ML20215N074
| ML20215N074 | |
| Person / Time | |
|---|---|
| Site: | 05000000, Diablo Canyon |
| Issue date: | 04/21/1976 |
| From: | Stepp J Office of Nuclear Reactor Regulation |
| To: | Beeston T CALIFORNIA, STATE OF |
| Shared Package | |
| ML20197J003 | List: |
| References | |
| FOIA-86-371 NUDOCS 8611040247 | |
| Download: ML20215N074 (1) | |
Text
f
/*
']'
f i
- y.
APR S 1 #I0
.~
Mr. Ted Beeston California Energy Connaission 111 Howe Avenue Sacramento, California 95825
Dear Mr. Beeston:
Pursuant to your request, enclosed, please find the most recent USGS " status of review" reports on the Diablo Canyon Nuclear Power Plant-site. These reports represent review of the latest studies conducted by utility.
5+
Sincerely, i
J. C. Stepp, Chief Geology and Seismology Branch Division of Site Safety and Environmental Analysis
Enclosure:
As stated cc: w/ enclosure f
W. Gammill i
- 0. Parr D. Allison
. v DISTRIBUTION:
CENTRAL FILE NRR RDG GSB RDG DSE RDG e
\\
l 8611040247 861023 PDR FOIA HOUCH86-371 pgg DSE:GS
\\
ar'ic.,
g JCSteph:sb
.u.....,
..,.[
4/20/76 l
,r= Arc.na <n 9.ssi Ancu o24o
- u............,.
.... o,,,..
4.,....
--..o
e
)
SEP 14 1976 locket 'os. 50-775 and 50 ~1?2 ecific C s an ' flectric emnany (mp:F) hrlicant; r 3
r.rer ">tation, " nits 'I and 2 c?cility: Diablo ranyon !'ucinar o
('f a? lo Canyon) 3D,41AP.Y OF MFETI!C l'El.P, 0" AUGilST 27, lo76 TO DISC"S", " TIS"IC DFSir.N qrry?! "S. TIT
c rot i i th tM. apolicant on Su"ust 27,1"7F to discuss thn seispic lesicn rrevaluation. f list of a ttenrines is provided in the Frclosure.
"'i'r van reevaluatin't the seisric design capabilities of the niant in tems of an earthonaka that was rare severe than the original desinn N
cart 5 nudes.
In tSis connectioc, Dr?E bad disc issed t's status of tt'c reactor coolant syston reanalysis at an Mvisory Comittee on 'eactnr Tafn 'uards (fsCp") suFcomittee re etinn on Jeno 25 and June 26,107E.
e r"*" tec' t en :rs to.! this 'v etinc ("noust 27,1"76) to (1) rmvido tho s tTFf ' ith an undate on the status o' the reactor coolant systc~
raaralysis and (?) to discuss the reactor coolant s."stm reanalysis
'i t'! intere".tod staff n r+ces i*o had rot attended the TCP." sut co 1'ittee
..m tino.
M'F an ! '!es tinoboue,o s tated that thr aralysis results had so far irdicated that t% reactor coolant svstro would rmain within t'~ faulted condition
. stress linits of the AS:tr " oiler an.1 Pressurc vessel rode.
(The staff had nravinutiv irMeated t'$r t these linits " ore accontablo criterio.)
Thn analysos had so far Fren Fased or tho follot'in":
(11 t
" ro v a. ' res ense s ectro: racom 'nded tu rc'r 's conr.ulta".
Mr..hhn '. P1'r:c.
I
(?) no reductin'1 in tFr orcund responst spectr!'n d"c to non-linear (dectilitv) af#ccts.
(3) con'.inine aarthqual:e lands t'i th lo's-o#-roclant accident (I C"f I loads bv the snaarc root of t' o siri of the sonaros method.,
)
t c
./
J
- = "a
- l.
- v - *
.__i_,__
.fy..
- d. :.'....._.
.u>
D,k lW r== ABC.)ls (Rw, 'p.W ASCM 92M
-W y, s.novessement sensanne orness ten.seentee
.A M
J s
)
SEP 14 376 "qq and '.'es tinnbove.a noted that if the staff shnold rocuire sionificantly norn severo nrourd res?onse snectra, it rit;ht Sc necessary to nerferr a more con'ler analvr.is hich rodelo f the interaction %tveen t'e reactor coolant syster, and its sunnortinn struct"r.>s.
euch an analvsis veuld yield lower calculated stressrq in t'c reactor coolant systrr than the mrnal aaalysis net 50ds. I'0"?ver it veul,' take about o-e year to cccrictr. such an analysis.
