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:
portant to safety can perform its safety function(s) without experiencing common-cause failures during and after applicable DBEs. The NRC defines DBEs in 10 CFR 50.49(b)(1)(ii) as conditions of normal operation, including anticipated operational occurrences, design-basis accidents, external events, and natural phenomena for which the plant must be designed to ensure the functions listed in 10 CFR 50.49(b)(1)(i)(A) through (C). For the mitigation of beyond-DBEs, requirements such as 10 CFR 50.155(c) mandate that equipment relied on for mitigation must have sufficient capacity and capability to perform the necessary functions. Type testing, as discussed in IEEE Std. 1682-2023 Section 5.2, could be used to demonstrate the capability of equipment to perform credited functions under extreme natural events or severe accident/design extension conditions. In relation to the installation of fiber-optic cables, IEEE Std. 1428-2004, “IEEE Guide for Installation Methods for Fiber Optic Cables in Electric Power Generating Stations and in Industrial Facilities” (Ref. 25), provides guidance on selecting, applying, and installing fiber-optic cable. The NRC staff reviewed IEEE Std. 1428-2004 and found that this document contains information on installation methods for fiber-optic cables. However, this RG does not endorse IEEE Std. 1428-2004. Consideration of International Standards The International Atomic Energy Agency (IAEA) works with member states and other partners to promote the safe, secure, and peaceful use of nuclear technologies. The IAEA develops Safety Requirements and Safety Guides for protecting people and the environment from harmful effects of ionizing radiation. This system of safety fundamentals, safety requirements, safety guides, and other relevant reports reflects an international perspective on what constitutes a high level of safety. To inform its development of this RG, the NRC considered IAEA Safety Requirements and Safety Guides pursuant to the