Regulatory Guide 1.60

Design Response Spectra For Seismic Design Of Nuclear Power Plants

ML13350A358
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Issue date:	10/31/1973
From:	US Atomic Energy Commission (AEC)
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RG-1.060
Download: ML13350A358 (6)

t*lAGy. C0\oU.S. ATOMIC ENERGY. COMMISSION:_.;:::; ', rs : DIRECTORATE OF REGULATO RY STANDARDSREGULATORY GUIDE 1.60DESIGN RESPONSE.SPECTRA FOR SEISMIC.DESIGNOF NUCLEAR POWER PLANTSOciober 1973WIDESA..A INTRODUCTIONCriterion 2, "Design Bases for Protection AgainstNatural Phenoniena," Of 'Appendix A, "General DesignCriteria for Nuclear.Power Plants." to 10 CFR Part 50.L'.'icensing of Production and Utilization Facilities."requires, in part, that nuclear power plant structures,syYStems, .,and components important to safety b'hdesigned to -withstand. the' effects of earthquakes.Proposed Appendix A, "Seistnic and Geologic SitingCriteria,'"to :10 CFR Part .100, "Reactor Site Crinteria,i.* Would require, in part, that the Safe ShutdownEarthquake (SSE) be defined by response spectracorrespoanding 'to the expected maximum ground, acc:elerations..,This guide. describes a. piocedure.. .acceptable: to the 'AEC ARegulatory staff- for definingS espqnsei spectra for the seismic design of nuclear power1 kplants. The Adviory Committee on Reactor Safeguardsbas been consulted concerning this guide and hasconcurred in the regulatory position.'B. DISCUSSIONin o.rder. to approximate the intensity and therebyestimate, the maximum :.gr6tund' acceleriationo Of the:.expcted strongesýt..ground 'm'tion,(SsE) for a given site,: pr.oposed -Append*- A, to I 0.'.CFR- Part 100. specifies. anumber of,'required investigations. It does not, however.giye a -method for 'defining.. the response spectralcorresponding to 'tile expected nmaximunt. groundacceleration"The recorded ground acccleratioihs and responsespectra of' past. earthquakes provide a, basis for therational design of structures to resist earthquakes. TheDesign Response Spectra,' .specified for design purposes,can be developed.statistically from.response spectra of.past strong-motion earthquakes (see' reference I).. AnSee definitions at the end of the guide..extensive study.'has hlcn described by Newmiaik andBlunie in re!ferences I. 2, .and After ieviewing th'sereterenced documents, tilt AE( RegtIu10toiy 'staff hasdetermined as acceptahle tile fI llowicni procedilre 1or'defining the Design RIeslponse Spectra representing theeffects of the vibratory 111i00 Otf thi SS[, 1./2 the SS!.',and the Operating Basis Earthquake (0111) on sitesunderlain by either rock or sOil deIposits d:l CoVerfinig Allfrequencies of inter.st. However, for uliustially soft site..modification to this procedure will.he requited.In this procedure,

• the .configurali6ios of tihehorizonial. component Design Response Spectra i'm eachof the two: mutually perpendicular honizontal axes areshown in Figure 1. of this guide. These sh lpe% agree wilhdeveloped by', Newmnz'k, Blune. and Kapur inreference 1. In Figure 1 tihe ase diagram consists ofthree parts: the bottom. line:on he left part representsthe maximum ground displacement, the bottom line onthe right part represents, the maximum a celeration, andithe middle part depends. on the maximum velocity. Thlehorizontal component Design Response Spectra inFigure I of tids guide correspond' to a 'maximuinhoriznital ground acceleration of 1 .0 g. "rlie maxintum,ground displacement. is. uiken.'propportional to themaximum ground accekeration. and is'set.at 36 inchesfor'a.ground "acceleratioin of1.tI, 0 g."Thc nunierical valuesof design displacements, velocities, and accelerations forthe horizont-al component Design Response Spectra areobtained by multiplying the corresponding values of themaximum ground displacement and acceleraliol by thefactors given in Table I of this guide. Tile displacenientregion lines of the Design Response Spectra ame parallelto the maximum ground displacement line and areshown. un lhie left of Figure I. The velocity region linessl.ope. downward from a. frequency nf 0.25" cps (controlpoint D)'to a. frequency of 2.5 cps (control point C) andare shown at. the 'top. The remainting two sets' of" linesbetween the frequencies of 2.5 cps and 33 cps (controlpoint A), with a break ata freqtuency cf 9 cps (controlUSAEC REGULATORY GUIDES Coplw of publithed guide. may be obtained by request indicating the dwvitantdesired to the US. Atomic Energy Commistion. Washinglon. 0,C.. 7D545,ReguLatory Guides ae Issued to. descibe and make arvailable to the public Attention: Director of Regulatory Standards. Comments arml sugpltrinni lormethods aceptable w the AEC Regulatory tiaff of implemnenting specific parns of Imnorovenmerls in these guldot encouraged and should ae sent to the Secretarythe Coammmion's regulations, to delineate techniques used by the staff in of the Comnmiuion, U.S.. Atomic Energy Commision, Washington. D.C. 20545.vellualng specilic problenr'ofa.postulated accidents, or to provide guidance to Attention: Chief. Public Procetlings Staff.liegplcanl. Regulatory Guldes are not tubslltuie' for regulations and compliancewith them Is not required. Methods 'end. olutlont different'from those eat out in The guides are issued on she following ten broad divisions:the.gulde will be acceptable It they provide a basis for the findings requisite tothe suamnce or omlnmlnuani of a permit or Ilcense by the Commission. 1. Pow" Reactors

