1、ANSI/ANS-2.29-2008probabilistic seismichazards analysisANSI/ANS-2.29-2008ANSI/ANS-2.29-2008American National StandardProbabilistic Seismic Hazards AnalysisSecretariatAmerican Nuclear SocietyPrepared by theAmerican Nuclear SocietyStandards CommitteeWorking Group ANS-2.29Published by theAmerican Nucle
2、ar Society555 North Kensington AvenueLa Grange Park, Illinois 60526 USAApproved July 31, 2008by theAmerican National Standards Institute, Inc.AmericanNationalStandardDesignation of this document as an American National Standard attests thatthe principles of openness and due process have been followe
3、d in the approvalprocedure and that a consensus of those directly and materially affected bythe standard has been achieved.This standard was developed under procedures of the Standards Committee ofthe American Nuclear Society; these procedures are accredited by the Amer-ican National Standards Insti
4、tute, Inc., as meeting the criteria for AmericanNational Standards. The consensus committee that approved the standardwas balanced to ensure that competent, concerned, and varied interests havehad an opportunity to participate.An American National Standard is intended to aid industry, consumers, gov
5、-ernmental agencies, and general interest groups. Its use is entirely voluntary.The existence of an American National Standard, in and of itself, does notpreclude anyone from manufacturing, marketing, purchasing, or using prod-ucts, processes, or procedures not conforming to the standard.By publicat
6、ion of this standard, the American Nuclear Society does not insureanyone utilizing the standard against liability allegedly arising from or afterits use. The content of this standard reflects acceptable practice at the time ofits approval and publication. Changes, if any, occurring through developme
7、ntsin the state of the art, may be considered at the time that the standard issubjected to periodic review. It may be reaffirmed, revised, or withdrawn atany time in accordance with established procedures. Users of this standardare cautioned to determine the validity of copies in their possession an
8、d toestablish that they are of the latest issue.The American Nuclear Society accepts no responsibility for interpretations ofthis standard made by any individual or by any ad hoc group of individuals.Requests for interpretation should be sent to the Standards Department atSociety Headquarters. Actio
9、n will be taken to provide appropriate response inaccordance with established procedures that ensure consensus on theinterpretation.Comments on this standard are encouraged and should be sent to SocietyHeadquarters.Published byAmerican Nuclear Society555 North Kensington AvenueLa Grange Park, Illino
10、is 60526 USACopyright 2008 by American Nuclear Society. All rights reserved.Any part of this standard may be quoted. Credit lines should read “Extracted fromAmerican National Standard ANSI0ANS-2.29-2008 with permission of the publisher,the American Nuclear Society.” Reproduction prohibited under cop
11、yright conventionunless written permission is granted by the American Nuclear Society.Printed in the United States of AmericaForewordThis Foreword is not a part of the American National Standard “ProbabilisticSeismic Hazards Analysis,” ANSI0ANS-2.29-2008.!This standard establishes requirements for p
12、erforming probabilistic seismic haz-ard analyses PSHAs!. It is one of a group of four standards that establishrequirements for the seismic design process for nuclear facilities. FigureA showsthe relationship between this standard and the other three seismic standards:American National Standards Inst
13、itute0American Nuclear Society ANSI0ANS-2.26-2004, “Categorization of Nuclear Facility Structures, Systems, and Compo-nents for Seismic Design”; ANSI0ANS-2.27-2008, “Criteria for Investigations ofNuclear Facility Sites for Seismic HazardAssessments”; andAmerican Society ofCivil Engineers0Structural
14、Engineering Institute ASCE0SEI 43-05, “Seismic De-sign Criteria for Structures, Systems, and Components in Nuclear Facilities.”The procedural relationship among these standards is further described inANSI0ANS-2.26-2004. The user should consult ASCE0SEI 43-05 to see how the infor-mation produced by A
15、NSI0ANS-2.29-2008 is used in developing seismic loadsspecific to a structure, system, or component SSC!.As described in ANSI0ANS-2.26-2004 and ASCE0SEI 43-05, the seismic designprocess for nuclear facilities is based on the consequences of seismically initiatedfailure of SSCs and specified limit sta
16、tes and design requirements. The seismicdesign categories identified in ANSI0ANS-2.26-2004 and the design require-ments in ASCE0SEI 43-05 aim to satisfy target performance goals defined interms of the annual probability of exceeding specified SSC performance. AchievingFigure A Schematic showing the
17、relationships of the seismic standardsia target performance goal is directly related to the probability of a seismic load.Therefore, the results of a PSHA are required as input to the seismic designprocess. ANSI0ANS-2.29-2008 establishes procedures for performing a PSHAneeded to support selection of
