Regulatory Guide 1.60

Design Response Spectra for Seismic Design of Nuclear Power Plants

ML13350A358
Person / Time
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 STANDARDS REGULATORY

GUIDE 1.60 DESIGN RESPONSE.SPECTRA

FOR SEISMIC.DESIGN

OF NUCLEAR POWER PLANTS Ociober 1973 WIDE SA..

A. INTRODUCTION

Criterion

2, "Design Bases for Protection Against Natural Phenoniena," Of 'Appendix A, "General Design Criteria 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'h designed to -withstand.

the' effects of earthquakes.

Proposed Appendix A, "Seistnic and Geologic Siting Criteria,'"to

10 CFR Part .100, "Reactor Site Crinteria,i.

• Would require, in part, that the Safe Shutdown Earthquake (SSE) be defined by response spectra correspoanding

'to the expected maximum ground , acc:elerations..,This guide. describes a. piocedure.. .acceptable:

to the 'AEC ARegulatory staff- for defining S espqnsei spectra for the seismic design of nuclear power 1 kplants. The Adviory Committee on Reactor Safeguards bas been consulted concerning this guide and has concurred in the regulatory position.'

B. DISCUSSION

in o.rder. to approximate the intensity and thereby estimate, 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.

a number of,'required investigations.

It does not, however.giye a -method for 'defining..

the response spectral corresponding to 'tile expected nmaximunt.

ground acceleration" The recorded ground acccleratioihs and response spectra of' past. earthquakes provide a, basis for the rational design of structures to resist earthquakes.

The Design Response Spectra,' .specified for design purposes, can be developed.statistically from.response spectra of.past strong-motion earthquakes (see' reference I).. An See definitions at the end of the guide..extensive study.'has hlcn described by Newmiaik and Blunie in re!ferences I. 2, .and After ieviewing th'se reterenced documents, tilt AE( RegtIu10toiy

'staff has determined as acceptahle tile fI llowicni procedilre

1or'defining the Design RIeslponse Spectra representing the effects of the vibratory

111i00 Otf thi SS[, 1./2 the SS!.', and the Operating Basis Earthquake

(0111) on sites underlain by either rock or sOil deIposits d:l CoVerfinig All frequencies of inter.st.

However, for uliustially soft site..modification to this procedure will.he requited.In this procedure,

• the .configurali6ios of tihe horizonial.

component Design Response Spectra i'm each of the two: mutually perpendicular honizontal axes are shown in Figure 1. of this guide. These sh lpe% agree wilhdeveloped by', Newmnz'k, Blune. and Kapur in reference

1. In Figure 1 tihe ase diagram consists of three parts: the bottom. line:on he left part represents the maximum ground displacement, the bottom line on the right part represents, the maximum a celeration, and ithe middle part depends. on the maximum velocity.

Thle horizontal component Design Response Spectra in Figure I of tids guide correspond'

to a 'maximuin horiznital ground acceleration of 1 .0 g. "rlie maxintum ,ground displacement.

is. uiken.'propportional to the maximum ground accekeration.

and is'set.at

36 inches for'a.ground "acceleratioin of1.tI, 0 g."Thc nunierical values of design displacements, velocities, and accelerations for the horizont-al component Design Response Spectra are obtained by multiplying the corresponding values of the maximum ground displacement and acceleraliol by the factors given in Table I of this guide. Tile displacenient region lines of the Design Response Spectra ame parallel to the maximum ground displacement line and are shown. un lhie left of Figure I. The velocity region lines sl.ope. downward from a. frequency nf 0.25" cps (control point D)'to a. frequency of 2.5 cps (control point C) and are shown at. the 'top. The remainting two sets' of" lines between the frequencies of 2.5 cps and 33 cps (control point A), with a break ata freqtuency cf 9 cps (control USAEC REGULATORY

GUIDES Coplw of publithed guide. may be obtained by request indicating the dwvitant desired 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 lor methods aceptable w the AEC Regulatory tiaff of implemnenting specific parns of Imnorovenmerls in these guldot encouraged and should ae sent to the Secretary the 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 compliance with 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 to the suamnce or omlnmlnuani of a permit or Ilcense by the Commission.

