Regulatory Guide 1.60

Design Response Spectra for Seismic Design of Nuclear Power Plants

ML003740207
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Issue date:	12/31/1973
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RG-1.60, Rev 1
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Revssion I

December 1973 U.S. ATOMIC ENERGY COMMISSION

REGULATORY GUIDE

DIRECTORATE OF REGULATORY STANDARDS

REGULATORY GUIDE 1.60

DESIGN RESPONSE SPECTRA FOR SEISMIC DESIGN

OF NUCLEAR POWER PLANTS

A. INTRODUCTION

extensive study has been described by Newmark and filurne in references 1, 2, and 3. After reviewing these Criterion 2, "Design Bases for Protection Against referenced documents, the AEC Regulatory staff has t determined as acceptable the following procedure for Natural Phenomena ' of Appendix A. "General Design defining the Design Response Spectta representing the Criteria for Nuclear Power Plants," to 10 CFR Part 50. effects of the vibratory motion of the SSE, 1/2 the SSE,

"Uicensing of Production and Utilization Facilities:" and the Operating Basis Earthquake (OBE) on sites requires, in part, that nuclear power plant structures, underlain by either rock or soil deposits and covering all systems, and components important to safety be frequencies of interest. However, for unusually soft sites, designed to withstand the effects of earthquakes. modification to this procedure will be required.

Proptsed Appendix A, "Seismic and Geologic Siting Criteria." to 10 CFR Part 100, "Reactor Site Criteria," In this procedure, the configurations of the would require, in part, that the Safe Shutdown horizontal component Design Response Spectra for each Eartlhquake (SSE) be defined by response spectra of the two mutually perpendicular horizontal axes are co, responding to the expected maximum ground shown in Figure I of this guide. These shapes agree with aiccelcrations. This guide describes a procedure those developed by Newmark, Blume. and Kapur in acceptable to the AEC Regulatory staff for defining response spectra for the seismic design of nuclear power ,eference 1. In Figure I the base diagram consists of three parts: the bottom line on the left part represents plants. The Adviory Committee on Reactor Safeguards the maximum ground displacement, the bottom line on has been consulted concerning this guide and has concurred in the regulatory position. the right part represents the maximum acceleration, and the middle part depends on the maximum velocit

B. DISCUSSION

horizontal component Design Response Spectra in Figure I of this guide correspond to a maximum In order to approximate the intensity and thereby horizontal rou'nd accehiration of 1.0 g. The maximum ground displacement is taken proportional to the estimate the maximum ground acceleration' of the maximum ground acceleration, and is set at 36 inches expected strongest ground motion (SSE) for a given site, for a ground acceleration of 1.0 g. The numerical values proposed Appendix A to 10 CFR Part 100 specifies a of design displacements, velocities, and accelerations for number of required investigations. It does not. however, the horizontal component Design Response Spectra are give a method for defining 1he response spectral obtained by multiplying the corresponding values of the coriesponding to the expected maximum ground maximum ground displacement and acceleration by the acceleralion.

factors given in Table I of this guide. The displacement region lines of the Design Response Spectra are parallel Tit recorded ground accelerations and response to the maximum ground displacement line and are spectlra of past earthquakes prwvide a basis for the shown on the left of Figure I. The velocity region lines ralional designi of structures to resist earthquakes. The slope downward from a frequency of 0.25 cp' (control Design Response Spectra.' specified for design purposes, point D) to a frequency of 2.5 cps (control point C) and can he developed statistically fromn response spectra of are shown at the top. The remaining two sets of lines past strong-notion earthquakes (see reference I). An between the frequencies of 2.5 cps and 33 cps (control I Sce deftintions at the end of the guide. point A). with a break at a frequency of 9 cps (control U.SAJEC REGULATORY GUIDES Carimis d11rd of Published guindesmamy,be obtained by request ..indictin Ia the US. Atcn* Energy Commission. WVahingR o.

