Document: NUREG-0800
Document ID: 6b7eddf4-f7ce-4821-9f11-e37070221e57
Document Type: srp
Title: DYNAMIC TESTING AND ANALYSIS OF SYSTEMS, STRUCTURES, AND
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1613/ML16133A418.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3.9.2
CFR Part: 
CFR Title: 

Content:
al Static Factors. The use of constant vertical load factors as vertical response loads for the seismic design of all seismic Category I systems, components, equipment, and their supports in lieu of a vertical seismic system dynamic analysis is acceptable only if the structure is rigid in the vertical direction, up to the highest frequency of interest. I. Torsional Effects of Eccentric Masses. For Seismic Category I systems, if the torsional effect of an eccentric mass like a valve operator in a piping system is judged to be significant, the eccentric mass and its eccentricity should be included in the mathematical model. The criteria for significance will have to be determined case by case. J. Seismic Category I Buried Piping Systems. For Seismic Category I buried piping systems, the following items should be considered in the analysis: (i) The inertial effects due to an earthquake upon buried piping systems should be adequately considered in the analysis. Use of the procedures described in the references is acceptable. (ii) The effects of static resistance of the surrounding soil on piping deformations or displacements, differential movements of piping anchors, bent geometry and curvature changes, etc., should be adequately considered. Use of the procedures described in the references is acceptable. (iii) When applicable, the effects of local soil settlements, soil arching, etc., also should be considered in the analysis. K. Interaction of Other Piping with Seismic Category I Piping. To be acceptable, each non-Seismic Category I piping system should be designed to be isolated from any Seismic Category I piping system by either a constraint or barrier or should be located remotely from the Seismic Category I piping system. If isolation of the Seismic Category I piping system is not feasible or practical, adjacent non-Seismic Category I piping should be analyzed according to the same seismic criteria applicable to the Seismic Category I piping system. For