Document: NRC Regulatory Guide
Document ID: d6326081-f430-476d-8098-4edf00868dd9
Document Type: regulatory_guide
Title: Verification, Validation, Reviews, and Audits for Digital Computer Software Used in Safety Systems of Nuclear Power Plants + HISTORY - HISTORY 08/2012 – DG-1267 , Proposed Revision 2 01/2003 – DG-1123 , Proposed Revision 1 08/1996 – DG-1054 , Proposed Revision 0 (Rev. 2)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML1031/ML103160431.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.168
CFR Part: 
CFR Title: 

Content:
ry Guide 1.168, Staff Regulatory Guidance item 2 has expanded on the topic of independence and provides clarification for organizational mapping as per IEEE Std. 1012-2004, Annex F. The new concept of conditional independence in Annex C, Table C.1 is not acceptable to the NRC. As for the new activity in IEEE Std. 1012-2004 called “Security Analysis,” the NRC finds this consistent with a life-cycle approach and has altered the Regulatory Guide 1.168 position in Part C, 7.c, to what is now called a ”Secure Analysis.” This regulatory guide has expanded from the original Regulatory Guide 1.168-2004 version which states that only vital equipment must be protected by physical barriers and access control. IEEE Std. 1012-2004 established a new task for many of the V&V activities called "Security Analysis" (see Table 1 for a comprehensive overview of the application of this new task). This new security analysis task is intended to address accidental and malicious activities that can affect the software. The NRC does not support this activity as a means to address malicious acts that may damage the software. Furthermore, the NRC has established a V&V life-cycle approach for the accidental or non- malicious acts by providing a secure development and operational environment (SDOE) guidance when developing a digital safety system. To meet criteria of IEEE Std. 603-1991 and 10 CFR 50, the development of digital safety system software requires a SDOE be provided, Regulatory Guide 1.152, provides specific guidance concerning the establishment of SDOEs. The NRC staff recognizes that SDOE features or mechanisms can also play a critical role in supporting software security at higher levels of assurance. Applicants should be aware that other NRC requirements and guidance may lead to specific cyber security controls during the software development process and/or the inclusion of security features in or around digital safety systems. Specifically a licensee’s adherence to the