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-Iocantt. RegutOrV Guido owe not sublttuls fr regultions and cowp4m with themi :.not Moaweed. Methods, and Solutins~ different from those matout at The guidnd we aIssed on the f61otlgoaptn brood dit.,.orn he.is tn w11 be cemeptle tIf they t cd Ibais flo ths fiditip equiertO so INeismuwn of sonft~hunce Of 0 p0.915t of be~a by the Cormnkis.on I. P Power tt Asissa Products

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3. Puet and Mevrak Faecilties 8. occuptional Medth Ptbtahed guodasmil b ewited, wetldceltty. as eWoprmo.looccommodem 4. Environmatot and SitPi*t, 1. Antitrust Re 0

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point B). constitut; the acceleration region of the earthquake or (2) have physical characteristics that horizontil Design Response Spectra. For frequencies could significantly affect the spectral pattern of input higher than 33 cps. the maximumnt ground acceleration motion, such as being underlain by poor soil depxosts.

line repfc.ents the Design Rcptu.nw Spectra. the procedure described above will not appl

y. In these

"flih vertical component Design Response Spectra cases, the Design Response Spectra should be developed individually according to the site characteristics.

K

".orresponding to the maximum horizotd ground a'cekreuti's of 1.0 g are shown in Figure 2 of this guid

C. REGULATORY POSITION

The numerical values of design displacements, velocities, and accelerations in these spectra are obtained by 1. The horizontal component ground Design Response multiplying the corresponding values of the maximum Spectra, without soil-structure interaction effects, of the hJri:,ontal ground motion (acceleration = 1.0 g and SSE, 1/2 the SSE. or the OBE on sites underlain by rock displacement = 36 in.) by the factors given in Table II of or by soil should be linearly scaled from Figure I1 in this guide. The displacement region lines of the Design proportion to the maximum horizontal pound Response Spectra are parallel to the maximum ground acceleration specified for the earthquake chosen. (Figure displacement line and are shown on the left of Figure 2. I corresponds to a maximum horizontal ground The velocity region lines slope downward from a acceleration of 1.0 5 and accompanying displacement of frequency of 0.25 cps (control point D) to a frequency 36 in.) The applicable multiplication factors and control of 3.5 cpa (control point C) and are shown at the top. points are gven in Table I. For damping ratios not The remaining two sets of lines between the frequencies included in Figure I or Table I, a linear interpolation of 3.5 cps and 33 cps (control point A), with a break at should be used.

the frcquency of 9 cpa (control point B), constitute the acceleration region of the vertical Design Response 2. The vertical component ground Design Response Spectra. It should be noted that the vertical Design Spectra, without soil-structure interaction effects, of the Respunse Spectra values are 2/3 those of the horizontal SSE. 1/2 the SSE, or the OBE on sites underlain by rock D'esiln Response Spectra for frequencies less than 0.25; or by soil should be linearly scaled from Figure 22 in for frequencies lugher than 3.5, they are the same, while proportion to the maximum horizontal grouMd the ratio varies between 2/3 and I for frequencies acceleration specified for the earthquake chosen. (Figure between 0.25 and 3.5. For frequencies higher than 33 2 is based on a maximum hw algm d acdcrajn cpM. the Design Response Spectra follow the maximum of 1.0 g and accompanying displacement of 36 in.) The pound acceleration line. applicable multiplication factors and control points are given in Table 11. For damping ratios not included in The horizontal and vertical component Design Figure 2 or Table 11, a linear interpolation should be Response Spectra in Figures I and 2, respectively, of this used.

guide correspond to a maximum horizontal ground acceleration of 1.0 .* For sites with different acceleration values specified for the design earthquake, 'This does not apply to sites which (1) an relatively com the Design Response Spectra should be linearly scaled to the epcenter of an expected earthquake of (2) which haie from Figures I and 2 in proportion to the specified physical characteristlca that couMd nifcantly affect the spectral ,rmbinatia of input motion. The Desip Respuotn maximum horizontal pound acceleration. For sites that Spectra for such sites should be developed on a cam-by-cam (I) are relatively close to the epicenter of an expected

