Document: NRC Regulatory Guide
Document ID: 50995365-d97f-4101-970a-378af6b5374b
Document Type: regulatory_guide
Title: Qualification of Fiber-Optic Cables, Connections, and Optical Fiber Splices for Use in Safety Systems for Production and Utilization Facilities (Rev. 0)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML2505/ML25052A253.pdf
Revision Date: 2025-08
Chapter: 
Section ID: RG-1.257
CFR Part: 
CFR Title: 

Content:
U.S. NUCLEAR REGULATORY COMMISSION REGULATORY GUIDE 1.257, REVISION 0 Issue Date: August 2025 Technical Lead: Sheila Ray Written suggestions regarding this guide may be submitted through the NRC’s public website in the NRC Library at https://www.nrc.gov/reading-rm/doc-collections/reg-guides/index.html, under Document Collections, in Regulatory Guides, at https://www.nrc.gov/reading-rm/doc-collections/reg-guides/contactus.html, and will be considered in future updates and enhancements to the “Regulatory Guide” series. During the development process of new guides suggestions should be submitted within the comment period for immediate consideration. Suggestions received outside of the comment period will be considered if practical to do so or may be considered for future updates. Electronic copies of this RG, previous versions of RGs, and other recently issued guides are also available through the NRC’s public website in the NRC Library at https://www.nrc.gov/reading-rm/doc-collections/reg-guides/index.html under Document Collections, in Regulatory Guides. This RG is also available through the NRC’s Agencywide Documents Access and Management System (ADAMS) at https://www.nrc.gov/reading-rm/adams.html, under ADAMS Accession Number (No.) ML25052A253. The regulatory analysis is associated with non-rulemaking and may be found in ADAMS under Accession No. ML24201A069. The associated draft guide, DG-1427, may be found in ADAMS under Accession No. ML24201A068, and the staff responses to the public comments on DG-1427 may be found under ADAMS Accession No. ML25052A132. QUALIFICATION OF FIBER-OPTIC CABLES, CONNECTIONS, AND OPTICAL FIBER SPLICES FOR USE IN SAFETY SYSTEMS FOR PRODUCTION AND UTILIZATION FACILITIES A. INTRODUCTION Purpose This regulatory guide (RG) describes an approach that is acceptable to the staff of the U.S. Nuclear Regulatory Commission (NRC) for use in complying with NRC regulations that address the environmental qualification (EQ) of fiber-optic