1. Pow" Reactors

• 6. Producst 2. Research and Test Reactots *

7. Transpotation

.3. Fuels and Materials Facilitis

.. 8' Occupational Health Pwwus dsd guides will be revised periodically, in appropriate.

to aecommodate

4. Environmental and Siting " 9. Antitrust Review wornmntS ead to reflect new Inforn-llon or5,swrne. " ..Materials and Plan

t. Protection

10. General F-point W. constituit:

tile acceleration region h ot' the horizontal I)csrgn Response Spectra. Fot frequencies Ihigher than 33 cps. the maximum ground acceleration line represents the Design Response Spectra.The vereial corrrponent I.sign Response Spectra.corrtesponlding to tile IllaxiuIIInIl hIri:minrlal ,rtlnd acceh'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 by antrltiivying tile conrespol.Jing values of" the lrlaxitIniun lihri:mital gr.u mIud moriott (acceleration

= 1.0 g and displacemotw t = 3(N in.) hy the tactors given in Table II of lhi, guide. T"he displacentrertt reliunt lines of tlle Design Re-sponse Spectr;t :are parallel to the mnaxirritimum ground diisplacemtne line and are sMiomin on the left of Figure 2.vhe velocity region lines slope downward f'rom a I'requency t' 0.25 cps (CIICttti l pohlt DI) to :1 fleqtuency oIf 3.5 cps (control point C) and are shown at the top.Titi reniahitnn twIO sets of lines bet weeni th ie frequencies of" 3.5 cps and 3,3 cps Icontrol poini A). withI a break at tile I'reqtlellcv ot Q cps (conitmll point 13). contllitute tIle accelera.li n tetioti o)f' tihe veefical Design Response Spectra. It shliold be noted tltt tre vertical Design Response Spectra values are 2/3 tl.,)se of the horizontal Design Resp-nqt e Spectra for frequencies less than 0.25: I'm Ifrequencies higher tli:m 3.5. tiley are tIle wlhile the ratio varies between 2/3 arid I I'Mr frceuiencies between 0.25 and 3.5. For frequencies higher thtan 33 cps. the Design Response Spectra ftollow tile rrraxirnrnl giound :acceleration lirte.The horizontal antd vertical comnponent Design Respomn:e Spectra irt Figures 1 and 2. respectively, of this guide cirrespond to a tixitimuri horizontal ground acceleratiin of I 1.) e. FFr sites with different values specit'ied b'or the design earthquake.

Ile Design Response Spectra should be linearly sacled Ifrom Fiigures I mrid 2 iti proportion to the specifled tmaximtumn horizmontal ground acceleration.

For sites that ( are relat ivelv close to tile epicenter of :ai expected earthquake or (2) have physical characteristics thfat could significanrtly afT'ct tile spectial pattern (f input motion, such as heing underlain by poor soil deposits.Ilte procedure described above will not apply. Irt these cases, ile D)esign Resixrse Spectra should be developed iitdi\idua.ly ding to thie site characteristics.

C. REGULATORY

POSITION I .Tlie horizontal comtponrent ground 1elsign Response Spectra. without soil-structn tre irtteractiorn effects, of the SSIE, 112 the SSE, Otr the OBE on sites underlain by rock or by soil should he linearly scaled from Figure 12 in propOrtiOrr to tire rnt:ixiruittn lt horizortmal ground acceleration specilied for tIre ear thlquake closen. i Figure I coitrespt;Ids to a tntaxinulti horimrilal ground acceler;tiont ofI 1.t) aind ,,ccomtlpanlyitig displacerternI

of 36 irt.l The applicable multiplicatiot fI'ctors ald corttrol points are given ill Table I. For darmping ratios tot inchludd itt Fi.mrc I or Tible I. at line:tr interpolation should be used.2. The vertical c nmttment ground Design Resporrse Spectta. without soil-stiructure interaction effects, of1 tite SSE, 1/2 tite SSI.E, or the OWI" on sites underlain by rock or hr soil should lie line:irlv scaled fronni Figure 22 ill proportion to tlt illraXilliLlin horizontal grouind acceletafion specified for tile earthlquake chosen. (Figure" is based on a maxitimum

/iri-'iial Sround acceleraiion of 1 .0 g and accomtpanying displacement of 3R in.) The applicable muliiplication I'actors arnd control points are given ill Table II. For dalmping ratios riot incltded irt Figure 2 or Table II, a linear irierpolatiin shiould be used.2Tlhis does nor a pply to sites which It ) ar relalively clno to Ire epicenter ot an expecled eanrthquakc or (21 which have physic.il characteristics thil could significantly affect tite spectral riombinatioin o1" input molion. The D)esign Rcsponse Spectra for such sites irould tie developed on a case-by-case

1srsis.I .0.-2 DEFINITIONS

Response Spectrum means a rlot 'l f lite maxi1mum response (acceleration.

velocity, or displacement)

Of a family of idealized sinoe-degree.of.fiecdomn damped oscillators as a function of natural irequencies (or periods) of the oscillators to a specified vibratory nmotion input a( their supports.

