SVL 1 1 1978
)%%RANDY Rm: J. F. Stole, Dfef, Lfght '>later Reactors Branch Ho 1 Ofvfsfon qf Project Management
FROM: 0 P. A11fsew Project. Manager Lfght Mater Reactors Branch ih. 1 Dfvfsfon of Project Management
SGMECT: DIABLO %NON SEISMIC DESIGN
The enclosed aaterfa1 ms received from the Mvfsory Coaeftwe oa Reactor Safeguards (ACRS) fa. connectfoa fifth the Diablo Canyaa Subcoamfttea aaetfng of June 14, 1978 and June 15, 1978. It fnciudes the follmrlng types of materfal related to Mablo Canyon sefsmfc design: (1) ACRS consultant reports, (2) commnfcatfons received fren the pub1fc, and (3) ACBS project status report. The purpose of this memorandum is to provide De materfaI to the public document reams anct the parties.
681 lysi SlLne OtlC Algso~ Q1/Ol~ p 0. P. A11fson, Project Manager Light Mater Reactors Branch ih. 1 Gfvfsfoa of Project Management inc1 osures: As Stated cc- See flext Page 0:stributicn: LDDavis LMo 01 cil RGoddard HRC POR Local POR OPA'.lison JCSTEPP RHofmann RDenise JFStolz P/assallo JOevine - USGS NHe:imark - U of Ill. MHall - U o I',l. JTourtellotte
arncrM OPM'L'R V~1 sugeaec W OPA11 Ahn:yn ogl....~.,Q...,.l.7s >+HflH4 1IAaeagggg C FOSbC 318 (974) NRCX 0240 *V4$ e 4OVOtN'NNt OttlCO fl
0 Pacific Gas & Electric Company -2- July 11, 1978
Pacific Gas & Electric Company ATTN: Hr. John C. Horrissey Vice President & General Counsel 77 Beale Street San Francisco, California 94106
Philip A. Crane, Jr., Esq. Pacific Gas & Llectric Company 77 Beale Street San Francisco, California 94106
Janice E. Kerr, Esq.
California Public Utilities Commission'50 HcAllister Street San Francisco, California 94102 Hr. Frederick Eissler, President Scenic Shoreline Preservation Conference, inc. 4623 More Mesa Drive Santa Barbara, California 93105
Hs. Elizabeth E. Apfelberg 1415 Cazadero San Luis Obispo, California 93401 Hs. Sandra A. Silver Hr. Gordon A. Silver 425 Luneta Drive San Luis Obispo, California 93401
Paul C. Valentine, Esq. 321 Lytton Avenue Palo Alto, California 94302
Yale I. Jones, Esq. 19th Floor 100 Van Ness Avenue San Francisco, California 94'l02
Mr. R. C. Hartin California Division of Hines and Geology 107 South Broadway, Room 1065 Los Angeles, California 90012 f I,, h ~ I
I' uo.iTcD svnrv,s NUCLI:AA f3EGULA'I'OBY COf.)fiVlfS)SlON novisonv'ov«iuTTi June 13, 1978 E. G. Case, Of'fice of Nuclear ffe<~ctor Regulation If, S. I3oyd, Div. of Project !!anaaement R. J. !!attson, Div. of Systeois Safety II. Denton, Div. ot Site Safety I'< Env. Analysis TRAtfSHITTAL OF I!RITTEI'I Sl'ATF(IEI'IT RECEI'/ED FROl1 TIIL PUI3LIC I3Y THE ACRS The attached:written statement vas subiiiitted by David S. Fleiscfwl;ei iiith 3 attacliio f J. (:. hc!'.inley, Chic ~ Project Reviei ffr tJ i DAVLDS. FLEISCHAI(ER /irro«~Ex~) L~)v Sv)vx 500 102515))r Sxinz.,'. WA5nlNCTO' (. (202) 83340",O June 9, 1978 Dr. Cheste)'iess, Chairperson Diablo Canyon Subcommitt:ee Nuclear Regulatory Commission I'!dvisovy Committee on Reactor Safeguards 'tlasl)ing ton, D. C. 20555 Dear Dv. Siess: I am )vri ting on behal f of'he Intervonors in the Diablo Canyo)) operat:ing license proceeding. On June 14th and 15th the suhcom)nittee;)i ll meet to consider presentations by the Huclea. llegul<)to) y Co))))))ission Staff (" the Staff" ) and Pacific Gas and Elect'ric Con)pany ("Applicant" ) regarding the adequacy of~ Di l o) the ) easons set ou t bein);, thQ Intervenors respect- fully request the ACRS to reject any request to approve the SeiSmiC deSign Cri te) ia. adOp'ted fo) ) eeV<) i))at)On Ol tO CO)n)))i t to the discvet:ion tl)Q ) esolution o'I'he "outs tandi))g i:iQ)1)s . App) oval of'hQ design cvi teria adopt Q(l for reevaluat:ion . i s not mevi t ed unti 1 t hQ S ta ff a))d/or t'ppl i ca)) t have jus t i i ed critical assumptions in thoiv analysis. This is pa) ticula) ly impo) tant because the net: effect of each of t.hesQ assumptions is to reduce thQ seismic design limi ts of the facility. Hei tho). tl)e Staff nor thQ Applicant l)av«p) ovide d an adequate basis fo) select:ir)g an "adjustment; constant fov effectivenes.," Qq))ivale))t to 0.65 to ve(l)lcQ t'0 .75g he t'a accol Q) a tion used as t hQ ze) o pe) iod 1 in)i t fo). t hQ cilitles'ircul dosign ) esl)onsQ spQ('t) a. 1'he U.S. G(.ol ogicnl Survey av t)/2 concl!IdQs tllrlt. in t hQ )loat fiol (l, thQ Peak a ecol Q ) r1t:io)) to bQ expected, o)) avcvagQ, and covvespo))di))g to a 7. rz 'I Dr. Chester Si ess, Chairperson June 9, 1978 Page Two magnitude earihquake, is 1.15g. The Staff and the Applicant apparently accept tllat conclusion, but proceed to apply tl)e "adjustment constant" to reduce the acceleration value to .75g, llovIhere in the St a ff and Appl i can t presentation i s i t demonstrated tliat tliere exists in tlie scientific communi ty general, agreement for selection of 0.65 as an adjustment constairt" to reduce peak acceleration values. In fact, tfic Applicant adl))its t!iat no such agreement exists. 1/ Furthermore, 10 C.F.R.5 100, App. A requires that the zero period limit foi desig« i'esponsv,. spec ti a correspond to peak accelerations. In vie); of this i egulatoi'y requirement and tile adl.)i ssion tlia t tliere is no gene).al agreement on selection of "adjustment cori s tants," addi tional justification is needed for shav i ng tile pe ak in t:his case. 2/ Second, neither the Staff nor tlie Applicant have. provided data that justifies the high damping values used in the reanalysis. Admi ttedly, tlie Regulatory Guides permi t thr. use of damping values equi,ale»I: to 7! - tile value used in the ) eevaluatioil. llo)"ever, it ma iles no sense to involie the Regulatory Guides as justification for usiiig high damping values, (as the Staff has done i)ere) in lieu of producing sci enti fi c da ta to jus ti fy Use of tliese values. Thi s i s particulai ly the case ivher e, as i)ere, the faci'1 ity is sited i'n a zone of high seismic i.isl:. 3/ Addi tiona 1'ata to justi fy the use of tile 7l'amping values should be requii ed, and the Staff slioul d be requii.cd to analyze the consequences of actual dai!lplilg values beiiig lo)(e) tlian tliose assui!ied. Tllird, tlie tau-effect analysis 1 s bclsed oil Urli eal 1 st'I c assu)))i) tions. Tliis analys i s assumes tl)a t the sti Uctul e foundation is rigid, and it is not. flei the> L'he Staff noi tlie Applicant i)ave demonstrated tlie applicability of tau to 1/ FSAR, Amendment 50, Vnlur)e III, App. D, at 11.12. 2/ 'Gene) ally, Staf f'ractice is to use tlic mcaii ot the peak acceleration as the zero period limit for tlie l' d e s i g il response spectra . T li e s c 1 e c t i o ii o 1 e s s e r value here is an evccptioii to tliat practice, 3/ llse of sucii i)i gii values represents a del)artu) c from r)o) mal Staf f pI"acticc. I ~ I Or. Chester Siess, Chair person June 9, 1978 Page Three rock foundations. The analysis assumes that seismic waves approach from a horizontal direction and I'ails to cons'ldev the consequence oF the seismic wave impact from an the angle of wave impact in tire near field. upward'ngle, In addi- tion, the analysis fails to consider adequately the torsional effects on the foundat ion. There is little discussion of the tau-effect in the scientific literature. Ttrus, the theory has yet to be ex- posed to the cri ticism of the scienti fic community. There is little reason to adopt this appr oach when better methodo- logies are «vailable. Specifically, .the 3-dimension<,l soil- structuve interaction metlrodol ogy should be applied to the design of, ttris facility. Corrrputev programs, such as the CLASSI program, are readily available f'r such analysis. Use of such programs would elirainate the need to rely on the questionable tau-effect approach. 4/ I I . ~ lie turrr r>ext to tire resolution of outstanding issues relating to the design of Category I struc tures, systems and c'omponents. The Staff is expected to request that these matters be corrrrrri tted t o i ts disc> etion. "lre Intervenor's are opposed to an l 4/ See, fl. D. Tv i funac, COtlllEl'[TS Or<'E I SllI C t)ES I Gtl LEVLLS FOR l)17iOLO Ch:lVOH SITE Ill CALIFORlllh, hpr.il, 1978. 'I , ~ ' I Dr. Ches ter Siess, Chairperson June 9, 1978 Page Four represent „approximately forty-six (46) individual outs tand ing items, as cited elsewhere in the SER, Supp. 7. 5/ Second, of. the open items, many are critical to the safe operation and/or shutdo;:n of the facility. These include: Containment Interior Structure - discussed at p. 3-28; Intake Structure - discussed at p. 3-34; Turbine Building - discussecl at p. 3-39 and 3-40; Reactor Coolant System - discussed at p. 3-48; Flectrical E Emergency Core Cooling System - d iscussed at p. 6-6. Third, in its analysis the Staff has depavted from Regulatory G«ide proceduves and/or Staff practice and c«stom. i'it p. 3-22 and 3 23, the Staf f candidly admits that "/T/he general methods of analysis used by the In addition, still outstanding a) e analyses applying the Regulatory Guide 1.92 method of combin'ing > esponses to 5/ Section 3.8, p.'-45 and 3-46, 22 items; Section 3.9, p. 3 and 3-70, 17 items; Section 3.10, p. 3-75, 6 items; Sec tio'- 6.3, p.6-6, 1 item. l' l(a Dr. Ciics tcr Siess, Ct)airperson June 9, 1978 Page Five the reactor coolant system main loops; 6/ the support capacities for reactor coolant systems. branch piping; 7/ the other Category I pipiiig.8/ Also, the seism'ic qual i'l icatio'n methods employed in sa fety-re 1 a ted el ec tr i ca 1 ins trume»ta t ion and cont vol eq(ii p- mei)t does not include the aging vequ-'ve»>cnts and other (,c»e) a i enviro»mental qualification recomme»(lations thai are ref~lected in Regulatory Guide 1.100. 