ML20234B962
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E. G. Cace, /coistant Directer.
September 17, 1963 1cr Facilities Licensing
'Odginal Signed W helert 11. Bryan, Chief gq eriH Bryg F.eteorch & Fover Eertetcr eret;/ crer en Irivisica cf Licenaing & Beguietien Co.WT5 05 BOIWGA APPLICATI02, DOCKET NO % 205 It the etrious, discuccicne. c1lthe ecrthquake cecign criteria icr Ecdege with our ceraulte.nts, it ha.s t,een c3eer frcm the very teginninE that cur ccesultents hac no rs.jor reservaticos with structures (in rerpect to the requirement 6 f or the cerign of.
which inotences stress leve16, deflection 4, or. perraonent,.et veuld te the limiting factort). Thia. was the case even thcugh Mr. Neumann and Dr. Nmnark t.ad teth indicated that an earth-queke cf the order cf intensity of the San Francisco 1906 Quake, if it occurred in the vicinity-cf Ecdega, would result in grcund motions having neximum acce'. err. tion in the steightcrbcod cf 2 3E
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in rock (compared to PG&E's estiraate cf 1/3g).
At the mesent, it appears that even though PG&E'4 proposed criteria in Aa:endment k are vogue they vill te received to tre eatisfacticn of cur censultanta insofer es structursl integrity is: ccncerned. Irca Dr. Nevaark's drs.ft report and his crel reir. arks, it it. clear that this is ac Lectuse he telieves that structures deeigned Ly these criteria vill, ty virtue of the conservatism of the design method, have cutstantisi reserve strength with e 2/3g earthquake.
It is etvicus te me that nimile r expert r.ttentien has a et Leer given te those preblems of design in which stress, deflecticn, etc. sre not the limiting fceters of ccr.cern.
It is etvicut.
also that PG&E's. vcgve propeat,1 (ir trendment k) to design certain " critical equipment and systems" so as to *be espable i
cf bringing the unit to a safe shut dern" in event of a 2/?g earthqueke doesn't provide, in itself, eny expressed er implied cena.ervatiam ccupe,rstle to the ecnservatism that cne is assured te tave in structures.
'h: other wortis, there is no margir: for l-misjudgment er error in estimat'ing the' gmund motion of earth-quakes, in designing to provide the desirhtle functions in the event cf that earthquake,' or to account for deficiencies in fabrication ar.d installation cf ecaponents whose operation ma>
Le adversely affected by the inertie.1 effects of earthquake motion.
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,. Ac I. ederstr.nd PG&i.'s prepccal,' they vill assure thrst the plant s<ill te capatle cf teing trcE6ht te-c ente -stut ccvn in er.rth-quakes resulting in acceleration i.n te, i et net In execst ~ef Aseuming thet "tringir6 the unit tc r ief e thit dcwo la 2 36
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/intended to incit:de sLtisfcctery e:;.ercency ' reticivhich tight te required in the event cf cny creditic occideat,.cr.e z.at then
'j extcir < critically the ecncervatica cr relialiliti c.f ctar j
ecliective past estimtes.cf expected ertrthgehe: intenoity' at tt:13 f
.ite. : At least three percent who erc etncidered te te experts cr, this qcestien haYe eXpreD8ed,judfaentt cL th15 peint it. the pest!
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- 1.. Mr. Neu: ann estimates from u.e:instion cf scinc3c6 c81 1
reconis that tasement rock ructicn c.t Ecdege from n' 190ti type esithquake in tLe vicinity cf the site veuld.
invcive ground.seceleraticr.u-in the ran6e of J to 1.0g.
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Dr. Nev:i: ark, f rc= hi:: c+n experier.ce, ht,
.trtec thet the intensity of the expected ncxinus :rotica, in teras 6
cf accelerations end velocities, :rj 'ce tchen es clout
. tvice that of the north,ceth etaper.ent ef meticn reccrded in the El Centre c6rthquote.
3 Dr. Bauener in the aceting et A% Jay 2,1%3 ccmmented en the tosia cf hia rece:zende.tien that in additien to elsatic decign tcing bisaed q.cn en
" average 11 Certro spectruc" with caximum accelerc-k tien in the neightoWood ci -li5 to 1, Ag, a further acalysis should te mde to insure thet groced :acticn five times es intense es thir. desig. Spectrum veuld 1c reqcired to produce incipient it.11ure cf ctructures.
i (Tbis criterien vec preperv6 in Arend:sent }. )
Dr. Bausner steted tl.at it vra the intent ci thia require-ment that the specified structures le enclyred vitt accelerations, velocities, etc. five tizaes the c!esi6n values (i.e. acceleraticca ci 1 te ldg). He stated and reiterated that his 'cNective in propccing this criterien ve.s to make it extresely unlikely that strLetural members vould fall on and insett the perfemance cf-equipment end,systeras vbich are ecsentie.1 te nuclear safety. He stated itrther thet he censidered the facter cf 5 to.t reasonable frez en engineering viewpoint to J
take into ecccunt (a) encerteinties in'esticating the intensities of actice of certhquakes; (1) Jack of
' precision er mis.4,udgment in reking the nructural design; (c) imperfecticne in materials;end (d) errors in constrtetion.
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It seese to r.* that if Dr. Ecuaner is so cencerned clout checkinE
. structures at 1 to'idg to ' assure that they den't fell en end prevent socae cefety actiec, we should le interested in seeir.g that cefety-essential components are devi6r.es (nd ccnitracte:2 cc es to le opereble in.tte event cf ground c.cticn6 et 3erct tns t intense.
It dces not,eem to :rcke any senne et ull. tc thick ci protecting an essential piece cf equip. ant (as Dr. Ec Laner recommended) fer hepond. the point at which it has ultenQ iciled.
Dr. Housner indiceted that be. did not ette:;.pt tc. edsiae PG&E except with respect to atructural design a.atters. Our centultc: to, likewise, appeer to hs-ve given toc little ' considersticu ' tc proi.le:::,,
that are not related te structter.1 design. :I Lclie'<e it 'imperstive that we obtain expert advice on the particuinr stiject cf the ultiente design criteria icr.ccupcuents in which structural te-havior (utress levels, deflecticn, etc. ) r.cy retle the limiting fa ctor. I telieve also tha t we must have e aiuch greater tuder-standing of the methods t y which cencervative compcnent decign
- 'e should. have advice, for instence, cn the een te achieved.
EpPlicetien of existirg military cr industrial specifier.tiens on shcck resistant crucponents and en the need fer specic1 shock testing cetheds fcr ec:npenents to which euch specifications de l
not apply.
1 The fc11oving are a few examples cf equipcent snd cc:cpenents vhich l
vill be taed in the Scdega Pcwer Plant whae pericrance mey to I,_
affected by the inertial' ef f ects ci earthquakes:
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Check valves which are depended t.pon as iacistien velvea.
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Preer.cre regulctin6 vsivea enc oti.er pretatre cr shock censitive devices in centrcl and instrucenteticn systems.
. Contro] red drived.
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The suppreccion poel. S1csh116 rei veter in the auppressica
.peci vould di:ainish the beet or voter al.cie scos of the pipes from the dry well. Tvis would tend tc shcrt circuit the ficv of stes.m from the dry well.
cc:
R. L.'Lowenstein Suppl.
.F.
N.' Watsen R&PRSB Reading R. E. Bryan DL&R Reading R&PRSB,;DL&R J
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9[17/63 DATT >
Form AEC-318 (Rev. D43)
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sammant esinri.. omes i+-erial-s
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