• 6. Producst2. Research and Test Reactots

• 7. Transpotation.3. Fuels and Materials Facilitis .. 8' Occupational HealthPwwus dsd guides will be revised periodically, in appropriate. to aecommodate 4. Environmental and Siting " 9. Antitrust ReviewwornmntS ead to reflect new Inforn-llon or5,swrne. " ..Materials and Plant.Protection 10. General F-point W. constituit: tile acceleration region h ot' thehorizontal I)csrgn Response Spectra. Fot frequenciesIhigher than 33 cps. the maximum ground accelerationline represents the Design Response Spectra.The vereial corrrponent I.sign Response Spectra.corrtesponlding to tile IllaxiuIIInIl hIri:minrlal ,rtlndacceh'rafioi of I.0 g are slhown in Figure 2 of ih' is guide.The nuneltici al vlues of design displacements. veloci ics.and acceleratiotis inl these spetra are obtained byantrltiivying tile conrespol.Jing values of" the lrlaxitIniunlihri:mital gr.u mIud moriott (acceleration = 1.0 g anddisplacemotw t = 3(N in.) hy the tactors given in Table II oflhi, guide. T"he displacentrertt reliunt lines of tlle DesignRe-sponse Spectr;t :are parallel to the mnaxirritimum grounddiisplacemtne line and are sMiomin on the left of Figure 2.vhe velocity region lines slope downward f'rom aI'requency t' 0.25 cps (CIICttti l pohlt DI) to :1 fleqtuencyoIf 3.5 cps (control point C) and are shown at the top.Titi reniahitnn twIO sets of lines bet weeni th ie frequenciesof" 3.5 cps and 3,3 cps Icontrol poini A). withI a break attile I'reqtlellcv ot Q cps (conitmll point 13). contllitute tIleaccelera.li n tetioti o)f' tihe veefical Design ResponseSpectra. It shliold be noted tltt tre vertical DesignResponse Spectra values are 2/3 tl.,)se of the horizontalDesign Resp-nqt e Spectra for frequencies less than 0.25:I'm Ifrequencies higher tli:m 3.5. tiley are tIle wlhilethe ratio varies between 2/3 arid I I'Mr frceuienciesbetween 0.25 and 3.5. For frequencies higher thtan 33cps. the Design Response Spectra ftollow tile rrraxirnrnlgiound :acceleration lirte.The horizontal antd vertical comnponent DesignRespomn:e Spectra irt Figures 1 and 2. respectively, of thisguide cirrespond to a tixitimuri horizontal groundacceleratiin of I 1.) e. FFr sites with differentvalues specit'ied b'or the design earthquake.Ile Design Response Spectra should be linearly sacledIfrom Fiigures I mrid 2 iti proportion to the specifledtmaximtumn horizmontal ground acceleration. For sites that( are relat ivelv close to tile epicenter of :ai expectedearthquake or (2) have physical characteristics thfatcould significanrtly afT'ct tile spectial pattern (f inputmotion, such as heing underlain by poor soil deposits.Ilte procedure described above will not apply. Irt thesecases, ile D)esign Resixrse Spectra should be developediitdi\idua.ly ding to thie site characteristics.C. REGULATORY POSITIONI .Tlie horizontal comtponrent ground 1elsign ResponseSpectra. without soil-structn tre irtteractiorn effects, of theSSIE, 112 the SSE, Otr the OBE on sites underlain by rockor by soil should he linearly scaled from Figure 12 inpropOrtiOrr to tire rnt:ixiruittn lt horizortmal groundacceleration specilied for tIre ear thlquake closen. i FigureI coitrespt;Ids to a tntaxinulti horimrilal groundacceler;tiont ofI 1.t) aind ,,ccomtlpanlyitig displacerternI of36 irt.l The applicable multiplicatiot fI'ctors ald corttrolpoints are given ill Table I. For darmping ratios totinchludd itt Fi.mrc I or Tible I. at line:tr interpolationshould be used.2. The vertical c nmttment ground Design ResporrseSpectta. without soil-stiructure interaction effects, of1 titeSSE, 1/2 tite SSI.E, or the OWI" on sites underlain by rockor hr soil should lie line:irlv scaled fronni Figure 22 illproportion to tlt illraXilliLlin horizontal grouindacceletafion specified for tile earthlquake chosen. (Figure" is based on a maxitimum /iri-'iial Sround acceleraiionof 1 .0 g and accomtpanying displacement of 3R in.) Theapplicable muliiplication I'actors arnd control points aregiven ill Table II. For dalmping ratios riot incltded irtFigure 2 or Table II, a linear irierpolatiin shiould beused.2Tlhis does nor a pply to sites which It ) ar relalively clnoto Ire epicenter ot an expecled eanrthquakc or (21 which havephysic.il characteristics thil could significantly affect titespectral riombinatioin o1" input molion. The D)esign RcsponseSpectra for such sites irould tie developed on a case-by-case1srsis.I .0.