9/ III.. Apavt f rod> the matte> s >'ai sed in pvcccding -paragraph we would like to di>'ect your attention to two other mattei s, First, there is a case to be made that a 7.5 Hagnitudc earth- quake doc. not represent the maximu>a earthquake potential o tl>e llosgvi-Sai) Grcqovio faul t. The case is suramavized in the attached letter from Dr. El i R. Sil ve> to Drs. iicl'eown a»d Devine. 10/ The recent wo>'k of D) s. R. K. Harl'r)d i~i. G. Ho»illa bolster this case.l 1/ This wo>.k coiicludes th<.t the methods genei.ally used to estimate eai tliq>iake magnitudes f) om faul t 1engtl>s, yield esti»>a tcs of the average size, ra the> ti>a" the maximu»> size . event which could occu) o>l a fault.12/ 6/ SER, Supp. 7, at 3-69. 7/ Ibid. 0/ Ibid. 9/ Ibid, at 3-72. 10/ See, Attachment l. 11/ Scc, R t tac l»»en t 2. 12/ lic a)'e aware ttiat ma»y scientists are of'- tlic opinio» tli'it a l g)ii>icilt of whc thcl" thc Sa f c Sh>i id Q>li) Ea > tl>q>>a k(.'" SSE ) be Hag!)i t udc 7, 7, 5 o>. 8, is of scco»(la> y i»>i)o> tancc. (Sr f>'o») i>a D(.v lil('. Rttacl»»(.»t 3, Lcttc>. F.R. Hci:(.(»I» ai)(l J. 1:('l 'i,R. Sil v(.v, da tc(l Rpri1 13, 197D) . ffcv(.» ti)cl (iss, s i»(;< cas('a» b(. »;adc f'o>. or> SS(:. ii;)(,»i f (i(l(. 7.!i, 'i t is p<» t. icii oii»' t(' s ..>i().", ) (c(>(>»i z(a(I 'lv <'> i 1 l'o l>(> ti'oiihl ( .'~»:,e '>pi>i ' a ~ ~ < ~ ~ ~ ~ I ~ I s ~ ~ I a I) ~ as I < at ~ ~ \ ~ s ~ I ~ ~ ~ ~ ~ Sa ra I ~ ~ ~ ~ I afar'll rhlla I,s ~ ~ I I ~ 4 Jl'r. Chester ss, Chai.rperson June 9, 1978 . Page Six Second, the Staf f and Appl icant sel ec tion of an Operating Basis Earthqual;e ("OBE") corresponding to a peak acceleration oi', .20g contravenes the'xpvess language of 10 C.F.R. 5100, App. A. The maximum vibratory gvound acceleration of the Operating Basis Earthqual;e shall be at least one-half the maximum vihvatory ground acceleration of the Safe Shutdown Ea! t hqu a I;e. 13/ Sel ection of an OBE equivalent to one-hal f (-':) the SSE pvovides an impo! tant ma! gin of safety for the faci I i tv. El imina ting thi s ve(iui vement !!!ay mal:e sense in sei sr IV. In conc 1 u s ion, the Intervenor's subr 13/ 10 C.I .R. 9100, Rpp. A Y(a)(2). I f ~ (I ~ II k I I ,0 Dr. Chester Siess, Chairperson June 9, 1970 Page Seven DAYID S. FLE ISCHAKER 1Q25 Fi f'teenth Street, H. l<. Suite 602 Hashi ng ton, D. C. 20005 Attorneys For Intervenors SCEHIC SHORELINES PRES ERVAT IO!l COi'f" SAN LUIS OBISPO llOTHERS FOR PEACE ECOLOGY AU'I I 0('l CLUB SAllORA A. SILYER JOllll J. FORSTER ~ '. !!'g(!.Yir~i'0 n (G~(C:i~:,~':2iy By: .("'avid s. ! iaiscaal:er t t fl t ' ~ C!II'7., CAl.ll'OI Frank A. Hcl'.eo';n JarAes F. Dev j.ne U. S, G(>o].<.~,",i ca]. Survey Iles( on > v i) gi. P.ec(;<3(:].y ]: I!as as)ce(l by ].ai!yers at: t:he C(.ntcr for T.ai! in t:hc Pl!!) .i.c XrIL'c).-cst L'o e~v.ii!3.»c thc various scism).c saic(-.y )) l Laillillg t:o t:he l)i."..b].0 C I)yolk pot!cr p]. nt ~ 'oc»(i:(.nts Usua] tile I. < c 1. voi.cc at c)].1 iO'. call > I '1 0(IL Fran): /. Ifc}'cow» PAf.,c 2 3ame F. Devine Febriiary 27, 1()78 « f).r t: pro))].en) i" outhward conti»L)c)tion of: tive San G)..c, orio iault. Greene. An(l oLhcr inLc'.rpLct: Lhe Palo Colorado Lo be t: he southern e .tension Q.C the San Grcpor3.0. 'I'<"0 line.; of evidence ar<.uc «(.,«inst t )is as the m«jor co»neet:ion. Steve Gl.ail lvil G lilapf)ill(< 3.'ndicA Les t:)lc SLlr f:«LllL shows a )ilol c 3.»tense crusli zone, ind„.cative of major f!AL)lting, «r)d vc);y di similar roc)< I:yf . s a.cios. thc f'au].L. The J.';i].o (.'L J.o).AL)( in contr;i t is a narrow zone w3,t)3 rathex simi.l.«L rocics 0» either side. /)iso, an HS t))esic; by tlnodson (1973) at t)3c iiaval PosL Grad. Schoo'J., involvin< 'dct:ailcd bottom <;r«viL'; studies shoi' a pronouncecJ grctvit:y gradient 022 the coasL (sce enclosed f3.guxc) w!ii.ch wou].d al].ow a major f«L)].t conne(:t:ion to c it:hcr t:)I Scr rA )ii1]. or Sur f'v()l ( G but: noL to Lhc palo Coloracio. This doesn': )))e«» the Palo Color«do J. Lhi n)c (.1'ie Bva'3. lab J.c cia ta <31 c liloG t: coll!)«3 s L'e lit wi (:)1 ('llc Sall Cre.'QL 3.Q ''I()G>1. 3. as A con (:i!)L!QL)s Oc)L) 1 L <'.nile i). Qi)) about: Pt. /)ri',L)(:.1].0 t:o SAn F).ancj.sco, a le))rt)3 cf." 'ioO lc))). I)ow about of i c.t? I fi) 't su(. < st,ed SO-90 I:i) Qn.ti>c S«n G).c Qr. o ba.,ed on QJ:f;sc)t ))a..cm»t tc.rranc, cc n(xol.lc.(J by of.'Csh()rc~ p): ivity (I«t: i. Thi.. interpret:at3.0)«)as b'ise(l o)x cons j.()erin< tl.c SQ» Gl. ef'Or3. ) t0 0 f f sc'.t tile,.',1. 'ii)Lt::Lc I'r incise:ln coil(:.(et ac. Vf Sur nor t)]war<1 I:0 i. (:G p).-01):)b] e ] 0<:At: J on L))') t:hc )c«<.G(.: s i.d() ni: t:h IP 0 Fra»k A . Hc}:eo(')n Pa<;c 3 Ja!ncs F. ))evine February 27, 1978 S( j ll. these data are not nc ar] y as ti(',}!(: a.. Lhc of:f:sct shorclj.ne covered bv (veil-datecl,;n(l chemic'!].l.y odd ].avas LhaL are offset by t:hc San A»drcas, pivj.»p c.mac t picrci»g point:», or Lhe morc general buL still tif!h(:ly contro].1(!d 8 tra tip r..phi c arc sc! en i C thc ~an An(l) cas i)Q1 . 90% «Ilder Hat cl., T cloi!0L' t ~ I n! Qnclosjn~ a co py o 1 the Grah«I Hhat cloe 8 t his mean in t:crms o f c).-ii«Lal. pl.;!Le bounciar jc 8 . Al'.d1 X L j~ Onc 'OLhc!r int(!rest j.»;.; ObservaLion LhaL only T. seem to have I!a(IQ is tha L' h- 1,".()so» re po) L "o f: thc 1906 SF e'l' 1'(1ual c report:8 measu'd o Fina].].y, i hat ab<)i!L Lhc po.':.".ibi].'j.t:y o . a n)lI <",»i tIIdc 8 'n! car t:h()U(II(c on t:hc S I» GI:0/;ol:i.o -))0!'<:,ri ~ I su) <'ou 'l l(,rce t:ha L 3. f: l00 I:nl j. 8 «CC('pt('.<) as t:hc f , ~ ~ Franlc A. Hcl',coffin Pape Ja)nes F. Devine Febr t) at leasL. Lhe cnt re San Andre.as faL)lt sys(:Qttt. t c bc; .ncl T.a joie (3977) repor t: a 1!oloc:ene sl.i p rat c o f 1,6 cni/yr o» t:he S;-tt> Grec orio faul t.'nd Bur ford ). Qpo). ts . up t.:o 3. 3 c)n/y). geodet:i.c slip on the cen tral Ca ifnrni t p'tr L o f t:hc S-:in Ai)dreas, in t:he re1,.,ion where sLrai. ) prc'.sun)al>ly is»o L acctttnL)l'.t tint;. Thus iie mi.'<.Itt (ts vne a sl ip ra te ot) t:Ite Sa') Grcgnr jo-11(>s",).i I)et ween .'I. 1. 6 and 3 cm/yr.. It woL)l.d t al;e > Lhcrc fr)re, b(. Lwcc'» 217 and 33.2 year" to accumula t:e .)00 tn o» tltis * ul t . X f we we)-e t:o predic L L'hi .. < ar th<1 L. Does tl)is si tL)ation llave a» 'now» ()ouljtc) p<>l Ls? Can you pet lar<>'«qLtal(cs o» sLow !novi.n~ sLril;e slip 1aulLs . !iow == about: Lhe 1900 c.(tl. LIi(lit~ kc (I') 8 . 6) o)'t (:I'ic Sal't Scl) as t.).an fault: just: off the co') st of Ven izL)el a»car Caracas? Sl j ) rate s there la.o., t p)".oh So, i here do i go f).gin he). e? Cl.ea)-.3.y cr j. tical c!a.tv. wc). Q not av "i.lable to you i ) ea).-3.y 1976 t:ha t ar ai a:!.3.al)lc now. Scj.sn:oloI',is ts m";y have 0 I:hcr reasons fo:. (Ic>L:.bt).n~> the po! Si- bi.lity o f a )na~ As a» aside X see a» inc)c!dib'1 e a»al ysi s l>y S . U. Sn)i tlt in Appendix Dllh, Vol.L!!nc 3 of i.h(! 1?(>Bi'. rc!por t:. Usit)!; his to).-ic eis!ni ci. I:y fro)n 1930 t.o 19 75 Sn i. Lli co!n!>Lit:c ln~ >l '- 3. 72-0. 92 H, where N is no . o f c.a). th(1 tiakcs pc.r y<."ir in I:hc ). e.) j.o» i)it:h n)dg»it:udc greater t:han n). (,(Iu:tl t:o Lh'it: n C 1,! . '3. f st ask how 0 fLe)i 'l n):.)P)'li. L'udc 7 . 3 c".!). I:h(lual(c w i.3.3. occur 1:I>c c'.(Ii)a t: j.or> t:el.ls us o»ce Qve).y 1000 years'. Jsn': j.t: ncld L».'t't. 3 yc".i). s p) j.o). Lo L'hc daL'a 1)as!'. L'hc 3.000 yc;tr e Hit..i.l.e t:1)c! Qvj.(IQ»cc l '«', >t) t:lj»c'.d her<'.s»'>(: pron 1.'? t: (t pot:c.»t:.I;) 1 f'oL )>>;tt',t)i.t:ttdc. 8 car Lt> FranlcJamais A. l'cKeoc)n Pape 5 l.' De v3. ne 1'eliruary 27, l978 from eonsicleraCion, 'l'he ~"ho).e quesCion of: maximum poLent:ial. c:ar Lliquafcc. ancl safe shuLclo l'lit:h l)es t: ). ep„ards ) Eli A. Silver El(S: .".h Ene 1.o sur e s I ~'f '1 l.oboe 24 0 1 ? I 2'0 f1 foal f 30'0 30 0 2 L—~~ kn! 1 1 10 36 2a 32 34 31 :lO ..0 -20' 20 12 13 13 w.z "0 $1 122 00 " I I "c .;:n,aa 'k,n k>l!u>'n I6. Cl'h III"I viln>linn for fl>n Cni't incnl;;I Hh< If nn IA0 t UI(+4( CV CCPVSK CVK 51 rrg r rr( AVSI((:V 0V CAS(V(K 0'"(( tv(''v( t Crsv Atrr I( ( I (()V vs ~ ~ (AS SAV I Ck-:—'"". Crsr lit+A(rv — YACC IW, 0 )sr ~ ' cccv" ~ —> - r -rrrc( -N .II~~~ 50: ~ ~.rt I 0- Jj C / ~ I(~ AVf+A AI CC trsl CAS'» t ~ Crvr """~ "" ~ I . (Vr ~ t CLSC ~ 0/ COVIIV( VII( ' ~ (IrrII( V 'VI (r 0 100 51 ... ~ ''" I VI(4 I(AS 5r VV I ~ I I 5 ~ 5( I 't't ~ '\ ~ 4G l22'2I'C pro 'I ~ I Glen:!.'c ri4.c Frcncssccn n4gc ' acsi,n n i'Qs 'c Fcc" R ''J ,%,:;:.~ a 4 Pr (ceno Bcsen / ,4 . ~ D«5 Op COJVTlldc'aVT«I '.... ~, Op ~, 2( fGOKnoactct 30'25'7& l2r~ 3C~ ~ 5 '5 ~ II ~ ( m . ~ The .")n Gref,n).io-llo..;;ri. 1ault: 7o»e: An Ovcrvic« f li A. Si.iver Ear th Science: 13t.!:». d lir)ivcrsity oC Cali fo). ni.a Santa Cr()z, CA 9506'> The Sa» Grego).-io-)losg).i. fa<)lt zone is part oC the Lart cr San /«idreas fault. systetn in (:aliCorni;) t:hat; Corms t:hc major locus of: shear due I:o movcn)cnt bet«ecn tl)e PaciCic and Nort}) A!»erican p)aLes. An cnb);nious an)ount oC eCfort has been and is presently beinf; devoLed to study oC t: he San Andrea C.ult: i.t'lC, and in recent ye"). s dc(:ailed qu.