1、ANSI/ANS-2.27-2008criteria for investigations ofnuclear facility sites forseismic hazard assessmentsANSI/ANS-2.27-2008ANSI/ANS-2.27-2008American National StandardCriteria for Investigations ofNuclear Facility Sites forSeismic Hazard AssessmentsSecretariatAmerican Nuclear SocietyPrepared by theAmeric
2、an Nuclear SocietyStandards CommitteeWorking Group ANS-2.27Published by theAmerican Nuclear Society555 North Kensington AvenueLa Grange Park, Illinois 60526 USAApproved July 31, 2008by theAmerican National Standards Institute, Inc.AmericanNationalStandardDesignation of this document as an American N
3、ational Standard attests thatthe principles of openness and due process have been followed 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 N
4、uclear Society; these procedures are accredited by the Amer-ican National Standards Institute, 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
5、 to participate.An American National Standard is intended to aid industry, consumers, gov-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
6、, or using prod-ucts, processes, or procedures not conforming to the standard.By publication 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
7、 at the time ofits approval and publication. Changes, if any, occurring through developmentsin 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 It may be reaffirmed, revised, or withdrawn atany time in accordance with established procedures.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
8、 of this standardare cautioned to determine the validity of copies in their possession and 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 fo
9、r interpretation should be sent to the Standards Department atSociety Headquarters. Action 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 SocietyHeadquart
10、ers.Published byAmerican Nuclear Society555 North Kensington AvenueLa Grange Park, Illinois 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-2.27-2008 with per
11、mission of the publisher,the American Nuclear Society.” Reproduction prohibited under copyright conventionunless written permission is granted by the American Nuclear Society.Printed in the United States of AmericaForewordThis Foreword is not part of American National Standard “Criteria for Investig
12、ations ofNuclear Facility Sites for Seismic Hazard Assessments,” ANSI0ANS-2.27-2008.!This standard provides requirements and recommended practices for conductinginvestigations and acquiring data sets needed to characterize seismic sources forprobabilistic seismic hazard analysis PSHA!. The data sets
13、 provide informationfor site response and soil-structure interaction analyses needed for design ofthose facilities. They also are used to evaluate fault rupture and associatedsecondary deformation and other seismically induced ground failure hazardse.g., liquefaction, ground settlement, slope failur
14、e!.This standard is one of a group of four standards that establish requirements forthe seismic design of nuclear facilities. The overall objective of these standards isto achieve a risk-informed design that protects the public, the environment, andworkers from potential consequences of earthquakes.
15、 The other three standardsare American National Standards Institute0American Nuclear Society ANSI0ANS-2.26-2004, “Categorization of Nuclear Facility Structures, Systems, andComponents for Seismic Design”; ANSI0ANS-2.29-2008, “Probabilistic SeismicHazards Analysis”; and American Society of Civil Engi
16、neers0Structural Engi-neering Institute ASCE0SEI 43-05, “Seismic Design Criteria for Structures, Sys-tems, and Components in Nuclear Facilities.” The procedural relationship amongthese four standards is shown in Fig. A.The seismic design process for nuclear facilities is based on the consequences of
17、seismic-initiated failure of structures, systems, and components SSCs!. TheFigure A Schematic showing the relationships of the seismic standardsiseismic design categories identified in ANSI0ANS-2.26-2004 and the design re-quirements specified in ASCE0SEI 43-05 satisfy target performance goals de-fin
18、ed in terms of the annual probability of exceeding specified SSC performancelimits. Achieving a target performance goal is directly related to the probabilityof occurrence of a seismic load that is beyond design specifications. ANSI0ANS-2.29-2008 establishes procedures for performing a PSHA needed t
19、o supportselection of the seismic loads used in ASCE0SEI 43-05. This standard providesguidance for the geological and geotechnical investigations needed to provideinformation to support a! seismic source characterization input to the PSHA,b! evaluation of surface fault rupture hazards, c! site respo