-2 DEFINITIONSResponse Spectrum means a rlot 'l f lite maxi1mumresponse (acceleration. velocity, or displacement) Of afamily of idealized sinoe-degree.of.fiecdomn dampedoscillators as a function of natural irequencies (orperiods) of the oscillators to a specified vibratorynmotion input a( their supports. When obtained from arecorded earthquake record, the response spectruinlends to be irregular. with a mlnihet of peaks andvalleys.Design ,,soonse Spectrum is a relatively smotothrelationship obtained by analyzing, evaluating. andstatistically combining a number of individual icspi-msespectra derived from the records of siguificamit pasteart hquakes.Maximum (peak) Ground Acceleration specified for agiven sito means that value of the acceleiatioa whichcorecslx)nd-s to zero period in the design response spectrafor that site. At zero period lie d&sign response sp-.clraacceleration is identical for all damping "alues and isequal to the maximum (peak) ground accelerationspecified for that site.TABLE IHORIZONTAL DESIGN RESPONSE SPECTRARELATIVE VALUES OF SPECTRUM AMPLIFICATION FACTORSFOR CONTROL POINTSSPercent Amplification Factors for Control Pointsof Acceleration' 2 Displacement' 2CriticalDamping A(33 cls) B(9 cps) C(2.5 cps) D(0.25 cps)0.5 1.0 4.96 5.95 3.202.0 1.0 3.54 4.25 2.505.0 1.0 2.61 3.13 2.057.0 1.0 2.27 2.72 I .8810.0 1.0 1.90 2.28 1.70'Maximum ,sound displacement is taken proportional to maximumground acceleration, and is 36 in. for ground acceleration of 1.0 gravity.2Acoeleration and displacement amplification factors are taken fromrecommendations given in reference I.1.60-3 TA13LE IIVERTICAL DESIGN RESPONSE SPECTRARELATIVE VALUES OF SPECTRUM AMPLIFICATION FACTORSFOR CONTROL POINTSPercnt Ariplificaiion Factors for Control PointsofCriticr'l D spllccmnt 2Dampring A(33 8(9 cp) C(3.5 cps) D (0.2 5 c1o.g I .A) 4,%o 5.95.0 1.0 3.54 4.2. I.075.0 1.0 2.(11 3.13 1. 377.0 I .0 2.27 2.72 I.2510.0 1.0 I.90 2.2SSMaximum ground displawcement Ik.n proportional to na \imumngpund acckleraion and is 36 in. fIor cround accelcration tit 1.0 gr.vity.2 Accelera tion amplificalion lactots tilc I ical design rep'.nseslctra are equal 1o iho1c oS f O'h ril(ontia design reslidnwc pretra. %%hercdisdisplaceient amplification faitorq are 2/3 those hori/tnral dcsign rekponc:rpccira. Thcsc~. ratiois belwccn tie arnplifiwation f'aciors ofl the t.o dcsicnrc.pons spectra are in agrceenln with those recommetnded in re.l'cretw I,REFERENCES1. Newmark, N. W.. John A. Blume. and Kanwar K.Kapur. "Design Responsc Spectra for Nuclear PowerPlants," ASCE Structural Engineering Nleeting. SanFrancisco. April 2. N. N1. Newmark Consulting Engineering Services. "AStudy of' Vertical and Horizontal EarthquakeSpectra.*' Urbana. Illinois. USAEC Corntra.c No.AT(4'?-5)-26o7. WASI.1 255. April 1073.3, John A. Blume & Associates, "Recommendationsfor Shape of Earthquake Response Spectra," SanFrancisco. California. USAEC Contract No.AT(49-5.)-301 1. WASH-1254. February 19.73.a81.60-4 1000500200100>: /\ -,. U S20- -5 511100.1 0.2 0.5 1 2 5 10 20 50 100FREQUENCY. cpsFIGURE I. HORIZONTAL DESIGN RESPONSE SPECTRA -SCALED TO ig HORIZONTALGROUND ACCELERATIONa 10001000.' 50 .5CC100502i 20GR UN AC EL RAIO, ',FREQUENC,L cps ___FIGURE 2. VERTICAL DESIGN RESPONSE SPECTRA-SCALED TO lg HORIZONTALGRCUND ACCELERATION00