-.nti('ive 1",no«lcdf;c oC n( set !iistol:y, rei...wici';y, and pl.rse it-dly movemant har, 'j.ncrca ed dran:at ideally (see Cor esca;nplc Kovacl) and Nur, 1973; i C)-o«ell ) 1975) Dicl;in 'o;) a).() Gr..nLz, 19(I8) . Th e.(.'nt: oC our. 1'»o«l.cd,",c oC other. Cault oC the San A))drc «s sys(:cm i.s n)uch lesrs con)p].cte, clue in part: to thc lo-."e).- Creqi)ency of: f.rcat earthqua);cs and snallc) oCC et on subsidiary Cau'l.t: (and there Core pc).-1)aps, le .;er intcre. t i.n these Cau).t:s) . 'Another reason n)ay be the loc )tion oC . o'n e of.'l) subsidiary .Gaul t:s e Tl)e San (',l. cfrol. in-1(osP) ', Caul L zone l.s 1!)catcd alo;)" t:hc coa!>Lline sout'h oC Sa» 1'ra»ci: co Cur a lc))<;t:h o C nearly li00 )'n), and n)uch oC it lies ju.,t oP'C.,ho)'r «here it: ).s dhi CCicul(: L'o s Ludy . Ha j o). outs t: .)ndi.n., prob Lcrns o C t:hi.s f.a<)). t zone i.nc 1.udc ') t: he dcLails oC lau 1 t loc t i oil con( in()i 'Ly l)e ( «een (hc S'ul c (;)-c!,o) i() and llos);r i. Cault; sef,~n< nl:s, r ), Csct; 1)- st'n).y r») each cvi dc;)co Po'lol 0('ct)e lnovcn)ellt:!: sin(::<') sin) ( ) ( y 'l,))i'':('cf'.,)nenL', J i( fj j (f 't pcoblests ha e in Gnd their E>cari i)p on Gnalysi.s OC seismic E)aiba).-d Cor. coastal devel.op-)ent: and po|>cx-l)l.ant si t: j.»g. 'jl)Q pap('.rs i.n Ll)is vnl.u;))c i.ere prcscilted Gs part OC a sympo ium on the San C):ef;or).O-HOs< xi fault zone Gt the Coxdil.l.cran s(ction )nc(.tinp OC tl)Q,Geological Socict:y of: A). rica in Sacramento in Ap).i.l., 1.977. Ho t G U. 0 C L)30 s(! pa pcr Gl."c reproduced here out those: Cl.arl-.:-ind E>XGE)b di.SCuSS tE)e (EQLc>ilC(E S(:Xat-.if;)-.GPl..y On Qi.L'he): si(le oC t:Iie SAll C):e<;0!:i.o fault in 3.t:s tyl>e Gxea ~ l'Eleix careful ( OE)serve) Lions of fu))(li:)",cn(:al. stl at;ig'l>hic di Cfe). Qnc(.'s, i).,)l.<< sif,lliCi.cant (liCCQ).en()es in sedj.))'Qntation Gir(l tccL'on'c history on either side 0~ th(. Caul.t. Crab)a)n and Dicl(ir:son usc Lllits Gn(1 otl)c)::Qgional data t.o ).nCQ). up t:0 ].1."> 1;m oC ris'h )>i.t:1) th(! above est iiiiGL'cs Cox C). (.~o). 1 'Ut Lhc San i,o sc<;.))Qnt > tll('los@i i Qstin)ate has bc('n (Et)est:i oned (lie<)i.l.t:on 1977) . 11)1l (thi., vol.l)i[le) 1>). iQCE.y a(E(ll ()sscs thc Q qu( .. Lio»s Al'1(E E)).oposes a pL)l.l. "«1)a). t 0). ) i„'i.n Co). t h(! S''int''l 1'far j a basin 01) silo) (! . 'J'llc (lucst: j. )n OC c(>ntinuity of t:hc .":in C),(:,i,curio-ll()si;))i fnt)l.t'i)n(. 1 0(:i),;u.i nn f()u) p) ()E>E ci)):))'i ') .: pt> i »i: .')i)):, Cape S<») ~ ~ 'I l l„' a ~ a I ~ Hartin, San f>in>aon, an<1 aouth of Point Ba1. !F'ig. 1) . )1>a Point Sur. repio» is discussed in dc'.t:ai.l by Gral)am and Dickinson. Their interpreLatio» that.'he San Qrcgori<) probably connects with the Sur. fault is .,upport:cd by det:aiI.ed Gravity tudies (tloodson, 197 <) and a). t'ucG AQQi»st t p). Q~~ ious GUQ~Pes tio» thaL': he main San (:ref",o). io f:ault trace turn." i.»land south o f Honterey to join the I'alo Colora(lo Ceult (Creen('nd ot:hers 1973) . Ilail (1975) fi r G t "G()gs„."esto pa).-t: of the Hosf,).i fault ro»e (Fi,;, 2) . 'I'hc dc:tai.led connect:ion bet("een tl'.e, IIosvri a»d San Simeon 2'a»its has notbcen establi.shc. an 'en-echelo» offset between these'aul.ts (Hall, 1975; h( Culloch a»d oth!.rs 1977 ) . The Sag Simeon Disci.sion(IIosp):i) .:ey. nt t).-ends of C.;hc)re to the nc)rt:h tc)('a)..d Cape San 1fart;in (Fig. 2) . R(.cc'.»tly f.'low) )eromaf'i)etio data (USGS-Cali". of llin s and C'colo(;y unpubl.i.sh d d..ta) reveal a hip;h eml)3.iL'ude ano'...al,', trendini; »ort:1)west across Cape San Harti)) and . cern to r.c.clui.re th» Ilosp)-.i-Sa)) Simeo» fault eit:her. to be»<1 arou jd Lhe a»os.la ) (F $. o f Cap'. » I iar tin (I!cC))lloclx an(l ot:hc.rs, 1977) t:l)at t:rend., tow<)rd t: he Sur CauI.t: (I'i.f",. 2), 1lcCul1.o(:h «n(l o L'h 'rs (1977)'Lhei). I'if . ?) show a»art:hwest: t:rc.»(Ii»:< fault: weGL'C 1'oi»t SS<)); (I'i<",. 1) which t:hey c x t;Q»(1 Gout tleast w(ll cL) t L'ill('c).0G <'lid !)c I>a L <1 t; j.c) ~ t:l)c Il<)Gp). i «)) inL(.) I>r( t::) t: I o» !'o>.'I.<.l impf.y ,I «i ))ito 1;« I; o f c( nt:i»))i.t:y I>; t;: '.c! n I ~ ) l T I ( tha San Grcpoxio ancl Ho.".>,'xi i'cults in Lhis axon. |lowavcx, Lheir norL'l):)est: t:rcndinp, f()ut.L )nusL eros» a 1)if,h ampliLude mapneLic anomal.y tl)aL'ies p')).al.'l.cl Lo Lhe co'isL (Qiloli) ~ ly bounded by -1.5 nT conLoi)r i» Fi~;. 2) and L'his )nomaly shows no evidence of a c1osscuLL in'>t:rucLiire. The anonal.y al.so L).ends parasol.el t:o Lhe Sur. and lios< ): > Cs)ult:s a»d may be cause(1 by sel penL'ine inLli)sions al.one Ll)(. CaulL. St:):ucLulal ):claLions i)7 Lhis n(.ar.shore area are ()1.>scure(1 by sue f .ce sl(U)pi)lp - (Y>CCull.nch an(l. ot:he).-s L'h(..il Fi <,, 2), an(l T. conclude LhaL'he bul.)'C evidence aL pre.se))L l'avors 0): aL least: a1.70:)s cont:inuii." beL<~een t:he Sur. and Hosl,);i Caul.Ls. The so()Ll)<.rn e:-:Lension of: t: he 11o.,pr.i is a,iso in di!>pu~e ~ licCu3.loci) and o!:he):s (j.or 77) map t: he f:aii)1L'ou~h 0 C. PL. /'.). pu21.7.0, bvL 1!x)mll.L'on cin'd t'"i.'1,. 1.) n(,'h(i:)) (l.9/7), usil)P Plucll t'1'('. sa.')lE! (Ii La, )n,".p it no fa):Ll)e".. ouLli t:lian of>".shole I'oi)7L'al. EiLhel'('.). i siol') ). Ai. e. coil)<"). icak 1)l"(>bl.e>l)s 08 < )ld i)if' f ul. L HiLh appro:'i)>)aLe1.y l.00 lan of l.nt'e Ccnnzoic ). )Ler.al 0>".f:seL. Va=ious soluLions to Lhis plobkem h;.ive be(.n prol)osed in 0).al. co::::"..iini- cat iol'is» i)lcludillp) a bpti(> of; t he fault: int 0 Lhe Tl ansvel se 1 allies '~he):c Llle FloL io)l %>oui.(l b(". t::.)1(cn up in comp). ess').(>n (0 . 4 1. l)>e) 11(Cu11.och> 0)-al co:))))>u)). > 19(/) 11a)))11.L0)) «nd i Li»t > '.97/) or. an of.'f.,(.L of Lhe fau'1.L 1 y (!; '1 13; ).bal let',ioll (J . C). Ailcll 0) ll. Co)l).1 ll ~ 1.9/()) . Qt:is f ac t.o)." Ql(1 (loci)i!)QllLaL).0)1 hob'ev('.). l)oL')eel) 1 el>o). L Ud t re!))ail)s ai) out ., t: in(1il'1)',t'l.'iict.ilr'll. pl (>bi.<."i)1 . c 11010c(.o<'. )))ov<.",))en(:s a). e <;(!1.l. doc())))<.)>( «<'1 f>0): ('li» 8;):) (:):<))ro)-) o F I vo)unto), nnd: Ludios of: soi srnici cy conCirni chc pro,:onc-dny acLiviLy on boLh Lii» )fo.;~;.ri an~1 San Grcporio sef:;nlcnL's (Ga~)ihxop, 1975 and L'his voLurne) . This infortnat:ion is criLicaL to any pLanncd develofmenL aLong t: he cent:ral. CaLifornia coast bccau;,e Lhe,"."".n Greporio-lfosgri is very nearL" a co" LLinc fauLL ovcx mo L of iL's Len<;tf>. . 'J.'fie San Greporio-lfo "ri appear Lo be Lhe largest of Lhe subsic J:aui.t:s ~)iL'hin iary the .~an I.ncfreas system, bot:h in 1 enact:h and 'ofR'seL-. OLi~'.r 2 iulL'.;, such a t: he ff .y::ard-Ca'J.avexas an.l lkinconada havr Lesser Rc fcr.cnc.cs Ci. Lc(I C);o()cll., J. C. (I:(I.) ) 19/5, San h»(Ireas faul.t: in souLhern California: Ca).ifornia. Division of !tines an(l Geology Special Rcpoi.-L 118> 272 p. Diclcin on, Y. R,, n(I Grant::., A. (!;cls.), 1968, 1'rocec(lings of Lhe conf crenc«on p(.olo~;i.c problcrns of San And".eas fau t sysLm<: Stanfor(I Uni v. Pulis. Geol. Sci. > v. 11, 37') p. QawLhrop, Hilliam, 197.), Seis>micit:y of Lhc cenLral California coas La L reS~i on: U. S. Geol. Survey Op('.n-file RcporL 75-'13~', 87 p. Gr(enc, Ii. G., Tee, P.. Il, N., HcCulloch, D. S., an(1 Drabb, E. E., lr73,, Poult s «»(I ear Lh(lual(e.'n L'he Nontecy Pay ref,ion, C" li.forni.a: U. S. Geol, Survey I lisc. I"ield SLu('y H. P. -518, ll. p, Ilail, C, A, Jr, 1975, S » 'i!eon llosgri f ulL sy L~~, co'sLal Ca'I.ifornia: econo!nic and environmc»Lal iwplicat:j.on.,: Science, v . 190, p. 1? 91-129~i . IlmnilLo», D. II., a»(I Willi!!@ham, C. )i., 1977, lios;ri fault: Ro»Q > s L~ t'ul uc c > alAoullt: of (!isplacc<))e»t:, a»(i rel.(!~ionship t:o s Leuc Lure of tl>c vesL(!rn '1'ranv(.rsc a »~p (': G c 0 1 ~ Soc Alocr . i!1)ls ~ ~ ~k ~ ica hbs xi Lh pl op>1. > v 9 > no > p <)?9, I'ovach, )',. I,, «nd I'ur, hi.)os (I'.(Is . ), 1.97:I, (:onferencc o» I:ccLo»ic I»:olil(!;!.; of t;hc Sa» h»(Ir(.(!s'ault: .'>L'a!'! sy sLc!)): f.o). (I Univ, )'(!I . ( «ol . Sc i ., v, I.l, L) 9'! p. ~ HcCull ()(:h, D. Cl. II ~ .) I'i I )'.. <'c()L':, > r ( )',, S., ., 1(I, I. > I)., I I r, and ULLer, P. H., 1977, A summary report nn t: he regional geology, petroleu:n poLcnt:ill, ancl environmental pcology in Lhe area of proposecl lea e sale 53-h cenLral nd norLhern California ouLer conLinent:al shelf part. A, 39 p. Silver, E. A,, 197~i., St:ruct:ural inLerpret:aLion from free-air gravity on t: he California conLine»Lal margin, 35" t:o 40 H: Geol. Soc. A.nerica ebs, sriLh pro< rams, v. 6, no. 3, p. 253. Heber, G. E. > ance Lajnie, I:. R., 1977, La't;e PlcisLoceno and Holocene L'eCLonios of Lhe Sa» Grcgnrio faulL zone beL~~een Hoss Beach anno ltuevo San ttaLeo Count:y Cali- fornia: Geol, Soc. ho~crica Ab."... ~" iLh progra.",>s, v . 9, no. ~~, p. 52~i, ti'oodson, H, B., XTT., 1973, A boLto.n gravit:y survey oC t:he conLincnLal .:helf betsseen Poi.nt-. Lobos and Point Sur, California: Tttesis, naval PosLQl. a.)uaLC School, l12 p. l I lf 4, F' 1'.Q v I. e Ca p t 3.0 n s Figure l. Hap o2'entral California coast sho~"i.n;, geo~~rap!iic location an~1 fault citecI in te>;t and location ok I'I.pure 2. Figure 2, 1)etailed aeromapneti c map oC central CaliCornia co 1st bet; een Point Sur an(1 San Si.iieo s ~ Fl.iplit lines llQCl l mile spacing, Cloison normal l o 1:l>e coast, l T L l25 l22 l2I l20 '0 ~e Son- Fro no i.,"..i):.><'~'h~ Mont ere'i".i".