20、nse analyses, andd! seismic-induced ground failure hazards.This standard might reference documents and other standards that have beensuperseded or withdrawn at the time the standard is applied. A statement hasbeen included in the reference section that provides guidance on the use ofreferences.Worki
21、ng Group ANS-2.27 of the ANS-25 Subcommittee to the Nuclear FacilitiesStandards Committee NFSC! of the American Nuclear Society ANS! had thefollowing membership at the time of approval of this standard:K. L. Hanson Chair!, Geomatrix Consultants, Inc.W. R. Lettis Vice Chair!, William Lettis 2! evalua
22、tion of surface fault rupture hazard;3! site response analysis;4! seismic-induced ground failure hazard.These criteria are applicable for Seismic De-sign CategorySDC!-3, SDC-4, and SDC-5 struc-tures, systems, or components SSCs!.This standard does not address the use ofPSHA results or the selection
23、of design-basisevents for nuclear facilities. These topics arecovered in American National StandardsInstitute0American Nuclear Society ANSI0ANS-2.26-2004, “Categorization of Nuclear FacilityStructures, Systems, and Components for Seis-mic Design” 1#1!and American Society of CivilEngineers0Structural
24、 Engineering InstituteASCE0SEI 43-05, “Seismic Design Criteria forStructures, Systems, and Components in Nu-clear Facilities” 2#.This standard is one of a series of nationalstandards designed to provide criteria andguidelines to promote uniform and effectiveassessment of seismic hazards at nuclear f
25、a-cilities. These hazards must be properly iden-tified and characterized commensurate withthe level of risk and design requirements as-sociated with each nuclear facility as speci-fied in ANSI0ANS-2.26-2004 1# and ASCE0SEI 43-05 2#. As defined in ANSI0ANS-2.26-2004 1#, a nuclear facility is a facili
26、ty thatstores, processes, tests, or fabricates radio-active materials in such form and quantitythat a nuclear risk to the workers, to theoff-site public, or to the environment may ex-ist. These include, but are not limited to, nu-clear fuel manufacturing facilities; nuclearmaterial waste processing,
27、 storage, fabrica-tion, and reprocessing facilities; uranium en-richment facilities; tritium production andhandling facilities; and radioactive materialslaboratories. Additional criteria may be spec-ified by the applicable regulatory authority.This standard outlines standard criteria andprocedures t
28、o collect data needed as input toprobabilistic analysis of seismic hazards atnuclear facilities as specified in ANSI0ANS-2.29-2008, “Probabilistic Seismic HazardsAnalysis”3#.Appropriate approaches are out-lined to ensure that the current state-of-the-art methodology is being used in the sitecharacte
29、rization. The selection of specific tech-niques and level of detail required to assessseismic and seismic-induced hazards is de-pendent on both the nature of the nuclearfacility i.e., SDC2!as defined by ANSI0ANS-2.26-2004 1#!and site-specific conditions.3!2 Acronyms and definitions2.1 List of acrony
30、msANS: American Nuclear SocietyANSI: American National Standards InstituteASCE/SEI:American Society of Civil Engineers0Structural Engineering InstituteASTM: American Society for Testing andMaterialsBPT: Becker penetration test1!Numbers in brackets refer to corresponding numbers in Sec. 5, “Reference
31、s.”2!The SDCs used in this standard are not the same as the SDCs referred to in the International Building CodeIBC!.3!In this standard, material that is double-indented indicates a commentary.1CEUS: Central and Eastern United StatesCPT: cone penetration testEPRI: Electric Power Research InstituteGPS
32、: global positioning systemIBC: International Building CodeLiDAR: light detection and radarMCE: maximum considered earthquakeNEHRP: National Earthquake Hazards Reduc-tion ProgramNRC: U.S. Nuclear Regulatory CommissionPGA: peak ground accelerationPGV: peak ground velocityPSHA: probabilistic seismic h
33、azard analysisQA: quality assuranceRQD: rock quality designationSASW: spectral analysis of surface wavesSDC: seismic design categorySPT: standard penetration testSSC: structure, system, or componentSSHAC: Senior Seismic Hazard AnalysisCommitteeSSI: soil-structure interactionUHRS: uniform hazard resp
34、onse spectra2.2 Definitionsaccelerogram: A representation either re-corded, modified recorded, or synthetic! of theacceleration of the ground during an earth-quake. The accelerogram contains acceleration-time-data pairs.aleatory variability: The variability inher-ent in a nondeterministic i.e., stoc
