Document: NUREG-0800
Document ID: 9bcad4cd-a055-4dc1-9315-db9d703e6f6f
Document Type: srp
Title: ENVIRONMENTAL QUALIFICATION OF MECHANICAL AND ELECTRICAL
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1634/ML16343A167.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3.11
CFR Part: 
CFR Title: 

Content:
C 1, “Quality Standards and Records,” GDC 2, “Design Bases for Protection Against Natural Phenomena.” and GDC 23, “Protection System Failure Modes”; and 10 CFR Part 50, Appendix B, Quality Assurance Criteria III, XI, and XVII. In 10 CFR 50.49, “Environmental Qualification of Electric Equipment Important to Safety for Nuclear Power Plants,” the NRC established specific requirements for the environmental qualification of certain electric equipment important to safety located in a “harsh” environment. The regulation defined a “mild” environment as an environment that would at no time be significantly more severe than the environment that would occur during normal plant operation, including anticipated operational occurrences. The NRC stated in 10 CFR 50.49 that environmental qualification of electric equipment located in a “mild” environment was not included within the scope of 10 CFR 50.49. For the purposes of this SRP section, an environment that exceeds NRC’s definition of “mild” will be termed “harsh.” In addition to the overall review of environmental qualification to satisfy 10 CFR Part 50, Appendix A, the review under this SRP section assures conformance to 10 CFR 50.49 for the environmental qualification of electrical equipment important to safety that is located in a harsh environment. 3.11 -3 Draft Revision 4 – December 2017 For mechanical equipment located in a harsh environment, compliance with the environmental design provisions of GDC 4 are generally achieved by demonstrating that the non-metallic parts/components are suitable for the postulated design basis environmental conditions. For electrical, I&C and mechanical equipment located in mild environments, compliance with the environmental design provisions of GDC 4 are generally achieved and demonstrated by proper incorporation of all relevant environmental conditions into the design process, including the equipment specification. In addition, Regulatory Guidance