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:
tial need for the equipment later in an event or during recovery operations, (3) a determination that failure of the equipment after performance of its safety function will not be detrimental to plant safety or mislead the operator, and (4) a determination that the margin applied to the minimum operability time, when combined with the other test margins, will account for the uncertainties associated with the use of analytical techniques in the derivation of environmental parameters, the number of units tested, production tolerances, and test equipment inaccuracies. For all other equipment (e.g., post-accident monitoring), the 10 percent margin for equipment operating time should be used. 5. Remove reference to testing for extreme natural events and severe accidents in Section 6.2, “Type test sample selection,” in IEEE Std. 1682-2023, such that it reads: “Where fiber optic cable and/or connection assemblies are exposed to DBE conditions, they shall be tested, preferably as an assembly.” 6. Remove reference to extreme natural events and severe accidents in Section 6.4, “Age Conditioning,” in IEEE Std. 1682-2023, such that it reads: “Normal operating conditions over time may influence the ability of fiber optic cables and/or connection assemblies to withstand the extreme environments imposed during the DBE.” 7. Regarding vibration (non-seismic) aging, as discussed in Section 6.5.3.2, “Vibration (non- seismic) aging” of IEEE Std. 1682-2023, additional information appears in RG 1.100, RG 1.61, and RG 1.73. Regarding seismic tests in section 6.5.4, “Seismic Tests,” of IEEE Std.1682-2023, additional information appears in RG 1.100. 8. This RG does not endorse Section 6.5.6, “Design extension conditions,” of IEEE Std. 1682-2023. 9. Annex A, “Cable families,” is informative; the endorsement of IEEE Std. 1682-2023 does not include endorsement of Annex A. RG 1.257, Rev. 0, Page 11 D. IMPLEMENTATION Licensees generally are not required to comply