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:
s 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 section to this regulatory guide called “Unambiguity.” This subject in IEEE 830-1998 is important because of the way digital systems interact with a variety of associated software products. As full or partial digital systems are introduced into the nuclear power designs the clarity of the SRS becomes extremely important. This is also the case where associated features during the design phase must be identified, as stated in RG 1.170, “Software Test Documentation for Digital Computer Software Used in Safety Systems of Nuclear Power Plants,” (Ref. 7). The NRC staff recognizes that security features or mechanisms can also play a critical role in supporting software security at higher levels of assurance. IEEE Std. 830-1998 supports this by identifying security as a specific attribute and project objective found in the SRS requirements of the safety software. Subclause 5.3.6.3 of IEEE Std. 830-1998 is not endorsed in this regulatory guide as having sufficient details for protecting software. To meet criteria of IEEE Std. 603-1991 and 10 CFR 50, the development of digital safety system software requires a secure development and operational DG-1209, Page 4 environment (SDOE) be provided, Regulatory Guide 1.152, provides specific guidance concerning the establishment of SDOEs. 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. However, a licensee’s adherence to the provisions of 10 CFR 73.54, “Protection of Digital Computer and Communication Systems and Networks,” (Ref. 8) will be evaluated per regulatory programs specific to that regulation and in accordance with the applicant's