35、hastic, ran-dom! phenomenon see “variability”!. Aleatoryvariability is accounted for by modeling thephenomenon in terms of a probability model.In principle, aleatory uncertainty cannot bereduced by the accumulation of more data oradditional information, but the detailed char-acteristics of the proba
36、bility model can be im-proved. Sometimes aleatory variability is called“randomness.”area source: An area of the earths crust thatis assumed to have relatively uniform earth-quake source characteristics for use in thePSHA. See also “volumetric source zone.”!background source zone:Apart of the earthsc
37、rust, usually of large areal dimension, withinwhich potentially damaging earthquakes couldoccur that are not associated either with knownfault sources or even with the uniform pattern,rate, or style of deformation or seismicity com-monly identified with volumetric seismic sourcezones. In PSHA calcul
38、ations, earthquakes thatcannot be associated with other sources defaultto a background source zone.blind fault: A blind fault is a fault that doesnot rupture all the way up to the surface andconsequently does not have a surface trace.These features are usually associated withthrust faults, which are
39、 formed by compressivestresses. Blind thrust faults do not penetratethe uppermost layers of crust, but they causethe surface layers to fold over them as theydeform, forming a telltale hill at the surfacethat reveals their presence to observers.Central and Eastern United States (CEUS):That portion of
40、 the United States east of theRocky Mountains approximately the 104thparallel!.concealed fault: A fault that once ruptured tothe earths surface but that has subsequentlybeen buried by deposition of material atop thesurface trace during the period between sur-face ruptures.coseismic: A term that rela
41、tes an area or oc-currence of a phenomenon to the simultaneousarrival of earthquake waves.epistemic uncertainty: Uncertainty attrib-utable to incomplete knowledge about a phe-nomenon that affects the ability to model it.Epistemic uncertainty is captured by consider-ing a range of model parameters wi
42、thin a givenexpert interpretation or multiple expert inter-pretations each of which is assigned an asso-ciated weight representing statistical confidencein the alternatives. In principle, epistemic un-certainty can be reduced by the accumulationof additional information associated with thephenomenon
43、. The uncertainty in the param-eters of the probability distribution of a ran-dom phenomenon is epistemic.American National Standard ANSI0ANS-2.27-20082fault: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
44、 thetectonic features causing earthquakes have beenidentified. These 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 c
45、rustal stress and strain, and otherevidence. Regions of blind thrust faults are agood example of the latter.hazard curve: Curve that gives the probabil-ity of a certain ground motion parameter usu-ally the peak ground acceleration PGA!, peakground velocityPGV!, or response spectral val-ues# being ex
46、ceeded. Hazard curves are gener-ally generated for periods of exposure of oneyear, and they give annual probabilities ofexceedance.Holocene: The geologic epoch referring to aperiod of time between the present and approx-imately 10000 years before present. Applied torocks or faults, this term indicat
47、es the periodof rock formation or the time of most recentfault slip.intraplate and interplate: Intraplate per-tains to processes within the earths crustalplates, while interplate pertains to processesat the interface between the plates.kernel density: Kernel density estimation isa nonparametric appr
48、oach to defining a prob-ability distribution. It is created by centeringa kernel density function e.g., Gaussian dis-tribution! at each data point, then summingand renormalizing these individual density func-tions to create the composite density function.The smoothness of the final composite density
49、is controlled by the size of the individual ker-nel densities placed at each data point. Kerneldensity estimation is used in a seismic hazardevaluation to smooth the mapped distributionof past earthquakes that is used as a pre-dictor of the spatial distribution for futureearthquakes.limit state: The limiting acceptable deforma-tion, displacement, or stress that a structure,system, or component SSC! may experienceduring or following an earthquake and stillperform its safety function. Four limit statesare identified and used by ANSI0ANS-2.26-2004 1#