'fr tiiscnssed the possibility (Fat the staff richt accent a raductio" ic the cro.'nd rosronse spectrue due to non-linnar effects. This richt offset a renuirer ont for a more severn around response srectrue'.
PC*.E and "estinchoue.c noted t**at th' calculate >! strrsses dun to tha cart':0,tnho vere well t elo" t' n faulted co :diticn stress lirits.
It van nnly if ter carthonake stresses eera cor'fr.ed with stresses due.
to a restulated striultaneous UCA that t'm linits parc apnreac'"d.
'ccordingly, they could s'w accertalle stress levrls usi-o the nomal analysis net 5cis for even the r est sovern of nround resrenso spectra currently un.fer consideration if they were not required to assir+
a struitaneous LOCA.
g "e discussed tSe Tossibility of rot cor'ininc onrt4cua!:r loas Mth I.^C' Inads for t8 e corroses of ti o seismic desirn reeval"ation. The ra tionic for t'.is c^ul? & n thc t, i f t' r cartho"r.f a does ret nynrstrm tV re..ictor coolant syster, it sho rld not cause a trM.
I t 'i f ro t s v-libnh hoorver, tSat this arOrnach ' o"ll ' e es"d.
Tbc scuare root nf t'.n sun o t'
sonares na tho ' o f co ' inin, c;" t' ona' c r
an
- f TA low!s (u'tich t'.o a nlicant 'ed t arn ur.ing eo far) r prMcote d sire ralantion rela tive te norral Proc"dur'.
"o ap"licant fel t t' at this coul.f hn f.cchnically.imtif f r.'
and niannod to e.ut rit tho iustification for it ir t'c futern.
Original Signed By Dennis P. Alliten
^111s.n, "rn.inct
'n r# m r 1"ot hter 'rac ters "rarc'
'c. 1 ivig ten of rrn4act '9nsc ri nt
"* c]qcor**
r
?. e.
r 3 g g,.s cc:
racific ^.as and fle.ctric formnv ETTP-
'fr..'nhn r. "errissev
'llce "rasident ". Cenrral counsol 77 f.nale Ctreet San Francisco, California 0/l'E L
L
- 1 e n. *-
.~
\\,
.DA son /LM J
..,. + - 9L1.3 1&.2C.
06'
'w.
W
-. =. +
.*..........n...,...-
=.mi..m -.=,
1
e t
i tg SEP 14 1976 cc: Philip f. Crane, Jr., Esq.
Mr. Villiam P. Cornwell Pacific Gas and Eloctric Company P. O. Box 453 77 Beale Street Morro luy, California 93442 San Francisco, California 94106 Mr. !!. J.1.irdblad, pro,1cct Engineer
.a drew.1.
Staff, Esq.
Pacific r s and Electric Company n
a California Pubile Utilities Comission 77 Peale Street 350 McAllister Street San Francisco, California 9410<
San Francisco, California 94102 Mr V. C. Ganaloff
'fr. Frer! crick Eissler, President t'estinqhouse Electric Corporation Scenic Shoreline Preservation P. O. Cox 355 fonference, Inc.
Pittsburgh, Dennsylvania 15230 ar23 '! ora Mesa Drive Santa Earhara, California 0310'i Mrs. Thelra I!irdlar Cll Fair Oaks Avenue
'!s. Elizabeth E. Apfelberg Arroyo Grande, California 93420 1415 Cazadero San t.uf s Obispo, California 93401 w
!!s. Sandra A. Silver 565K PMford ".venna
" ort', llolly, nod, California 91 6'17 "r. Cordon A. Silver 5055 Dadford Avnnuo
" orth Pollymod California 016n7 i'aul C. Valor tina 400 Channing Avenua Palto alto, California 9d301 Yale I. Jonos, Esq.
100 Van "ess Aven'r loth Floor
'hn Francisco, California 0"102
's. 91.uc ri e,,i nn 17V Chorro Strent Mn ! nin Pt ispo, Olifornla "T101
'Ir..inhn corster Wi Paln Street Sa n 1.u i e. Pbisco, California 93401 orrece >
euammus >
+
^
'en ts k
.......l.
e--.-+
2---
~~
~
^,.
8 A84 *ovsmassent pasNtesse eersees to,s.ese. tee.
pseu. ABC Sie 3Rev. 9 93) 4BCM 0340
- ~
EJ! CLOSURE LI,E 0,F ATTENDEES PGAE
!!. Lindblad Uestinghou';e
.1. Dorycott T. Esselman
_?M_ C_ Staff.
