stations” (Ref. 3). These criteria shall be part of the evaluation of the recognized quality codes and standards selected for their applicability, adequacy, and sufficiency and shall be supplemented or modified as needed to assure a quality product and that it will perform the required safety function. The guidance on the safety systems equipment employing digital computers, and programs or firmware requires quality standards be used for testing software units. This regulatory guide endorses American National Standards Institute (ANSI)/IEEE Std. 1008-1987, “IEEE Standard for Software Unit Testing” (Ref. 4), with the exceptions stated in the regulatory positions. ANSI/IEEE Std. 1008-1987, which was reaffirmed in 2002, describes a method acceptable to the NRC staff for complying with NRC regulations for promoting high functional reliability and design quality in the software used in safety systems.1 In particular, the method is consistent with the previously cited GDC in Appendix A to 10 CFR Part 50 and the criteria for quality assurance programs in Appendix B to 10 CFR Part 50 as they apply to software unit testing. The criteria in Appendices A and B apply to systems and related quality assurance processes, and the requirements extend to the software elements if those systems