~ ~Q) Pt. Sur 4:".. o "'r Cape Son t iortin"".:.<, San Simeon:i-:.':".;; "A-:yi'~ Figure 2 :Santa .f';maria :f3o" it> ~ ..-', l ra never.,(. Pt. Rrguollo '::...... Bongo., santa::.. l3arl>oia„::,, ~ 3i ~ vn'6 O. L ihorth Q ~ +~.s' '' . go ~ r 'i .%, ~( v tl / ~r 0 iQ 30 / isa Sonloit Intetvcl 50 nT I -Z reins -2'30 nT P I UllJTf'.D STATEO DEPAltTllL'ttT Oi'llE IHTERIOR GEOLOGI CAL SURI/EY REGRESSIOlt AtlALYSIS OF EAt!TttQUAt;E tQGltlTUDE Ail0 SURFACE FAULT LEttGTlt USIf'6 1'llE 1970 DATA OF BOt'ILLA AttD BUCttAl'A't By t!. t<. hark IInd ll. 6. teni'ala Pl et)ared in coo))CI cI t;ion YJi t 1 U. S, ttucl('ar Regula'I'oI'y Co:-uission.r OPEil FILl:. REPORT 77-Gld Ttlis l(IpoI.t is t)I e1iIIIiIIary «n(I .II t'tcnl o t'al't: C«l i foI'nial 1977 ~ )L I l ' I AEGPESSIO l AlNLYSIS Ol'ARTllgURilE fWGilITUOE All0 SURFACE FAULT LEWGTll UslrlG rllE 197O DATA OF BOllrLLA Alln BucllR',R l By P.. l;. l1nvl: and H. G. Bonilla Introduction. 1'he repo).t of Bonilla a))d Bucl) gressions of faul t length oI) ea)-thqual:e II)ag)iitude that can be used tn estimate most pl obable 1engtl) of surface )'upture given earthqual;e Ii)agni- tude. 1'hos(.'egt vssions, 7)G"Ievel", i)ave soi'Ictimes been incol')'ect'y used to estimat magnitude from'fault lengtl), as po)nted out by hal" (1977). Using th data of Bonill«a))d Buchanan, tl)is v(.po) t gives vegressior)s of eavti)(lual:e magnitude on length of surface vuptuv» that can be.col')'ec ly 1'u used to estimate most probable'agnitude if the leng h of su) face i,n'"'s given. It also gives the reg)'essions of len(ltl) of ) upture on I;:ag;)itu(l; tl)at cji) be used to estimate I,",ost pvobable length of rupture given ca) th- qua I;e Ill I gn) tud e. In table 1 and figI)ves 1-5 the nu~)beI"ing «nd 'lettering systea l sed to (l(.signate f«I)it geogvapl)y and )aul t typ(.s is the same as in Bonilla and Buch.nan (1970). l,umhers 1-09 include su) )ace Iu)t.II.es that occu).).rd in l'lo)'tll AIrierica «nd nun!b vs .")0-160 incl)Ide )'upiul es outside of'ool'tl) Amevica. The fa(I1 t types are iI)dic«ted by let ters «s olio;(s: A, I)o) mal- slip faults; B, reverse-slip f Iul ts; C, novmal ol)liqIIO-slip faults; D, reverse oblique-slip f«ul ts; «nd E, stvil;e-slil) f«ul ts. Use of'he ) rqI ession liI)rs. 'I'he )'rg)es.ion of log lol)gth on IIl«gni Rude. ~ ~ (Log L"-a Ibh) ca» be used to estimate the most probable rupture length given magnitude, and the regression of magnitude on log length (f<=a Loq L) can be used to estimate the most probable magnitude given rupture length. The estim Peferences cited Boni lla, H. G., and Buchanan, J. H., 1970, 1nte~ im report on wol ld wide historic su~ face faulting: U.S. Geol. Survey open-file rept., 3Z p. Harl:, I'.. )l., 1977, / magnitude versus fault length in estimating ma,",imum expectable V. S p, ~r('-- >r(=& Auow'/.. earthquakes: Geology,- ll ~ ~ ~, Table 1 ftegression analysis ol magnitude - surf'ace ruptui e lellgtll data froiii Bonilla and Ducli Log(L).-a+b~H i!=a < b~ 1-49 20 0. 372 10. 64 -0. 91 0. 35 0. 51 5.23 1.08 0.'. 50-140 33 0.217 8.57 -1.49 0.40 - 0.55 656 05 1-140 53 0.257 17.62 -0.96 0.34 0.53 6.03 0.76 0 14 0.175 2.55 -0.69 0.28 0 6.19 0.63 7 0.003 0..01 not s'igni I'icant 7 0.459 4.24 -2.01 0.61 0.38 6.08 0.75 5 0.006 0.02 iiot significant r 20 0.4i8'i 16.87 -1. 08 0. 39 0.52 4.96 1.24 O.r Zl 0.Z?9 7.37 -1.46 0.40 0. 4i5 6.13 0.70 0.'; 12 0.033 0. 34 not significant C!O?E 32 0.367 17. 4i2 -1.24 0.40 Oe5o 5.62 0. 93 (?. l: 12 0.230 2.99 -2.79 0 ~ ".9 0. 5? 6.62 0.39 0.': 27 0 299 10 65 -0.7l 0.32 0.56 5.71 0.94< 0 (', A< C+E 41 0. 380 23. 9'4 -1.20 0.39 5.56 0.99 0. 7:. 32 0. 251 10,07 -0.81 0.32 0.60 5.98 0.78 0 ('- ttotes "n" is tlie ilui "r." tiie fract,ion of tiic variance czpl II f is a ii!easiire o!'t II II s t,lie stln(!ai d eri or of tlie estiniat.e. s. 'is equll to t.li!'esidull .;in,> of evi'ol s '.l 000 700 600 500 woo 300 . ?00 IOO 90 00 70 GO 50 nn 30 '0. to 9 7 G 5 7 7. ~, l g Opl a 0(<0 700 GOO 500 noo 500 200 C') ( i-LJ IOO 0 90 00 TO GO 'D sn ( 40 50 t 'D I- C 20 LJ O A (0 0L I f> LJ r l" ' y00 GOO ~00 400 300 200 Ul I-bl 4J l00 0 '90 80 I- TO GO GOi 40 t K CL D ?0 Ld O In 0tv IO Z o y Gi O f17 '(0 0 + 0) 'tO C' 0 rr l,' l Oi00 700 GOO 500 400 500 200 C') iHORkifil. OBLIQUE-SLIP FAULT DATA I-LsJ IJ IOO 90 on 70 D 60 I' 50 C 40 Ll 30 I Q. 20 IO 9 0 7 6 Cn lQ h 0 Co D ~ a ODD 1DO GOO 500 300 200 (0 K Ld IOO 0 90 00 '70 I- GO cf 50 c' 30 Q: I-D Q. D ?0 LV C3 D CO ( In 0 9 x 0 7 4J I , ~ ATT>(t>CII'lL!IlT Bt>< 10 H+ ~ «> «I'a U11IL('.(1 i >t IIL('S 0('t)iII Llll(.'IIL ()f Ll)(.'(lL(.'I'IOI (< I'.Ol.o( l(h'I'>')u»vur I'e(I(r:il (,'(i:t.er 13{'l>v(if', ( (>I{>ct>(I(> It(>') Box 250'>6, Stop 966 April 13, 1976 1)r. E3.i A. Silver Division of I'atur. >1 Sc enccs >t'>ppli(.d Sci.c»ccs ilui.ldi:>I; Universi.(:y of CQ3 'ox»i,a, Sant.'a Cru" S:tnt;a Grus, C "liiv rni,a 9506~> Dear. Eli: Your 3.cttc.r of !'QI)ru(>ry 27, 1978, indicate your cont;i»ucd inteL'Qst in the cv;il(>ation cf: c ~ rth cience clata end intc.> prctatio > of it that way bear upoi> t:tie, a'.e opcir i>hen vc fir"t Leccived ) oil>. letter, ("e coi>sidcrcd resp("i> > I 3 .<'i> '\ 1."t 7 5 > 0 8 ea L I qu I(c s lion d l)e 1:hQ 0 c(>3 1 ( dc'. e l> n I>ll(''t'.hu>: >!<( il>'(' ~ ',>'>'>nl'ol'l':>i'>l, (".:<»> I < I>!> i'! {",>1(il 1'>' L(;(! < r <)rn . A» 'l ~ ~ a imporr.;in<: to Lhc ))iab3.0 Ca!lyon site i.'he ground lroL'ion to bu cip(.ct<:d At or very clo::<: (~10 lan) 1.0 the source (v(:pturin", fault) OE An carth- qua'<.e. As you probably kno(", no measur(.ments of gl nuntt ';>ave ever been made uithin 3.0 1:m oE t: he source of:1 3arge carthqu;l(c. <(s you a).so probab3.y ):no.~, );i.<;h Accclerat:i:ons )lave bhich Are hi.oiler t:h;lll,"'ny consider.ed Eov the ))iab3.0 si.te did not cause stvucL'uva). damage. Critical factor.'ov ctlgineuritlg design ar(: ho» 1"..»Ch and in»hat form L' L'hc Qncr',y is ll '":.i Le(. L'0 t)tc't(l ~ n(l i:1L0 the et> "rgy transmitted i!it:0 the Ear.'3.iaty iS 3.imit<:d by the u3.l:inlet:(.'treet th «lid trans:»is:: ibi).ity ch<(r<(c ter ist:ics of the voc!:s. Also it; is p'ostu)«ted that. th» ™cchoni::ms of: Era>et:ur1(> Callvon .",.':n, «v."rn;) th.:sc 3.it«its, they rt(:st!;!Qcordinp|y l>e sub'<" tell t 0 ~<>ecif ic(l rc To rep«.a>,t a st tcl('nt made At L'!lc bcglnnillg of th' 3.ct t('", (la! al.e conccl.lied over (1 t'1 L)',a 'a'ly hc ve3.eva 1 'o thc s'lfc opc L'i.oil 0 an" nuc3,«ar r<.actor.. As imnli.c l!het'h(,r ov not, or. )10 J soon, cstil,.ates of: 1:is!( (li.l.l b<'. incorporat:ed form»3.3y i»to vcvic»s of. m;1 jnr Eaci3.iti(:0 or activit:ics i ~ not: (lithitt ~ L'1!a'la. Oua. Put Vie!l l(ov:<:V<.'r > (/Q 00 'Nntlt LO (:a!:Phn 'l<'C t'n» a(1(a.! <:vo«p Eorm«3.ly pr(.sc'nt:lj»QX3.- !3es t' )' A ~ ) a<')>(!0(:(1 0 UNITLeD STATCS NUCLERR REGUI A I ORY COViMISSION ADVISORY COMMITTFC ON RCACTOH SAI'EGUARDS WASHlr'JGTON, D. C. 20555 June 7, 1978 C, P. Siess DIABLO CAt Attached for yorrr revieiv is a copy of a report lry our consultant, ter. T. II. Picl;el, regarding the seismic reevaluation of'iablo Canyon. Cooies of this report are being provided to tlr. other members of the ACRS and the I!RC Staff'or their inf'ormatior. ~ J. C. ttct'iirley, Chl.ref X Pro jerl: Revie>! Bref!ch iio. 1 Attachment: T.'ll. Piet;el comments dated 5/31/78 cc: ACPS tlembers R. F. Fraley, ACRS H. W. l. i ba rl:i n, ACR S E. G. Case, ERR (P-420) R. Boyd, DDPtl (Plr il -278) J. Stolz, Ll!R-1 (Phil-144) D. Allison, LI!R-1 (Phil-144) L. Crocker, DDPI! (Plril -278) J, P. KIright, DSS (P-9328) I UNIOfl CRI)BIDE COItPOBRl IOIR ~ ~ F" < ~ ~ L 'br I ~ IIUCLE/if! DIVISIOII P.O. OOX X, QA>: nlr>GC, TEl>>>CSSCC 37030 r> I' ~ ~ iaJ, gr I'lay 31, 19/0 ~ ~ > I i P \ >< ~ Ihr, lohn C. I~cf;iiiley, Chiet Project Review Di«nch Ilo. 1 US Nuclear Pegul«tr»y Commission Advisoi y Com;ii ttce on Reactor Sa fcgiia rds Vashington, DC 20555 Dear John: Ci'itcria irnpler>ientatiori Review Ilcetings for Diablo Callyoi'i f{ucleal Plant> tlrllt:s 1 all!I 2 During t!i!> periocl J<,nu<".ry 1G to February 2, lg70, .:iitevia implcr>i ntaiin;i vevicir nicetings vere iield witli I'G." 0»e session of tlic meeting witli f>GGE was devoted to t;lic iiitcvf'aces bet.w<.cn structiii'al co»sider atio»s arid piping, meclia»ical, ard electrical systcins I ~ Hr. Jolln C. lie!',inlcy hay 31, 1970 considerations, This session, which was attelid d by both stl.uctural engineer.ing personnel c~»cl nrecllanlcal enginceri»g pcvso»nrl, lras Useful in assuring Liiat a consisrcnt appi'oach has been Useo in tlie seisniic evaluation an Tlic seismic input for evaluating pii i»g, rnec!ianic«l, and electrical sys- ter'iis I.as discussed «t: solne lengtli. Th< Ir Tile pVOCe(!ulC-.- uS'.C! in Colnbiilirig In 1, li I llr. Joiln C, Hcf!inley Y!ay 31, 1970 discussed. A seismic anchor «rover"..nt stu The inte~ f The corr!bi»«Linn of I.OCA and sclsrrlic loads fol l>ranch lines in niping systerls \"as I QY1(ll'Q Seismic qual ific(ati<)n tests fov valv.s have indicated LhaL a fe'lv Y(llYes h Seisr«ic tests on so!I!Q vessels have indicated the prese!Ice of shell r I ) Hr. John C. l'icVinley tiay 31, 1970 In sugary, I thi»f; th» revie" meetings in.i e beneficial. Al tho«gh additio»al infnr;..atio» iias requested for some nf th.. items disc«ssed, I believe the conse»s«'(as that the meetin()s vesul ted in an i»cl ease ln confidence i» the seismic e.al«ation of the l)iablo Caiiyo» pla»t. It appears that the additional information requested can i)e supplied and the staff evaluation completed without e>:cessive trouble or delay. Sincerely, T. H. PicLel ll(P/him cc: C ~ P. Sicss 4 Lyg B!gg 0 UNITED STATES I~IJCLE/Lft REGULATOBY COMI'AISSION ADVISOI!Y COitt«>IITTEE ON REACTOR S'.! EGUAsaDS VSASkllNG1'ON, O. C. 20555 ++*++ June 8, 1970 Project:: Diablo Canyon Site U!!its 1 and 2 S ta tLls: Generating ?license Revie v Subcommittee I'!eet j.!!g June 14 15 g 1970 PackgroLlnd: Octot r 1973 — FS,'P su! ditto.i Sep tetmbe r 1 2, 19 7 ll — ACILS 0ubcommi tte meet in.I Octo)x;r 16, 197~) — alit S:!fety I:",valuation Ro:.or t (St I',) i ssued January 31, 1975 — Surale.'