Document: NUREG-0800
Document ID: 29f5ac9f-4962-4021-913a-6375076e03fd
Document Type: srp
Title: SEISMIC SYSTEM ANALYSIS
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0523/ML052340566.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3.7.2
CFR Part: 
CFR Title: 

Content:
difficult higher-frequency modes need not be determined. The procedure ensures inclusion of all modes of the structural model and proper representation of DOF masses. An acceptable alternative to this procedure is as follows: Modal responses are computed for enough modes to ensure that the inclusion of additional modes does not increase the total response by more than 10 percent. Modes that have natural frequencies less than that at which the spectral acceleration approximately returns to the ZPA (33 Hz in the case of Regulatory 3.7.2-24 Rev. 0 - August 1989 , . A '.. 2 Guide 1.60 response spectra) are combined in accordance with Reference 8. Higher-mode responses are combined algebraically (i.e., retain sign) with each other. The absolute value of the combined higher modes is then added directly to the total response from the combined lower modes. 3.7.2-25 Rev. 2 - Auggst 1909 .1 NRC FORV 335 U.S. NUCLEAR REGULATORY COMMISSION 1. REPORi %.MBERt 0491 Amas~of by NRC. Add VVo.. Sum.o. Rev.. NRCM110. ad Addssdum Numbmr. If ony.1 32013"2 BIBLIOGRAPHIC DATA SHEET NUREG-0800 tser nstnucions on the reverse Section 3.7.2 2. TITLE AND SUBTITLE Revision 2 Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power Plants, LWR Edition 3. DATE REPORT PL'BLISHEn MOstI t1 I stHn Revision 2 to SRP Section 3.7.2, "Seismic System Analysis" Novemtber 1989 4. FIN OR GRANT NUMBER 5. AUTHORIS) 6. TYPE OF REPORT 7.PERIOD COVERED rglw ace . I4-UMN gtLIIene Isss lfre- IAMle *-nL rustfle~ FWfLn. racesa ::_WA As: ,D,_m U___ VUAd ffWU' LVjMW~.. _ o._.w.._l_, a. VERIOH!IUINGi OR1UArIzA ITIV -NP M AMA AJUUIJV:zQ ir vl K9° rtnWnso.o Aoran V50 NU-lnr a-1J7V cnin ot nvb- du 1)Ottrtt n Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, D.C. 20555 9. SPONSORING ORGANIZATION -NAME AND ADDR ESS ftli orc. tre$~weso ^ -^ /trtrac, DvN~ofkor Rn. 00kr tn Fin, U.S huko .°Atrrofy Crtmi... -m a- adbovi Same as above. 10. SUPPLEMENTARY NOTES 1. ABSTRACT