When obtained from a recorded earthquake record, the response spectruin lends to be irregular.

with a mlnihet of peaks and valleys.Design ,,soonse Spectrum is a relatively smototh relationship obtained by analyzing, evaluating.

and statistically combining a number of individual icspi-mse spectra derived from the records of siguificamit past eart hquakes.Maximum (peak) Ground Acceleration specified for a given sito means that value of the acceleiatioa which corecslx)nd-s to zero period in the design response spectra for that site. At zero period lie d&sign response sp-.clra acceleration is identical for all damping "alues and is equal to the maximum (peak) ground acceleration specified for that sit

e. TABLE I HORIZONTAL

DESIGN RESPONSE SPECTRA RELATIVE VALUES OF SPECTRUM AMPLIFICATION

FACTORS FOR CONTROL POINTS SPercent Amplification Factors for Control Points of Acceleration'

2 Displacement'

2 Critical Damping A(33 cls) B(9 cps) C(2.5 cps) D(0.25 cps)0.5 1.0 4.96 5.95 3.20 2.0 1.0 3.54 4.25 2.50 5.0 1.0 2.61 3.13 2.05 7.0 1.0 2.27 2.72 I .88 10.0 1.0 1.90 2.28 1.70'Maximum ,sound displacement is taken proportional to maximum ground acceleration, and is 36 in. for ground acceleration of 1.0 gravity.2Acoeleration and displacement amplification factors are taken from recommendations given in reference I.1.60-3 TA13LE II VERTICAL DESIGN RESPONSE SPECTRA RELATIVE VALUES OF SPECTRUM AMPLIFICATION

FACTORS FOR CONTROL POINTS Percnt Ariplificaiion Factors for Control Points of Criticr'l D spllccmnt

2 Dampring A(33 8(9 cp) C(3.5 cps) D (0.2 5 c1 o.g I .A) 4,%o 5.95.0 1.0 3.54 4.2. I.07 5.0 1.0 2.(11 3.13 1. 37 7.0 I .0 2.27 2.72 I.25 10.0 1.0 I.90 2.2S SMaximum ground displawcement Ik.n proportional to na \imumn gpund acckleraion and is 36 in. fIor cround accelcration tit 1.0 gr.vity.2 Accelera tion amplificalion lactots tilc I ical design rep'.nse slctra are equal 1o iho1c oS f O'h ril(ontia design reslidnwc pretra. %%hercdis displaceient amplification faitorq are 2/3 those hori/tnral dcsign rekponc:rpccira.

Thcsc~. ratiois belwccn tie arnplifiwation f'aciors ofl the t.o dcsicn rc.pons spectra are in agrceenln with those recommetnded in re.l'cretw I, REFERENCES

1. Newmark, N. W.. John A. Blume. and Kanwar K.Kapur. "Design Responsc Spectra for Nuclear Power Plants," ASCE Structural Engineering Nleeting.

San Francisco.

April 2. N. N1. Newmark Consulting Engineering Services. "A Study of' Vertical and Horizontal Earthquake Spectra.*'

Urbana. Illinois.

USAEC Corntra.c No.AT(4'?-5)-26o7.

WASI.1 255. April 1073.3, John A. Blume & Associates, "Recommendations for Shape of Earthquake Response Spectra," San Francisco.

California.

USAEC Contract No.AT(49-5.)-301

1. WASH-1254.

February 19.73.a8 1.60-4

1000 500 200 100>: /\ -,. U S20- -5 5 1110 0.1 0.2 0.5 1 2 5 10 20 50 100 FREQUENCY.

cps FIGURE I. HORIZONTAL

DESIGN RESPONSE SPECTRA -SCALED TO ig HORIZONTAL

GROUND ACCELERATION

a

1000 100 0.' 50 .5 CC 100 50 2i 20 GR UN AC EL RAIO , ',FREQUENC,L

cps ___FIGURE 2. VERTICAL DESIGN RESPONSE SPECTRA-SCALED

TO lg HORIZONTAL

GRCUND ACCELERATION

00