..=!it I".o. 1 to SF:R is The Diablo Canyon Units are e"sentially identical i; stinghouse foL!r leep Pt R J L yth core thermal p)wer ratLnq.'f 333(I ii><(t) anri 3411 Iu'i(t) . 'l>!" plant in located o;i a 750 acro. sit adjacent to the Iacific C"c an in San Luis Gbi 2o County, Califor»i,a, about mid! ay b twe n lns Angeles an.i Sar! Francisco. The ACRS revi ew=-.l the application for. a» o„:"rating license in June 1975 and wrote a report covering all aspects of th pro osod o&Lratlon e 'ce!,'t th" sei "mic design bases thte adcqL!ac! of the s ism,ig dcs ign, prot:cct.ion against tsunatmis, protection again t tornado mi"silo..-, environ.:"nt;n.I oualification of certain electrical caL!ip::.Ont, 'ater ha..„;"r effects, "L'b- compartmcnt analyses, systems int craction, pressL!re vessel supLiorr st rL!Ctu'~L'SI and gran< roc items rclatlng I 0 PIIIWS. )l t, Subseauently, anoth r ACiiS letter was transmitted on August 19, 1977 re- garding furth r resolution of nonseismic matters. The current revie~; address " only th s ismic issu s, Tne original d sign was for an SSE oC O.~g eCfectivc acc lcration. Gu!x;~~a«ent to the is uanc ~ oC Hie construction p=rmit, previous3y unknow fault (th i/os™ri fault) discovered offshor in 1971. I.'ollowing its discovery, the fault was sL«.i. extensively and in 1976 the Ceologica3. Survey concluded that th fault ~ias capable oC producing an earthquake oC magni;tude 7.5 on the!:ichter scale. The Staff s consultant, Dr. !".cd Althougn the Applicant does not agree arith the t!!lC SL'aff s evaluation CC the ."; verety of earth"ual;e possible from the Ilosgri fault, he t:;".s pro "ced .; with a reana3,ysis and strengthening of the plant based on the Hosgri event. The itCP~ (pd it" consultants have b=.n kept informed oC the eis"..ic design bases and the reanalysis program. The AC!'.5 and its consultants have 'not forma3.1y agreed that the seismic design bases are appropriate or t>nt the plant design is adec„.'uate. The purpose of this meeting is to atter".,;:t to leach a decision regs'rdlng the adequacy of th bases and the reanalysis- Corra'ents Crcm all of th !XCB"- consultants have boen provided to tn hRC Staff and th" Applicant. I ~ ji UNITED STATES NUCLEAR REGULATORY COMMISSION ADVISOAYCOMMITTEE ON REACTOR SAFEGUARDS WASHINGTON. D. C. 20555 June 12, 1978 E. G. Case, Office of Nuclear Reactor Regulation R. S. Boyd, Div. of Project tlanagement R. J. tlattson, Div. of'ystems .Safety ff, Denton, Div. of Site Safety If Env. Analysis TRAtiSflITTAL OF 'lfRITTEff STATFflEttT RECEIVED FROH THE PUBLIC BY THE ACRS The attaci'.ed written statement was submitted by John R. Bakalian, for the Diablo Canyon Subcommittee Heeting, June 14-15, 1978. This iteill is plovided for your information. ;)P / J. C. tlcV.inley„Chief Project Review Br'anch tlo. 1 Attachment: Public Statement by J.R.Bakalian dated June 8, 1970 cc: HRC Public Document Room J. A. Harris, OPA ACRS fiembers ACRS Consultants: J. Luco J. Haxwell T. Picl:el G. Thompson tl. i~hite B. Page tl. Irs f«nac ' fi NuCLEAR MORATOB UM TASK FORCE THE TIIUST BUILDING,THIRD FLOOR 105 SOQUEL AVENUE, SAN1A CRUZ, CA 95060 (408> 425-8355 June 8, 1978 Nr. John C. HcKinley Advisory Corrrrrrittee on Reactor Safeguards U.S. Nuclear Regulatory Commission l'I/li I!ashington, D.C. 20555 : n)I Dear People: Re: Subconmrittee lrearings- in I!ashington, D.C., June 14-15, 1978, on Diablo Canyon reactors, San Luis Obispo County, California A crucial question of public safety pursuant to oroposed operation of the referenced reactors was addressed during the Fall 1976 hearings of the California State Energy Commission at Avila Oeach, California, on evacuation plans required of the surrounding rrrunicipalities. You will find in this testimony the docurrrented opinions of several highly qualified scientists regarding the potential for disaster which would follow an earthquake along the Hosgri Fault of a magnitude at or in excess of 7 ' Richter. Additionally, we would direct your attention to the August 1977 review by the Union of Concerned Scientists (UCS) of I!ASH-1400 (HUI Further, the UCS review examines PG&E's argument that because tire plant is nearly completed, the benefits of oper atirrg it outweigh the incurred costs. I!e submit that this argument is transparently specious, in view of PG&E's and AEC/NRC's histor„i of ignoring tire January 1971 published findings by Shell Oil geologists Hoskirrs and Griffiths. As you r'.ray be aware, their survey findings indicated a 100-rrrile fault (the Hosgr i) along the Central Califor.rria coast which passes within three miles of the Diablo Canyon site. It is our position that the contirruing ref{tsal during 1973-75 by the NRC to grant a stop-work order orr the Diablo pr oject, as was re- quested by the inter.verrors, constitutes pr illla facie evidence of collrrsion between PG&E and the regulat:ory aqency to circumvent NEPA. I!e urge tire rrromber s of ACRS to reject the curr'ent atterrrpts by tire interested parties to furtlrer corrrprorrrise public safety for pr ivate gain. Sincerely, ..7 ) ,j'g J,~,..P,c.':g~r.'IC cc: The Haslr lngtoll Post; Jack Allder'son: UCS; Cerrter for l,aw/P{rhlic I»I'err'sr' J ~ h gnn "(0'( 0 UNITCO STRTf S NUCLEA!3 nE(3ULRTORY CONIC!ISSION RDVISOIlY COMMITTff OH nfRCTOR sRI'fGUAADS 'LVASHINGTON, D. C. ZOs55 «"*a" June 12, 1978 C. P ~ Siess DIABLO CAHYO!l COHSULTAHT'S REPORT Attached foI. your reviel. is a copy of a repol t bv our consultant, Dr. i!. D. Tri funac, regarding tile seismic lecvaluation o" Diablo Canyon. Copies of this I'eport are being plovided to the other melllbers of '!;he ACRS and the hRC Staff for their information. ./ ~r'J. C, !!cKinley, Chie"'- Project Revielv Bl.anch l!o. 1 Attachment: fl.D.Tri fulrac comments dated 6/8/7!3 cc: ACRS Hellber R. F. Fraley, ACRS I!. !!. Libarl:in, AORS E. I', Ca s e, I..RR ( i -<28) R. Boyd, DDPii (P)l'il-278) J. Sto! ~, L!m-1 (rhil-1 ' ' t>I4IL>l;PSI I'Y I'hltli I.OS hY(II:I.I'.S, (hi.il>i)I(VIA'/0<)( ~ ' < CIIOOI. ()I''.M.>I si I'.I'.I(IY() I <'"'>3 >/, I) .Phlt'I'I>II"..i"I')I'.'I'>'ll.I'~:(:IVI'.I'.I'IX<'G Junc 8, 397 ~ ~ ~ ~ tii'. J.(:. IICI'.in].cy ACIIS USIiitC it';isliiiil,t.on, II.C. 20!i."." l)ca:; hi'. lie);in)cy, 1 tlvil cnc)osi)'.<> v'.y cnl«itl:Itions fo)'(:Il, I;)'ound nccv)cr:tt'iol>;t t))c UillbJo C;>»yon Sitv in C;>]i fo)'>litt. Io s'Irc ti.itic ) cltosc 'L'0 d<. '3;0 t.lic 1'est>1 t s you 1c(IL>cstcd f)'ot I t'ltc cxi.st;3»~<„''cpol I; t'0 A(.liS by At>det's:;1 nnd 'I'r] I'L»1(lc (19<7) . (:Onscqttcnt.) y, t:Ii<3 I oi )!ni'i»p r(stilts n]so r(pr(: .Iit I l>v till>pli t »('vs of U» I )'orltt Ri s); 'AI>so liit c Accc) erotica Spec <': 0 ':". t,';:e rio0»s> ~ < ~ nt>I:L)3'il) )')C1'30d of s>,L I)g I 0-dc ) cc-0 f-I:1'ccdo>II sys tclil c(ILI(t] zo 0 'I s('c at><1 t(c cl>a >)oyc<. ]ii our !'rcviot:s I"ort; ( u'.dcrson T) i fun I'1!>Ll)'«s ) nnd 2 prose»6 t lie ni>tp]3 I:Lldcs oi: Un) fot'In lt>st( spcctrn nt: 'I', =- 0.0I scc. I'il!Lire 1 is I>:Ised on Abs01(tt('Iccelc)';It:.Iontltc:Isstt-.,t>- I:ion t.l>:)t. 0;trtl>(!u:It:cs c;»1 bc Itod«)cd by;i I'oi: so» s« Yotl )'c(I(I<)st«d tltc vsl:i>litt>:Qs oi; p("II; <>I'otlnd tlccvl cr;>tion tbnt: I'0>I I(l l>t)L>c I'l('. p'vol»lb) 13 I y of') t, ] <.';Is>~ 0»e chic(( d;I)tc('. c(I>>1 1 t'0 0. SO;Ind !or "0 t.ll('. I'litic I>',LtldoIC 0!> <)0 yctirs. I llc. c tice«l v)':It 3.0>ls «0)')'cspond t)l< pr(I);Ii ility ( F;tt 1«:Ist o)i«ex <'vd:tncv c iii:)) to 0.:( litri)is, 0:0 ti'i»do>i I'or t(bi«li ti>c (;>letil;Itioils;Irc )'(;tdi]> )L>:Ii);tblc. I'II)lcy<':it',i>ttv 111 't '> su>1>ill ~ 1)'3. a<«1 Il'(. 1 csu 3 I ~ ~ I I Jt ni)I)onr.", t li;it nio Collyoli 3 i t <. ~ Si»cci <'ly, ll. I). 'I'vj ri»i;ic I . S. I Bi!1 Cllc) on)»p I lio I'l)ilI k' Ml)i:p 3""i'u.: Ilo.'„'ri 's '":i I' = C 0 I io» 1'c ~'<:i" ( I. 2 Co:» (I~v:~ovio»» AS,'iz (Ir ~ 2) ) l< I] 'I'ii.LI L'! . !:j,ft;y Ycnc Sc) "-):ice).t,; c'sed I o)' .cl) ~~c")'<'c lfo J)) t.1:c .'~)):i)c vie;)]. (i:ilcu]'i): inn.", i~locI c]. 6 6', 7 ]?'9 ~) S 16 6 2 0.6 0.2 0,1 ]], r., D3fkusc po))c 'I.2<> i) S ]6 6 2 0.6 0 0 D, L'. 0 (I 0 0 0 0 0 0 0 0 0 0 0 0. i)S ~ 0 S~)} ti) 5)lc7 F'u) 1 t' 0 0 0 0 0 0 oi 0 O 0 n O 0 0 0.] t ~ ' ,j J ' t I'("tI: /cocclc r:t t:in t. i tt g'.: «'!t i c lt It't".c'.!tc I't' lil'tot'al l SQ(I tl('ttcu Sc i.'.:ni c t I ..'Ioclc! ) ll I iltlC .28 . 2<1 .a2 .Sl l 1 l ')' >., <3) i 1 ):J '3 I. 7 .. ( I ~ Q rl f'II r Ir I g 1 t 1c%) ~l j) e < Ip I I I I rir l' r ~ j J i;).,~"'' ', 'I L. )., , ri' r" 1 d ,C (f ,.( r) 6 r > J J .j ~ 25 ') VO J I -l .c.Oq I I tI.~ 'i g'lI ' I ()' I I I 6 r I I ~ I C1 I 0 J'l '<( i V: >-(' i~>0'OE l. ( ~g 0 L)<'.