J. Knight P
Y. Chen m
- 9. Allison I. Sihveil K. Vanur R. Itofnan emea >
suseasee>.
......._.......,u...,, h-
-.. J '.,:..
.....:..~".
ontaS
.Poes ABC.)t5 (Ree, p.9 9). ABCM 0240
. -# v. s. sovannseewy pnewtewe om. e.ss sete.sas. nee
o l
MEETING SUMilARY DISTRIBUTION
__nne'.t e n n _
J.. Knight NRC PDR D. Ross local PDR R. Tedesco TIC S. Pawlicki NRR Reading I. Sihweil LWR 1 File P. Check B. C. Rusche T. flovak E. G. Case Z. Rosztoczy R. S. Boyd G. Lainas R. C. DeYoung V. Renaroya D. Skovholt T. Ippolito J. Stolz V. Moore K. Kniel R. Vollmer
- 0. Parr M. Ernst W. Bu tler W. Gammill D. Vassallo G. Knighton L. Crocker B. Youngblood R. Clark W. Regan T. Speis D. Bunch P. Collins J. Colli.ns WWW4h@
C. lleitemes W. Kreger R. Ifouston R. Ballard S. Varga
'i. Spangler J. Miller J. Stepp F. J. Williams L. Hulman R. lleinonan H. 99 tth II. Denton V. Stello D. Muller P. Y. Chen Project Manager K. Kapur Attorney, ELD R. Hofman IE Tom I! irons E. Ilyl ton Saul Levine llRC participants ACRS (16)
D G
,p.
9,
)
AL 3 0 1976 Docket !!os. NO-275 and 50-323
?pplicant: Pacific Gas and Flectric Conrany (PGAE)
Facili ty: Diablo Canyon f!uclear power Station, Units 1 and 2 (Diablo Canyon)
SUMMARY
OF ADVISORY COMMITTEE 0?! RFACTOR SAFEGUf RDS (ACRS) S"DCCmITTEF "EETit:G CONCER? LING Tite DIABLO CANYON OPERATIt!G LICPISE APPLICATION The ACRS subcormiittee met in San Luis Obispo, California on June 25 and June 26, 1976 to discuss the Diablo Canyon Operatirr!
License Application. A list of attendres is provided in the enclosure.
Background
m PG',r had applied for operatinn licenses for Diablo Canyon in 1973.
Construction of Unit I had essentially been cmpleted in april 1076 Powever, the review of the operatino license application was not yet completed due to delays associated with evaluating the carthauate rotential of the l'osgri fault. This fault, located about 31/2 niles offshore from the Diablo Canyon plant, had been discovered after th-construction pemits for the Diablo Canyon units ware issifed.
On May 11, lo76 ue had formally issued our evaluation of the carthquake potential of the Fosgri fault. Pased on a:, assessroent by the US Geological Survey (USGS) we had stated that a nagnitude 7.5 carthonoke should be assumed to occur on t5o l'osori fault and had requested that the applicant reevaluate the plant's seisnic canabilities accordinoly.
This carthquake is more severe than the earthauakns for which the plant was cricinally desiened. 41thouah PGt,E had not anreed with our assessnent of the Hoscri faalt's earthoude rotcntial the corrany was nrocredino with the reevaluation as wn had requested.
At a previous subcomittee reeetine on t'au 21, 1076 the crolory and seir.nolony had been discussed ani sone of the snisnic desion aspacts had been discussed. At this m:etino (.hnic 2F. and June PF) the rmainder of the seist,ic desian aspects which had been developed to date wero discussed.
[()2 O P NC B >
Eu mas a ug >
'O A tE > '
4 u. e. novsmausset Pasuvinte errects es,e.sae-tee,
Isthe AIC.IIS OlfT. 9-13) ABCM 02 40,
O.
) JUL 3 0 1976 Se_isnic Desian Ue presented a discussion of seismic response analysis an! the differences between the approach that we intended to accept for the Diablo Cenyon reevaluation and the approaches which am norrally-employed. The two pricary differences which the staff had adopted were as follows:
(1) In the Diablo ranyon reevaluation it would be acceptable to take credit for a small anount of non-linear or inelastic behavior.
(?)
In the Diablo Canyon reevaluation it would be acceptable to revise the design response spectrum, depending upon the equivalent length of buildinq foundations, in recognition of the lack of synchronization of ground notion waves beneath structures during earthquakes.
