Document: NRC Regulatory Guide
Document ID: b4874b3a-bbf8-4eb6-8b86-db32ecf45ac6
Document Type: regulatory_guide
Title: Guidance for Implementation of 10 CFR 50.59, Changes, Tests, and Experiments (Rev. 2)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML1904/ML19045A435.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.187
CFR Part: 
CFR Title: 

Content:
.59(b) to correct minor errors in the regulatory text. The 2007 rulemaking amended 10 CFR Part 52 and made associated conforming changes to 10 CFR 50.59(b), 50.59(d)(2) and (3). The rulemakings caused portions of NEI 96-07, Revision 1 to be obsolete. In particular, the text of 10 CFR 50.59 in Appendix A to NEI 96-07, Revision 1, “Text of 10 CFR 50.59” was no longer current, and NEI 96-07, Revision 1, pre-dated the current version of 10 CFR Part 52. In May 2019, the NRC issued RG 1.187, Revision 1 (Ref. 17), that clarified certain statements in NEI 96-07, Revision 1, Section 4.3.5 regarding the meaning of “accidents of a different type,” and Section 4.3.8 regarding the definition of “…departure from a method of evaluation…”. Digital Modifications Background Modifications of I&C systems can involve installation of new systems or components that use digital technology, replacement of analog devices with digital technology, or updating existing digital equipment. By letter dated March 15, 2002, NEI submitted the Electric Power Research Institute (EPRI) report, “Guideline on Licensing Digital Upgrades EPRI TR-102348 Revision 1,” (NEI 01-01) (Ref. 18), for the NRC staff’s review. NEI 01-01 replaced the original version of EPRI TR-102348, issued December 1993 (Ref. 19), which the NRC endorsed in Generic Letter 1995-02, “Use of NUMARC/EPRI Report TR-102348, ‘Guideline of Licensing Digital Upgrades,’ in Determining the Acceptability of DG-1356, Page 5 Performing Analog-to-Digital Replacements under 10 CFR 50.59 (Ref. 20). On November 25, 2002, the NRC issued NRC Regulatory Issue Summary (RIS) 2002-22, “Use of EPRI/NEI Joint Task Force Report, ‘Guideline on Licensing Digital Upgrades: EPRI TR-102348, Revision 1, NEI 01-01: a revision of EPRI TR 102348 to Reflect Changes to the 10 CFR 50.59 Rule’” (Ref. 21). RIS 2002-22 endorsed NEI 01-01 as guidance in designing and implementing digital upgrades to nuclear power plant I&C systems. Following