(~./4 <~ C. ( s l) f„...c,(. l P I ('l I 'L I .r p) 1 "g- I4I l \ ,0 ~ C'...;-" , ~ a l I, ag ~ ., Q V \ I ~ ~4 Cf C "05 l- I ,(b o F:; I ~ - 1 .)- s i(~ () Il I I ~ P N 0 X ,Oil'I'Ill. oj~' " ~++ UN>VCn.Sra v OF SoU>HL'i C. IOOI. OF I NGINRI'.luNG 0:-PAltTMI",NTOF CIVII I'.NGINI!'.RING April 21, 1978 hir. J. C. ltct:inlcy ACI Dear htr. htcl'inlcy, I am enclosing the draft: of Rty conuncnts on thc Diabl'o Canyon si.t:e. I i~'ill send t:)>c iinal vcrsio» as soon as possible. TI)e comlaents on I;hc SAht V procedure by, J. Blunle Ntlich werc Inailcd t:o you on I'cbruary 28, )978 can l>c considcrcd as fi na1 noii. Though some fine teclut i ca 1 points I here»ould call for a )vore dct:ai.led di.scussion, this is not: necessary for t:1>v present purpose and usc of tltis rcport. Si,noel4,n.;~cly hl. D. 'I'rifu»ac tlDT:gd Enclosure A li ~l ~ ~ COi~illENTS Oil SEISIIIC f)l!SI(iA I.I'.(if!I,S I'OI< DIAI)I.O CAHYOih SI'I'll I!i CAf,if'OIUilA I>y The followinl! co)tm)c»ts dcai witi) seismic dcsil;n crit:cria fox t:hc Diablo Canyo» site i» C;) li for»in;Lnd reprcsc»1.';1 bri cS su»)a)a)y o". my ol)s!.rvations a»d prelim(»:)ry conclusio»s which a)'c b:)scd o» )1)isccll;)ncous writ t:c» a);Ltc) i;Ll a»d n»;(»L)mbcr of meet.ings (!Uri»g the pcr'iod sta) ti»g i» tl)c sua)mcr of 1977 an(l c»di»l! i)1 Apri! oC ]978. I»for)a:Ltio» 1'hich I had o» ('crt;ai» aspects oF this effort ma)'c )»compi<'t:c. Thc gc»crtl'1 })icL'U)'c ".»d t'llc st!Ill!11»ries of t:hc cur)'c»t status of: this project »evcrthelcss seem adequate for ihc fo1 l owi »p co))m1c» ts and rcco)1m)cnda 1: ic»s . h!L)cl) l.;)s bc» w)'i):tc» abot)t dctai lcd aspects oF seismic Gc»(')'al CoIn)))c»ts 0» t.hc CU)'1'(.'»1; Il~l)uts 1»d Cri tel'J 1 For Sc) s)"ic Dcs11,'n ~ G llosg) ). f;)L)lt. opposite tl)('. l)l;)»t. site sho))ld bc a» ll = 7.5 carth- q)):)kc. Thi.s )Allg»3 t:udc, )'cco)mlle»dcd b>'lSGS, has hcc» dclcrmt»c(l mainly on tl)c basis oE tl)c possible ic»gtl) of f:)ult:inp on thc l los l!r) Fa t) 1 t; si)'s t clll. 2. Si»cc hl:: ".." at a list.;1»cc of S - 10 lia) C)'o») thc siL'c lead t'o ]:))'l!c pc))k, accc]('.):)tin» (:)l)o()t l }',) co»side)"1)blc cl lort has bc('» d(.vote I t() thc;1»:) l>"c''h)ch il)'( d( slli»(d t(~ ',ho i'll)lt. I )4 these I Ir)!c ampli.tudes can a»d m;)y bc rcduccd thro«)!h considera- tion of t))e fol)ol4).ng phe»QIIIC»a: a) Scattering a»d diffr:)ction oF high f)equ(ncy w;Ives from thc foundatic»s OC different plane strllcturcs h as a vehicle to justify eccl«et)o» oi'i),h f)'eq«e»cy sp has b()e» affected requires u»rc;)list) c )ssu)I)ptions, fol cx- amp) c, th) t fo«»datio» is )'))!i<1. '1'hc II)anne),i»»'hicl) this assumption is i»tro and co).side) s mai»3>'»1> those co»sc<)1)cnccs of thc physical phe»c)IIC»a»hi,ch )cad to reduction of spcctr;Il:amplitudes. Othe) co;)scquenccs OE this phenomenon, for cxa)aplc', torsio) a) and rocki»g czcitatio»s of foU»d ttlo» '»'hlch )Illy:»Iiplifythc st)'I)ct:Ir;)1 response have been, so f )r, either ovcrlookcd o" trcatcd i:)a of d>'»'»I)ic II)odc1 s for ana) ysis»hich are so defined that on1y 8» ) nco)I)p1 etc ph>'si c~ of th .. prob 1 em, i . c., sci s)a ic cxci ta- tio» I«I tha»;)et«;Il pe:Ik;Iccelcr;Itjo». Thou).h such I)p) ) oach may bc us('ful 5 ol'il1'Ihq« lkc ) ('s) steat t) ve ')cak:)cc('.1CI':It) 0»" h)ls»ot bc<'» dc Fl»('d i» II '4'a>'h:It wo«)d c»;Il) le t)IC «Ieriv;Itio» OC co»sistc»t rcs))l ts by seve):)1 ~ ] 3 diffci'«nt expert.s in thc Ei.eld. Si»cc thc proccdiircs for. scali»g Rcguli! t.oi'y Guide 1.60 spectr;I arc based on "i'Iaxi!III(ra vibrat.ory groiind;iccelcr;itio»" (as defi»c this departure Crom rout.i»c dcsig» pr;icticcs makes it di Cfi- cult: to evaluate thc»umber a» IIhich I(ou) d resu 1 t from s«cli in approach. c) flypoccn'ral r It'.hcr thai> This assumpt:ion iiap) i.cs cert Nave ciicrgy. Thcsc ang)cs oC appi.oac)i slioiild then bc con- siste»t Iv'ith thc extc»t 'to hhi(.h "T «Cf(.ct" is al)o».cd to influci:cc the spcct.ral ar,:plitud(s. Lit.t)e or»o att,c»"ion seems to have bec» give» to input,ua) ro»sist«»c> of:;;hcsc assuiiptin»s:Ind in sonic ci!s«s, inco»sistc»t: assumpt:io'IIs have bccli ut: L)3 7cd. l'0)'x the dist'ance at, (which pea);;Icce)«r ition is cvaluat«<, thiis redu«i.»g thc cst)III;It;c of peak acc(.lciatio» amplitu Ii'ovid, however, also impl> that t.lic I;;Ives arrive toi:ards thc fo(I»dat:io» almost: vert:ical i>. In consi how('.v(:r, hori=o»t:I) (lim«nsio»s o fo(I»dat.io»s appc;ir "o have been iiscd !mplyiiig horatio»t;I) i»cad«nc(. OC I'aves. d) Tlic ):Iigc d;Impi»g c cxc i t il t: I oil Iilll>'c IIILI«ll ):ll'g(!)'".)I'Ili7'v, 'I lit(dc(lii(it (, li(isi s hiis t', >' I I". l! l s>'st;cliis bc('li p1'( sc»t:('d t'0 ) (is i f u d(lltlp 1 'Iig Il s rile t (II I ~ 1 only. Sclcction of too large structural damping coiiplcd with o>>ly >wo-dime»sion;il or simp1e tlircc- of soi l-str>)ctu).c interaction can 1cad to unrcliablc rcsponsc estimates. 3. At least tlir(e seismic risl; studies li;i.c been prep;>re.n cstiiaa(c thc p)'obabi lity of excce l>iablo Ca»yo» site {Illiinic, Ang;iiid llcwIlla>I: Ail 1'hcsc studies h)ivc prod(Iced rcsu1ts > liicli, i» soac cases, diffc> by as iricl> as ti'0 ol'dc)'s of >i>agni.tude. Concurrent I ith thc corn>- parisons o~"; tlicsc studies, considcrablc effort h;is bccn (!cvoted ,to di ffc>'(:nt dctai,1s in thc p>ctl>odology employed in these calcul;i- tio»s. little or»o explicit effort;>nd ('isciission has bccn de- voted to tlic Ii>odeis of scis»>i ci ty which Iirc cssc >tia1 input i»to si)cli calculatioi>s, cvci> though tl>i s may reprcsciit thc Il>ost ir>por- tant col> t >') bi> tioli to tile disc>.'cp Jnc les iil!Ioiig t lic >'csul t s 0 f di ff()'cnt stiidi<.s. I» some extrem ci>scs (c.g., report by Dl(nac i>lid K).)'el>>ld) lal>) cliibo)'i>Lc worli h(is bee)i c:irr) «(I oiit, i>ppill'el>tly ii> vain, to sliow tl>;It a p;irticiil;>r, mct.liod for sc ili)ig pc:Il':>cccl- cration ('I')'if»»;>c, 1()76) supposedly 1ra of p(L(lk ilcce10>'Ii't > oil Lr>'cigi>I'd I css of tile fiict tliiit Lliosc ) cslll ts of 1'rifu»:Ic (1!)76) li;lve never been >ised ln(l do no>. )'(present a basis for >lie «Icriv:itio» ol'., scisaiic risk mo(leis by Aiidcrso>i a»d T) ifiiii:ic. 1» thc ) cport 1» A»I! I»id tie»I!!»>l;, sul)st smal1ci thai»:v(')';>I'.( Sci smici >y h;is l)c«ii assn)!Ied )>c;ir >lie site. 1'h.is I!Iay le:Id to:»> uiide> cstiai:itc of actu;il ri.sk. .1 ~ I 1 ) Icc omni en() a t i0» 5 A. Gl'OUI1d llot:ion: l. 1)ctcrmi>iistic>:>pproach based on thc assun>ption that an earth()uakc of'I;)gait«clc ll = 7.5 or g>eat(>r Mi)1 occur oppo- site the pla»t sit.c sho«ld he rc-evaluated. 'I'hi.s n>ag;>il.«de might bc an indicator of thc cz>ent of ),colo);ic f;>«itin), phenomena L«t it is»ot necessarily the most rrliabic basis for cva)«:cti»),the»at«rc of atro»g sh;)ki»g close to thc fault.. 'I'here are nun>crous cx(>n>plcs i.:> literat>>rc of si>- nixie I»t di ffCrCnCCS bet.(een i~) a»cl i~l, 01 CXanl))IC ''>ieh arc base(I on short;I»d ion); periocl sei sn>ic I(arcs, rcspcctively. Often studi.cs have sho>'» that 1») ge> earthquakes )>ay bc tho>I),ht of;Is:I sc(I>>c»cc nf several or many c!iscret.c cvc»ts >(hich ca» sc()u('»ti:Illy t:Ikc place (Ilo»g a lo»« fault. )"i»ally, thc lar),est recordrcl acceleration, so far, has rcsultcd for W<-6.5 onl>. I:or these rcaso»s,;Inc) from thc clcsi),» vie»- poi»t, J Ivo«)ci prefer to adopt l)=6.5 on )los)',>'i opposite thc s J. tc («>d»ot )i) = 7. 5 . 2. Hc;Ir-fielcl sou) cc theo» (I>ot a fi»i>.c clcn>e»t o') finite ~ di ffc)'.(.'»('.c Inodcl of thc sol>rcc i>»d ) t. s«r>'o>II'I(li»I,S) co«1d bc «sccl i» co»j>»>etio» ziti> tl>c spectral a»:>lysis of: st.ron), )notions rcco)'dcd e)scwhcre to ev:>lu:>tc thc: an>pli Luc)cs o resp«»sc spec'>'a )»dope»(le»t of pc:lk:>eccl c»" t >()» est.) n>;It.cs or of scis>nie ri))k;»>;Ilyses. I 1 a II. ~Iles >oiisc: 1 . Tlircc-dimension;i l so i1-s true t bc corri cd ou t . Th i s sliou l field ) cspoiisc sp et ra for desi gn rcsu 1 t I'rom inc i.dent SII, S4'r It;iy]c) gh Li'aves . For SII an'si s s!)oui d bc co)is i dcrcd . 'I'h) s approac!i L>ould of I'cr thc EOI 1 owi »I, a a . 'I'lic "7 t." e f fee i. f pres«»t will bc ti«co(i» t,cd fo) correct I y . b . Toi'siona 1 a»d roc!(inp exci tat iona L'1 1 1 bc inc i(i t!ic ana]ysi s correct)> c. T!i<; prox im it y of t he ca rt h t!ic waves )Lost 1 iI:ely:i)'i i vc hori tont;)1 I y wi 1 1 bc acco(:nt( (! for correct I y. d . Tlic i;)diat:io:i dampi nl, iii t lic so 1 i'i 1 1 oc in t;! oduccd i»to a»a1ys is pro»cr1 y so t!ia t the hi gh va luc of 7".~ or struc- tiirts wo() 1 I!xc('.pt f'r t. hc fact t'Ii:it 7". d:iml>i»I is pci'm) .".: I hi( acco)'d) nit to t!Lo )'«g() l:Lt,l i'LI', vli I (Ic I . 6 ) th \ s IllL',ll st)'(Let Ll I':L I dilliipi )if', i'('.«oiim)c tided t o i' li«sc is)ni (i:Ln;LI ys i s:L t t Iic l)i:il)I o (::»)> o» s I I c Ii;is i)ot h( «n j L)s t i- I Lcd. I'creed vihi';it.ioii to.',t (:)v;) I I:il>1e )» l!.S.;ii) Lw'hCVC l!I(' I I «C i. OI SO I I - S I i'l(' Lli'('- 1)i t «r J C ~Cq P0 UMI I EO STATES NUCLEAR REGULA I ORY COMMISSION novIsoI~v coMIvIITTEI!oN nrncTon sAI'EGunnos June 9, 1978 C. P. Siess DIABLO CAIIYOII CONSULTANT'S REPOPT Attached or your review is a copy of a rdport by our consultant, Dr. J. Enrique Luco, regarding the seismic reevaluation of Diablo Canyon. Iopies o; this r poI.t are being provided to the other rrembers of the ACRS and th.. l!RC Staff for their iIiformation. ,ry ./ ~ ..O3-C.'icl'inl ey, Chi e~ Project Review Branch Iio. \ Attachment: J.E.Luco comments dated 6/S/70 cc: ACPS iiemhers (Attmt. mailed under sepaIate cover ) R. F. Fraley, ACPS tl, !i. Liharl:in, ACRS E. G. Case, IMARI! (P-428) R. Boyd, DDP!l (I'hil-270) J, Stol z, Ll!R-1 (PIIil-144) D. Allison, LltR-1 (Phil-144) . L, Crocl;er, DDPIi { PIIi1 -270) J. P. Vnight, DSS (I'9328) 1 1 i Ul'tlVl',IiSI1Y Oi'AL,II'OilYIA. Sruti"J DII'.Go tCAIILI'Y chYI1 IIIVINII 505 h::(:I I 555 IIIIIII~IIIC 5hh DIIrII 5%V I IIANCI~CO IANYA IIAII>'AAA sjgC.w ~PJ '%V'EPAitTMEIIT OF Al'PLIED MI.CllhNICS hND ENGINE El'.LNO CICIICES, I lhll. CODE 0 050 Lh JOLLh. CALlfORNIA 92093. PJtPI 5. lg7 S art LIVED ho.qsn;'r sc.'