Document: NRC Regulatory Guide
Document ID: b3436475-0452-4460-897e-ef2d0023a709
Document Type: regulatory_guide
Title: Guidelines for Lightning Protection of Nuclear Power Plants (Rev. 1)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML2220/ML22208A232.pdf
Revision Date: 2023-05
Chapter: 
Section ID: RG-1.204
CFR Part: 
CFR Title: 

Content:
res at power generating stations. As such, this standard identifies the grounding practices that the electric utility industry has generally accepted as contributing to effective grounding systems for personnel safety and equipment protection in generating stations. This standard also provides guidance for the design of generating station grounding systems and grounding practices applied to generating station indoor and outdoor structures and equipment. IEEE Std. 666-2007 describes grounding practices for neutral grounding and grounding methods for medium-voltage equipment. As such, this standard is a design guide intended for application to generating station service systems that supply electric power to auxiliary equipment. This design guide applies to all types of generating stations that produce electric power and is particularly applicable to stations in which the electric power service is required to perform continuously. Such a service system consists of a main auxiliary power distribution network that might supply many subsystems (including direct current systems and Class 1E power systems), much of which is medium-voltage (2.4-13.8 kV) equipment. This standard addresses recommendations for neutral grounding, as well as the grounding of generating station auxiliaries. It also covers grounding methods for both low-voltage (120-480 V) and medium-voltage power service systems. The low-voltage grounding methods parallel similar guidance in IEEE Std. 665. In addition, this standard covers surge protection of transformers, switchgear, and motors, paralleling similar guidance in IEEE Std. C62.23. IEEE Std. 1050-2004 describes design and installation practices regarding grounding methods for I&C equipment. As such, this standard recommends grounding methods for I&C equipment to achieve a DG-1409, Page 5 suitable level of protection for personnel and equipment, as well as suitable noise immunity for signal- ground references in generating stations. IEEE Std.