Document: NUREG-0800
Document ID: b91646e8-0b07-4d85-a5e4-783b27cdcd88
Document Type: srp
Title: SEISMIC AND DYNAMIC QUALIFICATION OF MECHANICAL AND
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0520/ML052070286.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3.10
CFR Part: 
CFR Title: 

Content:
o supplement the staff's review procedures. 3. Reviews of COL applications should include audits of the equipment qualification file. Results of tests and analyses should be reviewed to accomplish the following: a. Ensure that the criteria in the certified design were properly implemented, b. Ensure that adequate qualification was demonstrated for all equipment and their supports, and c. Verify that all applicable loads were properly defined and accounted for in the testing and analyses that were performed.79 In the ABWR and System 80+ design certification FSERs the staff accepted an exemption from the 10 CFR 100 Appendix A requirement that all safety-related structures, systems, and components be designed to remain functional and within applicable stress and deformation limits when subjected to an OBE. This exemption was based on the licensees' alternative analyses performed for the SSE and procedural requirements to perform an inspection of the plant following an earthquake at or above one-third the SSE. The staff concluded in SECY 93-087 (Reference 25) that the effect of eliminating the OBE from equipment qualification by analysis should be negligible. Mechanical equipment is generally seismically rugged when properly anchored and its tolerance limits are controlled by the SSE rather than the OBE. However, some electrical equipment qualified by seismic analysis requires an assumed number of OBE events followed by one SSE event. With the elimination of OBE, analysis checks for fatigue effects can be performed at a fraction of the SSE. The staff concluded that equipment should be qualified with five one-half SSE events followed by one full SSE event. Or alternatively, a number of fractional peak cycles equivalent to the maximum peak cycle for five one-half SSE events may be used in accordance with Appendix D of IEEE Standard 344-1987 when followed by one full SSE.80 For standard design certification reviews under 10 CFR Part 52, the procedures above should be