-nrrY "" r ELEC'lcd Sht LL'I'Ers i Mr. J ~ C. Mci(inlcy ChicE, Project P.cvi«v; franc)i ~«o. l U.S. Nuclear Rrgulatory Colnmission Advisory Committee on Reactor Safcpuards IVashington, D. C ~ 20555 Dear Jo'hn: Enclosed i>lease E';nd my comments regarding Diablo Canyon seismic evaluation. Sinccrcly yours, C.- -~/--=" J. Enriquc Luco / JEL':bs Enc. )l l a H I I REVIEV, OE TllE SEIS;lIC EV.iLuiu"ION EOR POSTULATED 7. Shl 110SCRI EART!1QUAKE, UHITS l AND 2 DIABLO CANYON SITE'y J. Enriquc Luco A Rcport to thc Advisory Committcc on Reactor SafcLuards U. S. 1 30 hfay 1978 ~ j ci I ~ I i ~ ~ ~ '}EYIE}'tA}PD RECOhfl}Eh}}}ATIOWS After detailed review of thc rcport 'Seismic Evaluat:ion Postulated 7.5hf llosgri Earthquake'Rcf. 1), I have thc follow}! comments and rcconnncndations 1. proc-pic]d i)onion Scccrrom. In my opinion, chc ircn- field design spectrum used for rc-evaluation of thc Diablo Ca»y, Nuclear Pot:cr Plant docs not reflect the st:rong !notion a'hc .".:- for a 7.5 magnitude. earthquake at'n cpiccntral distance of 5 kilometers, but rather thc r!otion for a 6.5hf earthquake at t;hat di"ta»co. The free-field design spectrum developed by ivcthma!k and adopted by NRC corresponds to a simplified vcrsio» of thc average of thc t1 o Pacoima Dam spectra recorded duririg th.. 6.5." San Fernando earthquake tiith thc high-frequency portion reduced by uso of an 'eficctive'ea}: accelerat.'ion (Fig. 1). Thc }Blu!.". desig» spectrum developed for the applica»t closely follows t}!e Netimar}: spectrum. The peak- acceleration, velocity and d'sp}.ac'.- / mc»t co»trolling the high, intcrmcdiate a»d low frcqucncy port.i of t}!e }}esmark design spectrum are in agrccmc»t 1;ith thc aver;1;.: (50h perccntilc) peak valdcs obtained by Trifunac (Rcf. 2) ior 6.5}f earthquake !i'hilc falling short by 40 to 60 percent fro>m t}!i corrospo»di»g values for a 7.5hf cart:hqi!a};c (Table 1). Thc peak values co»."istont 1 it}1 the }fc1:inalk spcct:I'ur!;lie also co»sidcrab'o1 cr t'ha» those suggcstcd in US(iS circ;!lar 672 (Rci. 3) as s}!oi in Table 1. In adt}itio», comparison of thc i}cl'nllr} and Blutnc d sig» spcctr;1 'Li'ith cs tin!;lt.cs oi'hc aver'1gc I'csponsc spcctI'un1 1 o: t J 7.5)) cart)iquakc as obtained by Trifunac (Rcf. 4) also shoi's differences oC thc order of 30 to 50 pcrccnt (Fig. 2). The applicant has indicated that thc thrust fault mechanist; and the location oC thc Pacoima Dami instrument in the San Fernando cart)aqua):c may have incrcascd thc rccordcd peak accc'- eration. Thcsc possible effects arc negligible in vice oC t)>c fact th.t thc standard deviation for pea)r accelerations 4')lic)> has not bccn considered, corresponds to a iactor oi Z. Also, t!, records ior thc i~)s-7.2Gazli, Prussia carthqual;c of 1-7G i»dilate peak horizontal accclcration of O.Sg at an epicentral distance < 10 ):i3om«ters. Correcting for attenuation using thc Gutcnbcrg'. relation leads to a pca); acceleration of 1.0g at 5 kilomctcrs thc Gazli carthquakc in gcncral agrccmcnt iiith the results of Tritu»ac and the USGS rccom>micndation (Table 1). In vicki oi thcsc facts, I must conclude that the Nci~'suer); a: Blum design spectra do not correspond to thc groun'l motion Co: 7.rH earthquake at an epicentral distance of 5 kilomctcrs. 1 p: pose that t).c cstimatc of thc avcragc respo»sc spectrum ior .'l--7. 5 kilometers, epicentral distance and roc): sites 'oi Trifun,.c (i'; 4) bc used as design spectrum. This spectrum is consistent ii'it) th«only records availablc ior large m~agnitudc and short epicen- tral distances (San Fernando, Koyna and Gazli) as well as i'it)i VSGS circular 67? rccommcnda t icns . 2. 'LCC«ctivc'eak Acceleration. A judgmental factor )ic: bccn used to rcducc thc 1.15g peal; acceleration rccommc»dc<) in l)SGS circular G7" to a value oC 0.75g. This ill-dcCi»cd factor 2 ~ ~ , e ~ ~ ~ ~ has bcc» used in thc past to account for disc:cpancics on thc lc;el of damage obscrvcd as compared with thc predictions of ordinary seismic analyses which do not account for thc effects soil-structure interaction, are based on nominal values Eor dami ing and strength, assume li»car bchavi.our a»d do»ot iricludc th energy dissipation in partitions and other non-structural clc ments. This catch-all reduction factor has no place in thc de- sig» of carefully analyzed structures such as those in nucle»i power plants. Factors which may reduce thc rcsponsc or thc oi damage should bc identified a»d properly included\ in thc st: tural models. In the case of Diablo Can>on, many oE these fac'. have alread> bccn incorporated in thc analysis: use of te t strength rather than»ominal values, use oE higher tha» cot»ao» damping values, rc 3. On thc Fffeet of Scatterin<; of li'aves b Ri<,id Fo» scattcri»g of w»vcs by the supposedly rigid fou»dations . This correction amounts to a reductio» of thc Ncwmark Ercc-field dc.". spectrum by ?0 to 30 percc»t for frequc»eius higher than 2cps. Sligh tly lower reductions have bccn used i » thc Bi»me ' . pcc trw Thc correction for fo»»datio» scattering ci Cccts is based o» th 3. 4 I j I ~ 'ssumption oC. a rigid foundation and horizontally propagati»g Sl" i aves. Although thc assumptio» of a rigid Cou»dation ma;. bc rc. sonablc, it must bc recognized that deviations from thc a sumpt'ead to localized higher strcsscs in thc lower'portions of th<. different structures. Thc assumption of horizontally inci foundations s practically nonexistent give» the s) ecccntricit> of 5 percent core cspon [:ig. 56 o f Appendix D39A, but not used in thc analysis, sho« tha' peak torsional acceleration oC thc order of O.l rad/scc'orrc ponding to a peak tangential acceleration at thc base of thc co»- tainmcnt exterior of 0.2g»ould be more appropriate. It may bc concluded that thc use of a 5 pcrcc»t eccentricity underestimate; the torsional input by a factor of Cour. This obscrvatio» is co. sistcnt. «ith thc original «ori: of Nc«mark (Ref. 5) «hich indi ca< ~ that an eccentricity of thc order .of 25 pcrccnt «ould be »cccs.: to rcprcsent thc torsional. c Cfoct i nduced by hori "ontal1> pro p: gat.ing S)),«aves. It must bc mcntioncd that, thc increase i» pc»i'cceleration oX 0.2g based on a more realistic estimate of the torsional input mor than compensates for the reduction by tau- filteri»g from 0.75g to 0.67g for thc containmcnt: cxtcrior. I:rom thc point of vic«oC. the analysis of thc structural spo»se, it docs not, seem adequate to i»troducc thc torsio»a). in" / * through the use oC 'accidc»tal'ccc»tricitics. Such proc(our'I leads to the cnupli»g of t'hc torsional and translatio»a) .'hich sponsc in essentially symmetric str»ct'urcs distorts thc rcspcn and thc natural Crcqucncios oC the ystcm. Tl>c cficcts oC thc sional input may bc significant for thc t»rbinc building i» «hi the possibilit> of portio»s of thc structure undergoing i»el:)st" dcformations may i»crcasc the eccc»t,ricity, Xf it is sho«n t)iat thc seismic excitation at thc site cor rcspo»ds mai»ly to liorizontall> incidc»t «aves, thc rccluctio»s %lie tra»slatio»al a»<1 torsional rcsponsc should bc evaluated ou thc ba is oC thc morc exact methods prcsc»tly availablc. To 5. ~ q I 1 IC l ,I include an cxaggcratcd rccluction of the translational motio» ~:: out incorporating thc iull torsional cffccts is improper. 4. Soil-Structure Interaction. In Appendix D-LL3A of Ilci tltc applicant prcscnts a comparison of tltc results obtained by fixed base analysis of tltc axisymmctric containmc»t model ~'it!t filtered spectra as input (I:.D.Axis>'m.) t;it)t tho: c obtai»cd soil-structure interaction finite clcmcnt model vitlt the Nctima: free-field motion (<"ithout tau-f ltcring) used as surface co»t.: motion (PI.USII-SSI)., Based on tlte result:s shot'n i» Fig. 3A 1 c''. hppc»dix D-LLAMA, t)tc applicant concluded that 'thc use of t:au- filtered inputs vith fixed base models as used for seismic arai of Diablo Ca»yo» structures is ccnscrvativc.'his,,compari. on not valid, and the conclusion is not ti'arrantcd by thc ana» sis For a valid comparison, tic raust rcqui] that thc fixed base »~i ymmetric anal>sis and thc fixed base PLUS)I a»alysis give cs»:.::t thc same response cveryl:)let .. except ai )li g)1 frcquenclcs t:Ilcrc fixed base PIUSII results not.iifcluding t)tc tau-filtering shoul" sli.ghtly hi.gher. This is not: t)tc case as s)town in Fig. 3 of ti'cport: obtained from results shot;'n in Figs. 3A-1 a» by coml~ariso»s of the type s)io» in Fig.. 3A-l. I t: mu. 'btai»cd bc mcntio»cd that it has bcc» s)toto> that: ttio-dime»sional mode)s suclt as PLUSII may u»dcrcstimatc t)lc response ai t)Lc top of hc strticturc b>'0 to 50 I>crccnt. 6. 