Document: NRC Regulatory Guide
Document ID: c6321e39-3d1b-40a6-ace3-8c6a0c54e2cd
Document Type: regulatory_guide
Title: Developing Software Life Cycle Processes for Digital Computer Software Used in Safety Systems of Nuclear Power Plants + HISTORY - HISTORY 08/2012 – DG-1210 , Proposed Revision 1 08/1996 – DG-1059 , Proposed Revision 0 (Rev. 1)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML1031/ML103120727.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.173
CFR Part: 
CFR Title: 

Content:
to be performed for each phase to address hazards and abnormal conditions and events. c. Output Information. The software safety analysis reports the information for the current phase activities. The licensee or applicant should use this information for the design DG-1210, Page 9 activities of the current life-cycle phase, subsequent software safety analysis activities, the software configuration management process, and the verification and validation processes. 4. New or Modified Safety System Software Criterion XV of Appendix B to 10 CFR Part 50 requires measures to be established to control materials, parts, or components that do not conform to requirements in an effort to prevent their inadvertent use or installation. The following clarifications should be made to IEEE Std. 1074-2006 with respect to the installation and operation of new or modified safety system software: a. Temporary Work-Around. In its overview discussion of the installation process, Section A.4.1 of Annex A to IEEE Std. 1074-2006 states, “If a problem arises, it shall be identified and reported. If necessary, and possible, a temporary work-around may be applied.” For the purposes of this regulatory guide, the term “work-around” is defined as a temporary change to either the software or its configuration that is made for the purpose of allowing the continuation of the installation activities and testing of parts of the software that are unaffected by the temporary change. A temporary work-around is not permitted in any safety system unless all software changes are performed in accordance with the software configuration controls and the changed software is checked in an off- line mode prior to installation. b. Installation. Installation of new or modified safety system software may be performed only when all functions affected by the software have been declared inoperable in accordance with the plant technical specifications. When software is involved, particularly for distributed