Dr. John Blur.e, consultant to PGSE, discussed the desien response spectra (ground motion) to be used as an input to the engineerina se calculations in the reevaluation. He provided preliminary recorraended spectra, based on analyses of the available records for ground notion due to nearhy earthquakes at rock sites. Dr. 31une also discussed conservatisn in the seismic design of nuclear power plants and conpared it to the seisnic desien of schools, hospitals and othar irrortant structures in California.
Finally, be discussed the historical experience with th eerforrance of struc?.ures in actual earthq' takes and related it to nuclear power plant design.
Nestinghouse discussed the results of studies of the reactor coolant syste" which had been perfomed based on various assumed desien response spectra.
Altbouqh the Westir.chcuse studies had not yet been subnitted, Pestinghouse intended to proposed and justify combininc the loss-of-coolant accident loads with the earthquake loads using the souare root of tSc sun of the squares instead of followinq the usual procedure which consists of codin, the absolute values.
It arpeared thrt, if this approach is used.
the reactor coolant syster would be able to reet th< faulted condition linits of the FST Poiler and Pressure Vessel Code without the necessity of nerfoming a tinc-consaning inelastic analysis.
3r. pathan Newmrk, an ':PC censultant, presented a discussien of to seisnic desion bases to be used in the reevaluation. The U.S. Cenloaical Survey had specified the ground rotion to be utilized in tems of acceleration and other valuns that would he masurad by an instrunent h the free field. These values did not account for the nresence of structures or the nature of structural responses such as non-linear energy l
OmC E >
cu nes a na r >
= = = *
-.,._.a Foran ABQHe (Rev, p.53) ABCM 0240
.* u. ea sovsmansassy paiemme opricas so,4.sas-see.
F' I
i f
-3 E L 3 0 1976
(
absorbino nechanisms in structures. Dr. Newrark had determined the effective acceleration and provided tentative design response snectra to be used as an input for engincering calculations. He discussed the bases for this work and related the tentative spectra to observed 9round notion data and structural response data from actual carthquakes.
Or. *!evnark also comared the tentative recomendations to the seismic desian bases used for critical structures other than nuclear power plants.
}
SchedulpfFuture,j'pe, tines The tentative design response spectra which had been developed independently by Dr. "ev.rark and n. Blu::'e showed substantial r
similarity but thara were sorv) differences between ther1. I!e noted 1
that our final conclusions on the spectra would not he available until
'.e and Dr.1etrark had reviewed a specific proposal, with justifications, ubich PG"<r was expocted to submit in the near future. After the final conclusions had teen nade concerninc the design response spectra, the reanalysis would be ctrmleted.
$xA 4 full 'C5 neetina was scheduled for July 8,1076 to discuss the raterial ve had presented to date at the subccrmittee reetinas on May 21 and.h ne 25 and 26. Further racetings would he schedulrd when t
the resul ts of the rearalysis of the olant were available.
Original signed By Dennis P. Allison
'i. P. Allison. Droiect Manager i
Light Uater Reactors Cranch Ito.1 l
Divisien of Project Manaaement t
inclosure:
{
is stated cc: Service iist i
l
_... LWR #
-..L
- 1 4....-....
eu.~.-..-
DP ison/LUL. J l
07/MOZ6_..
._07/j-7176
.. v m...... - m.
[
3. ' 1:
)
EUCLOSilRE List of Attendees June 25 a_nd iune 26, 1976 T
ACRS HRC Staff
- 3. Okreat - Subcommittee 'Chatman R. DeYoung J. Ebersole K. Kapur D. Allison ACRS Consultants I. Sihweil
~~~
J. C. Stepp T. Fickel
- 11. Gamill J. !!ilson R. ifofriann
- l. l'hite G. Thmnson
'flC Consultants _
f,CRS Staff J. Devine - l!SGS
~~~
F. *1cKeown - !!SGS J. I'cKinley N. Newnark - University of Illinois w
r:. Ba tes T. Hirons - LASL id nhers of tha Cencral Public_
PGtE_
e
'!. Lindblad A mr:ber of interested persons R. Dettinger from the general public were T. 'loutz present. Mone made staterents
- 31. lioch to the subcornittee.
J. Ghornley J. Skylar P. Crane PCnE Consultants J. Clune
- 4. GallagPer D. !!ar-ilton S. Sr.ith I'estinchouse U. Gangloff P. Lin T. Esselman orrsca >
~
(UnM A tes >
onts >
Foran AEC 318 (Rev. 9 55) A.ECM 0240 W u. s. eovannissur eniarine orrics sera.sme-see