1 P' ) i k II I 1 1J '1 ~ ~ ~ In tippcndix D-LL38, comparisons arc prcscntcd of thc respons. for a fixed base and an SSI model both computed using PLUS)i and thc Wcwmark free-field spectrum (without tau-filtering) as contre motion on thc free-surface. Assuring that thc results presented arc internally consistent, it is possible to draw some tcntativc conclusions. Fig. 38-2 of Appendix D-LL38 indicates that thc pc. accclcrations on the containment cxtcrior obtained including thc SSI effects arc approximately 10 percent lo»er th n those obtain~ on a rigid banc. Since the SSI results automatically inciudc t).. effects of scattering of waves by thc foundation as well as thc effects of radiation damping into thc soil, it may bc concluded that the red«ction of 20 percent (0.75g to 0.6g) by tau-effect proposed b> i4ewmar): and a similar rcd«ction used by Blume arc Figs. 38-3 and 38-1 of thc same Appendix indicatnc'onservative. 'hat the story shear X'or"cs hand overturning moments on the con ment cxtcrior obtained inclbding the SS1 arc equal or slightly than those obtained thc base PLUS)l model. In hig)ici for I rigid this ease, any rcd«ction of thc fixed base results by ta«-filter'ould underestimate thc 'stresses in thc str«cture, Assuming that the PLUS)i rcs«its are correct and consistent, it may bc concluded that thc tau reduction proposed by Nc»ma~)'tlumc overestimates thc. rcd«ction effects of wave scattering an:l soil-structure interaction 1or vertically incident shear waves. In particular, thc st~csscs computed on thc basis of spectra rc- duccd b>'au-iiltcri»g would undcrcstimatc thc strcsscs that re- sult from thc SSI PI.US)i anal> sis by at least 70 percent. 7 ~ I l m l i t The ap))licant has indicated that thc shear wave vc)ocit> thc site exceeds 3600 ft/scc. Thc low-strain a»d iterated (or strai» dope»dent) shear waves vcloci ties used in thc PLUS)) SS I model are not rcportcd. I rcquc" t that this informatio» be r;;.d avai lable . In Appe»dix DLL-15 (Amc»dmcnt 53), a uni Corm she» r i.avc velocity of 3500 it/sec. is used. I recommend that thc tau-fi).tcri ig approach bc elimi»atcd and that a complete three-dimensional soil-structure an; 1;.sis vertical and hori "o»tally incident Sll waves bc u»dcrta);c». T)>.'.. approach wi11 have thc advantage of producing realistic cstima'. of the wave scattcri»g'a»d torsional effects. 4 The pea):-spectral response for thc PLUSll fixed base a»al>: at a Cr i»die'hat t)ie.1$ percc»t peal: wide»i»< of f1oor rcsponsc spectra o» low frcquc»cy side is »ot suCCicicnt. 5. Seismic Rich, A»a).vscs. Several seismic risl: anai>'scs 'thc )>iablo Canyon site have been pcrCnrmcd. Thc estimates oht; for thc probability oC cxccda»cc oC th« llos gri design spectrum fer by two or 'instrurie»ta'cceleratio» of 0.75g reduces thc probabilit> o':. cedancc by a factor of- four, (iij Thc usc of Dlume's SA~)-IV and SAM-V attcnuatio» rc- intro»s a, opposed to t)ic usc of thc Trifu»ac's rc latio»s leads tn reduction of the probabilit>'C cxceda»ce by a factor of tc». (xiij The rest. of the diffcrc»ccs corresponding to a fac- tor of 2.5-4 can hc attributed to, thc diffcront seismicity models co»sidcrcd. )lavi»g isola tcd the causes of the discrepancies in ris1: cs i matxon5 ) 4'i ll discuss them L» detail r I have i»dicatcf) that 'reductio» of thc peak accclcratio» to an 'effective'cvcl 'hcu'ot bc used in thc analysis of- nuclear power pla»ts. 1'or t)ic pose of cstimati»g thc ris): of cxcccfli»g thc )los gri dcsig» spec:" I I )I the a»chor accclcration of 0.7Sg should bc treated as actual acceleration. I» this case, thc probability of cxccdancc in 5i'ears as obtained by Blumc's analysis would bc of thc order of pcrccnt (refer to Table 11.S, 0-LL 11} rather tha» 0.1 pcrcc»t Thc main source of. diffcrcnccs in seismic risl: cstimatcs e be associate.cd with the type of acce3cration-ma@»itudc-dista»ce relation used. The applicant's r'isl: analysis is based o» th" of thc 1)lumc's SAW-IV and SAW-V proccd»rc. In my.opinio >, ti.;.: procedure leads to acrclcratio»s < hich do not reflect the st'. c . motion in thc near source region of large magnitude earthqua»;: If onc considers .the three lar< est, earthquakes for which rcecr.'.. werc obtained in the near source region, one finds that thc o!'crvcd pea); accelerations arc three to tc» times larger tha» predicted by thc SAi~) IV-V procedure (Table 2}. Since the sta»'. dcvia tion for pca); accelerations corrcspo»ds approzim tely to factor of two, it may be co»clue)cd that thc SA.') proccdurc is vali 41- shows 'that thc usc 0 f t)i'c SAM pro ccdurc 'leads to probab i 1 i t i . that are ) 0 times lower t)ia» those obtai»cd on thc basis of thc Trifu»ac's rclatio»s for thc same seismicity model. Thc scis»:i- city model described i» Appc»d'ix D-LL ll leads thea to a prol.ab'. ity of ezcccdi»g a pca); accc)cration of 0.7!'g in 50 yc"rs of the or 10. The seismicity model used in Appc»dix D-LL ll is bascfl on seismic rccurrcncc rclatio» obtai»cd b> Smith for Gcntral. Coast;; California (Appendix D-I.I. 11A). Thcsc rccurrc»cc relations are based on thc scisuiicity during the period 1930-1975 and do not elude thc 7.2ti 19?7 earthquake i» thc region. The rccurrencc c" as shown in pig. 11A-2 of Appe»dix D-LL 11A undcrcstimatc thc »umber of carthquakcs with magnituclcs larger than six, and are based on a nomi»al value For thc» framctcr b of 0.92. Addi tin'. study b>. Smith (Appcn:lix I)-I.L 45A) indicates that a morc apl.rc;". atc value for b would bo O.SS6. Tho paramctcr b w)rich cont.cls xolative co»trihution of the high magnitude carthqual'cs to t).c seismicity has a strong effect on the calculated risk. The usc b=.0,886 would i»crease thc calculated probabilities b> a facto &no (refer to Table 15.3 of Appcndi.x D-LL 15) . Thc seismicity model considered in Appc»dix D-LL 11 is c'nr tent with the seismicity obtai»ed in Appc»dix D-LL 41 ~ using:!::. geologic record of fault disloca'tio» (a- 3.12 in D-LL ll, a=-2. SO based on 10 years record and acs 3. 20 ba" cd on 0 x 10 6 years record in D-LI, 41). The scismici.ty calcu]atcd on thc basis of fcoionic record of lctcrcl fnult slip doc" not inc.'nJc city associated wi(h vertical slip alo»g t)ie llosgri fault. Iia- i (Appc»dix D-I.L 11A) quot cs a rcport b> Llorlh Science Associates dicati»g 'that thc „tlat eral sli p was probabl>'ubordinate to vcr; movcmcnt.'f t)>is is thc case, t)ic seismicity should bc incrc", to account for vertical slip. Con"idcring all thc factors mc»tioncd, it sccms that thc 11. I I probability of 10 to 20 pcrccnt iri 50 years obtained b> Andcr: and Trifu»ac properly rci'lccts thc cismic risk of cxccdance o> tbe llcsgri design spectrum. 12. I P.EF EREt! C ES Sci" mic L'valuation for Postulated 7. Slf ilosgri Eartf)quikc, Units 1 and 2, Diablo Canyon Site, Pacific Gas and Electric Company. Tri.funac, ff.D., "Pr(1iminary Analysis of thc Peaks of Stron<. Lar thqua k( <~fo t ion- f)open Trifunac, i~f. D., "I:orccas ting t:h" Spcct'ral Amplitudes nf Str< Earthquake Ground !lotion," Sixth t<'orld Confc) c:)cc on Ha) th ~ quake Engineering, Hetv Delhi, Indi a, 1977. f!c) mark, f!.if., "Torsion .in Symm trical Buildings," Fo()rth f)'orld Confc)'ence on Hart:hquakc Enginccring, Vol. II, A-5, Santiago, Chile, 1969. Anderson, J.G., and ll. D. Tri funac, Uniform Risk Absolute Acceleration Sp..ctra for the Di b)o Canyon Site, Cali forni:: A Peport to thc Advisory Cotamittec on ltcac or SiCcgual'ds, U.S. Nuclear Regulator> Co-,)mission, Dcccmbcr, 1976. 13. l YA13LE l. COM Ph)t)SO)A Ol Mh.:I')Uu C)%OUI'ID MOTIOYS I'ca): 'va IU c!L w = 6.5 uacd by 1 N V (ILL/OCC) ?3(dG) 39 39 (8'a ) 771!LX G(19) 12(30) 'cvnmark, N. M., "A )iatiollalc for Dcvclopnlc!lt of Design Spcct: a fnl''i= Canyon lkcactor F'aci)ity," A)L)lcndii C, SLLp))lcmcllt X!Lo. 5, SEA., ))L ~ ~ Canyo:1 )Nucleal'ov:cr Static» ULLits 1 and ?, LNRC, )976. AvcraGc (avcl agc + otalldard dcvia!ion) peak !notion for rock at all <:picc:lt diQtallcc It = I o5 )CN baricd 0!l ) 1'1 U'lilc, l.i, D., "Prc)L!11)nary Ana)". of t)LC Peaks of Stro!L!; !..ar))L<) uakc Qvo tio!lop D S iS h ~ 66i ~ 189 ? )9 (1975). 3 Paf',c, It.. A., ct il., "Ground li)oiinn Valuca for U.".c in t)lc Seismic D< Li) . of thc Tra» -Alaska Pipe)inc Syo)c!11," Cco)optical Survey Circular 67 c., 197 Z. t 0 I 't J ( ~ i~ ~ Ca a %~) SIi o/ i V~ AEk ~ ~ 44 Recorded Pred cted Ratio Predicted Ratio Pe-k Peak Ol)served/ Peak Geese.vcd/ Acccl ~ Accel. Predicted Accel. Predicted 1971 Paco ma( l. 25g 0.12~kg 10.08 0.859g '.49 1967 Koruna(2) 0.65g 0. 213g 2. 96 ~ 0.765g 0.82 1976 Gazli O.SOg 0.190g 21 0.900g 0.89 5.75 1.07 (1) h!=6.5, ep'ent-"1 distance 5 k~, focal depth 15 km. (2) H=6.5, epicentral d='stance 5 kr,;, focal depth 5 k-,. (assu"..ed). (3) '>~I =7. 2, epicentra 1 distance 10 kn, focal acpth 25 k>~. (4)~ V~s=12,000, E=Z.O 4,g =o (5) s=2, p=0.50. ( 1 l L l Vcloci(y, in. /acc, ~ '1 I ~d'O g0 gb t) ~ l) ~0 ~b c let P4 ~ A JI ,n A I'5 * 0 'Ji n ~Q b gc, ~ „'o4 p 4\ baI Ps e l J 0 p A P,werc q= ' Roc,(.. <= 7.5 8;q. (7r', m >>~~<) ~< = '-> 2.5 v p 'pg~ g)gp- ~ g. )~ (g g) ( QQM&O. rc. > 7) ) t.5 Qi lI E.O O.f o3 (} p o. ~ O. ( (i~~ C.) I h' ~ ~ A'aaron. ParrV I +Z ~ ~ I OP OP'O% 7W/lV/v1C Ã7 E I f)an, nrnr6 fxX ~ I ~ I ~ I ;l t I I l I ~ I I BA~ I I ~)XFD Blvd I, ~ I I ! ~ I 1 5'S7 ~LUSH I ) I I I I i l~W l I ': ! l I!' l I I 1 I !I I f '4 l l 4 ]p4 :/ I ~ I/ I I " I' tgj~n/ ) +J . I I J J 3 . tl)osc t:hc.y <'t per fc>rn) '(I s1);)13.ar (tn