1.60.2

DEFINITIONS

I relationship obtained by analyzing. evaluating, and Respone Spectrum mcans a plot of the maximum statistically combining a number of individual response response (acceleration. velocity. or displacemnct) of a spectra derived from the records of significant past family of idealized single-depee-of-fieekrcn damped earthquakes.

oscillators as a function of natural frequencies (oi periods) of the oscillators to a specified vibratory Maximum (peak) Ground Accderatio specified for a motion input at their supports. When obtained from a given site means that value of the acceleration which recorded earthquake record, the. response spectrurr corresponds to zero period in the design resporse spectra tends to be irregular, with a number of peaks ane for that site. At zero period the design response spectra valleys. acceleration is identical for all damping values and is equal to the maximum (peak) gpound acceleration Spectrum is a relatively smoot) I specified for that site.

Design Resp..

TABLE I

HORIZONTAL DESIGN RESPONSE SPECTRA

RELATIVE VALUES OF SPECTRUM AMPLIFICATION FACTORS

FOR CONTROL POINTS

Aenplificton Factors for Control Points of Acmalation" ' OiqImnment

Omanw0n A(33 qxl B(9 qx) C42.5 cpd W)(0.2S qchI

0.5 1.0 4.96 5.95 3.20

2.0 1.0 3.54 4.25 2.50

S.0 1.0 2.61 3.13 2.05

7.0 1.0 2.27 2.72 1A88

10.0 1.0 1.90 2.28 1.70

Maximum gound disyacament is taken proportional to matmwm ground accelciation, and Is 36 In. for pround acceleration of 1.0 gravity.

sAbotimtion and displacement anplifkztion factor are taken from gecoiunmastions Stan in teforence 1.

1.60-3

VERTICAL DESIGN RESPONSE SPECTRA

RELATIVE VALUES OF SPECTRUM AMPLIFICATION FACTORS

FOR CONTROL POINTS

Perosnt Amplrification Fcitors for Control Points Critlcal Acooeratioo' 2 s ai Daf*ping A(33 cps) 8(9 cps) C13.5 cm) D(0.25 cps)

0.5 1.0 4.96 5.67' 2.13

2.0 1.0 3.54 4.05 1.67

5.0 .0 2.61 2.98 1.37

7.0 1.0 2.27 2.59 1.25

10.0 1.0 1.90 2.17 1.13

'Maximum ground dispilacbment is taken proportional to maximum gound acceleration and is 36 in. ftw ground acceleration of 1.0 gravity.

s Acceleration amplhllation factors for the vcfti'al design response spectra arc equal to those for horizontal design re.sponse spcctra at a given frequency. whereas dixplacement ampltfcation f'actms are 2/3 those rot hod znnlal design response spectra. These ratios between the amplification factor for the two desia response spectra are In agreement with thou recommended n rceference I.

3Tbew values were changed to nake thb tabl consittsnt with the dis.

cussim of vertical cnmponents in Section B of this guide.

REFERENCES

I. Newnark. N. M.. John A. Blume. and Kanwar K.

Kapur, "Design Response Spectra for Nuclear Power Spectra," Urbana, Illinois, USAEC Contract No.

AT(49-$)-2667, WASH-1 255, April 197

3. K

Plants," ASCE Structural Engineering Meeting, Sin Francisco. April 1973. 3. John A. Blume & Associates, "Recommendations for Shape of Earthquake Response Spectra," San

2. N. M. Newmark Consulting Engineering Services, "A Francisco, California, USAEC Contract No.

Study of Vertical SW- Horizontal Earthquake AT(49-$)-301 I. WASH-1254. February 1973.

1.604

0.1 02 0.s 1 2 5 10 2D 50 100

FRr WUENCY. cps FIGURE 1. HORIZONTAL DESIGN RESPONSE SPECTRA - SCALED TO 1g HORIZONTAL

GROUND ACCELERATION

1000X

500

010e

4p I5

0.1 0D2 0. 1 2 5 10 20 50 100

FREOUENCY. cp, FIGURE 2. VERTICAL DESIGN RESPONSE SPECTRA - SCALED TO ig HORIZONTAL

GROUND ACCELERATION

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