Document: NRC Regulatory Guide
Document ID: e16da529-b6b4-4fdf-bc3f-7490180363f3
Document Type: regulatory_guide
Title: Environmental Qualification of Certain Electric Equipment Important to Safety for Nuclear Power Plants (Rev. 2)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML2018/ML20183A423.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.89
CFR Part: 
CFR Title: 

Content:
d describes principles, methods, and procedures for qualifying, maintaining, and extending qualification, as well as updating qualification, of safety-related electrical equipment that is important to safety and interfaces that are to be used in nuclear power plants, including components or equipment of any interface whose failure could adversely affect any safety- related equipment. The staff is revising RG 1.89 to endorse IEC/IEEE 60780-323, Edition 1, 2016-02, with clarifications, as this standard reflects almost 40 years of experience gained in implementing regulatory requirements and industry research and testing related to EQ. Nuclear plant license renewal provides additional motivation for continuing attention to equipment qualification. This revised guide contains information specific for EQ for both older plants and newer reactors licensed under both 10 CFR Parts 50 and 52. Background It is essential that safety-related electric equipment that is important to safety be qualified to demonstrate that it can perform its safety function under the environmental service conditions in which it will be required to function and for the length of time its function is required. Nonsafety-related electric equipment covered by 10 CFR 50.49(b)(2) must also be able to withstand environmental stresses caused by design-basis events under which its failure could prevent the satisfactory accomplishment of safety functions. This concept applies throughout this guide. The specific environment for which individual electric equipment must be qualified will depend on the installed location and the conditions under which it is required to perform its safety function. The requirements on electrical equipment located in a harsh environment are more stringent, since these components are generally not serviceable (i.e., not able to be accessed to replace or maintain) after the onset of a design basis event. For the purposes of this guide, the primary objective of “qualification” is