Document: NUREG-0800
Document ID: 611e1a8a-5fb2-4d1d-8b0e-7561bc7e46ac
Document Type: srp
Title: SEISMIC AND DYNAMIC QUALIFICATION OF MECHANICAL AND ELECTRICAL EQUIPMENT
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0523/ML052340654.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3.10
CFR Part: 
CFR Title: 

Content:
4-1971 should be reevaluated to justify the appropriateness of the input motion used, and requalified if necessary. (6) For the seismic and dynamic portion of the loads the test input motion should be applied to one vertical axis and one principal horizontal axis (or two orthogonal horizontal axes) simultaneously unless it can be demonstrated that the equipment response in the vertical direction is not sensitive to the vibratory motion in the horizontal direction, and vice versa. The time phasing of the inputs in the vertical and horizontal directions must be such that a purely rectilinear resultant input is avoided. An acceptable alternative is to test with vertical and horizontal inputs in-phase, and then repeat the test with inputs 180 degrees out-of-phase. In addition, the test must be repeated with the equipment rotated 90 degrees horizontally. Components that have been previously tested to IEEE Std. 344-1971 should be requalified using biaxial test input motions unless 3.10-4 Rev. 2 - July 1981 justification for using a single axis test input motion is provided. (7) Dynamic coupling between the equipment and related systems, if any, such as connected piping and other mechanical components, should be considered. (8) The fixture design should simulate the actual service mounting and should not cause any extraneous dynamic coupling to the test item. (9) For pumps and valves, the loads imposed by the attached piping should be properly taken into account. In order to assure operability under combined loadings, the stresses resulting from the applied test loads should envelope the specified service stress limit for which the component's operability is intended.c (10) If the dynamic testing of a pump or valve assembly proves to be impracticable, static testing of the assembly is acceptable provided that the end loadings are conservatively applied and are equal to or greater than postulated event loads, all dynamic amplification effects are accounted for, the