18、 the seismic loads used in ASCE0SEI 43-05. Themethods specified herein can also be used to support other applications, such asseismic probabilistic risk analyses.This standard might reference documents and other standards that have beensuperseded or withdrawn at the time the standard is applied. A s
19、tatement hasbeen included in the reference section that provides guidance on the use ofreferences.The ANS-2.29 Working Group of the Standards Committee of the AmericanNuclear Society ANS! had the following membership:J. Savy Chair!, Risk Management Solutions, Inc.J. Ake, U.S. Nuclear Regulatory Comm
20、issionK. Campbell, EQECAT, Inc.N. Chokshi, U.S. Nuclear Regulatory CommissionK. Coppersmith, Coppersmith ConsultingC. Costantino, IndividualC. B. Crouse, URS CorporationA. Hadjian, Defense Nuclear Facilities Safety BoardQ. Hossain, Lawrence Livermore National LaboratoryJ. Kimball, U.S. Department of
21、 EnergyJ. King, IndividualR. Lee, IndividualM. McCann, JBA AssociatesM. Power, Geomatrix Consultants, Inc.G. Toro, Risk Engineering, Inc.I. Wong, URS CorporationR. Youngs, Geomatrix Consultants, Inc.This standard was prepared under the guidance of the Nuclear Facilities Stan-dards CommitteeNFSC! Sub
22、committee ANS-25Siting! of the ANS. At the timeof the ballot, Subcommittee ANS-25 was composed of the following members:Kevin Bryson Chair!, Shaw Environmental, Inc.J. Bollinger, Savannah River National LaboratoryC. Costantino, IndividualP. Fledderman, Westinghouse Savannah River CompanyD. Hang, Uni
23、versity of Illinois-UrbanaK. L. Hanson, Geomatrix Consultants, Inc.J. Litehiser, Bechtel Corporation, Inc.S. Marsh, Southern California Edison CompanyD. Pittman, Tennessee Valley AuthorityJ. Savy, Risk Management Solutions, Inc.R. D. Spence, UT-Battelle, LLCJ. D. Stevenson, J.D. Stevenson nuclear ma
24、terial waste processing,storage, fabrication, and reprocessing facili-ties; uranium enrichment facilities; tritium pro-duction and handling facilities; radioactivematerial laboratories; and nuclear reactors. Cri-teria provided in this standard address variousaspects of conducting PSHAs, including1!
25、selection of the process, the methodologyand the level of seismic hazard analysis ap-propriate for a given seismic design categorySDC!structure, system, or componentSSC!or facility hereafter, the SDC of a facility isconsidered synonymous with the highest SDCSSC in the facility! and the geotechnical
26、andseismological characteristics of the site;2! seismic source characterization;3! ground motion estimation;4! site response assessment;5! assessment of aleatory and epistemic un-certainties in a PSHA;6! PSHA documentation requirements.This standard does not specify methods for es-timating the proba
27、bility of fault displacement,orotherseismicallyinducedhazardssuchassoilliquefaction, soil settlement, landsliding, andearthquake-inducedflooding.Thesehazardsmaybeapplicableforcertainsitesandneedtobeeval-uatedandincludedinSSCdesignrequirements.MethodsfordoingthisareincludedinAmericanSocietyofCivilEng
28、ineers0StructuralEngineer-ing InstituteASCE0SEI 43-05, “Seismic DesignCriteria for Structures, Systems, and Compo-nents in Nuclear Facilities” 2#.This standard does not address criteria, proce-dures, or methods for collecting information anddata required to perform a PSHA. These arespecified in ANSI
29、0ANS-2.27-2008, “Criteria forInvestigations of Nuclear Facility Sites for Seis-mic Hazard Assessments” 3#. In addition, thisstandard does not address the use of PSHAresults or the selection of design-basis earth-quakes for nuclear facilities. This topic is cov-ered in ANSI0ANS-2.26-2004 1# and ASCE0
30、SEI 43-05 2#.The use of this standard shall be coordinatedwith the other three seismic standards namedabove. This coordination is vital to the collec-tion and evaluation of data required to performthe PSHA, to establish the level and scope ofthe analysis consistent with an application, andfor consis
31、tency with the intended use of thePSHA results.The guidelines and requirements provided inthis standard are applicable for the design andevaluation of SDC-3, SDC-4, and SDC-5 facili-ties. These can also be applied to SDC-1 andSDC-2, or other nonU.S. Department of En-ergy DOE! facilities if, for safe
32、ty, economy, orother reasons, a site-specific seismic hazarddetermination becomes necessary.2 Acronyms and terms2.1 AcronymsANS: American Nuclear SocietyANSI: American National Standards Institute1!Numbers in brackets refer to corresponding numbers in Sec. 6, “References.”1ASCE/SEI:American Society
33、of Civil Engineers0Structural Engineering InstituteCEUS: Central and Eastern United StatesCFR: Code of Federal RegulationsDBE: design-basis earthquakeEPRI: Electric Power Research InstituteFS: Fourier amplitude spectrumHLR: high-level requirementsIBC: International Building CodeLHS: Latin hypercube
