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:
to safety and located in a harsh environment. However, certain NUREG-0588 Category I guidance may be used if relevant guidance is not provided in RG 1.89. NUREG-0588 includes two sets of qualification criteria, Category I and Category II. Category I refers to Institute of Electrical And Electronics Engineers (IEEE) Standard (Std.) 323-1974, “IEEE Standard 3.11 -11 Draft Revision 4 – December 2017 for Qualifying Class 1E Equipment for Nuclear Power Generating Stations.” Category II refers to IEEE Std. 323-1971, and is not applicable to any future plants. 2. IEEE Std. 323 contains the principles and criteria that are generic to the environmental qualification process. The following clarification related to the criteria in IEEE Std. 323 should be considered. IEEE Std. 323 requires that the service environment, including the installed configuration of the equipment, be considered as part of the qualification process. In meeting this requirement, the potential for flooding of electrical equipment that are installed above the flood level, but are subject to water and moisture intrusion, should be considered as part of environmental qualification. Operating experience (e.g., Information Notice 89-63) shows that electrical enclosures that are located above the flood level and are subject to water and moisture intrusion could result in submergence of electrical components inside the enclosures, if the enclosures do not have drainage holes. The reviewer should confirm that equipment in such locations, whose design is such that water accumulation is possible, should have measures to preclude such accumulation (e.g., enclosure drain holes) or the affected equipment should be qualified for the anticipated submergence. 3. RG 1.40, “Qualification Tests of Continuous-Duty Motors Installed Inside the Containment of Water-Cooled Nuclear Power Plants,” endorses IEEE Std 334, “IEEE Trial Use Guide for Type Tests of Continuous-Duty Class 1 Motors Installed Inside the