34、samplingLLNL: Lawrence Livermore National Labora-toryMCE: maximum considered earthquakeM-D: magnitude-distanceNRC: U.S. Nuclear Regulatory CommissionPGA: peak ground accelerationPGD: peak ground displacementPGV: peak ground velocityPSD: power spectral densityPSHA: probabilistic seismic hazard analys
35、isQA: quality assuranceSDC: seismic design categorySSHAC: Senior Seismic Hazard AnalysisCommitteeSSC: structure, system, or componentTFI: technical facilitator integratorTI: technical integratorUHRS: uniform hazard response spectra2.2 Glossary of termsacceptable method: In many places, this stan-dar
36、d contains statements indicating that a cer-tain reference provides an “acceptable method”for satisfying the intent of a given require-ment. The plain meaning of such a statementis that the referenced method is one way tomeet the given requirement. The intent is to bepermissive, meaning that the ana
37、lysis team canuse another method, if justified, without prej-udice. However, it is important to understandthat the intent of the standard goes beyond theplain meaning, as follows: Whenever the phras-ing “acceptable method” is used, the intent isthat if the analysis uses another method, theother meth
38、od must satisfy the stated require-ment with a comparable level of conservatismconsidering a similar level of details pertinentto the analysis scope. It is not acceptable to useanother method that does not satisfy the re-quirement at least as well as the acceptablemethod would satisfy it. Whenever a
39、n alterna-tive to the acceptable method is selected, it isunderstood that the peer review team will payparticular attention to this topic.aleatory variability: The variability inherentin a nondeterministic i.e., stochastic, random!phenomenon. Aleatory variability is accountedfor by modeling the phen
40、omenon in terms of aprobability model. In principle, aleatory uncer-tainty cannot be reduced by the accumulationof more data or additional information, but thedetailed characteristics of the probability modelcan be improved. Sometimes aleatory variabil-ity is called “randomness.”area source: An area
41、 at the surface of theearths crust that is assumed to have experi-enced relatively uniform earthquake sourcecharacteristics for use in the PSHA. See also“volumetric source zone”.!background source zone:Apart of the earthscrust, usually of large surface area dimension,within which potentially damagin
42、g earth-quakes could occur that are not associated ei-ther with known fault sources or even with theuniform pattern, rate, or style of deformationor seismicity commonly identified with volu-metric seismic source zones. In PSHA calcula-tions, earthquakes that cannot be associatedwith other sources de
43、fault to a backgroundsource zone.Central and Eastern United States (CEUS):That portion of the United States east of theRocky Mountains approximately the 104thparallel!.deaggregation: Process used to determine thefractional contribution of each magnitude-distance M-D! pair or of each seismic sourcezo
44、ne, to the total seismic hazard. To accom-plish the M-D deaggregation, a set of bins ofmagnitude and distance pairs is selected, andthe annual probability of exceeding selectedground acceleration parameters from eachAmerican National Standard ANSI0ANS-2.29-20082M-D pair is computed and divided by th
45、e totalprobability of exceedence for all modeledearthquakes.epicenter: The point on the earths surfacedirectly above the focusi.e., hypocenter!of theearthquake source.epistemic uncertainty: Uncertainty attrib-utable to incomplete knowledge about a phe-nomenon that affects the ability to model it.Epi
46、stemic uncertainty is captured by consider-ing a range of model parameters within a givenexpert interpretation or multiple expert inter-pretations and each of which is assigned anassociated weight representing statistical con-fidence in the alternatives. In principle, epi-stemic uncertainty can be r
47、educed by theaccumulation of additional information associ-ated with the phenomenon. The uncertaintyin the parameters of the probability distribu-tion of a random phenomenon is epistemic.ground acceleration: Acceleration at theground surface produced by seismic waves. Typ-ically expressed in units o
48、f gravity g!, the ver-tical acceleration of gravity at the earths surface9.80665 m0s2!.fault:Afracture in the earth along which blocksof crust on either side have moved with respectto one another.fault source: A fault or zone for which thetectonic features causing earthquakes have beenidentified. Th
49、ese are usually individual faults,but they may be zones comprising multiple faultsor regions of faulting if surface evidence of thesefaults is lacking but the faults are suspectedfrom seismicity patterns, tectonic interpreta-tions of crustal stress and strain, and otherevidence. Regions of blind thrust faults are agood example of the latter.hazard curve: A curve that gives the proba-bility of a certain ground motion parameterusually the PGA, PGV, or response spectralvalues!being exceeded. Hazard curves are gen-erally generated for periods of exposure of
