ML20214U296
| ML20214U296 | |
| Person / Time | |
|---|---|
| Site: | North Anna, Diablo Canyon, 05000000 |
| Issue date: | 10/14/1977 |
| From: | Rushforth B CENTER FOR LAW IN THE PUBLIC INTEREST |
| To: | Moorman J JUSTICE, DEPT. OF |
| Shared Package | |
| ML20214U164 | List: |
| References | |
| FOIA-86-699 NUDOCS 8612090215 | |
| Download: ML20214U296 (3) | |
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Janas W. Moorman Acting Assistant Attorney General Lanc anu hatu al Resources Dividion CONFIDENT EL Justice Department Constitution Avenue between 9th and 10th Streets, N.h.
Washington, D.C. 20530 Re:
Possible Prosecution of Pacific Gas and Electric Company for Failure to Disclose a Geological Fan.t (18 U.S.C.
51001) l Decr Jim:
I h.ve before me the e.:'0?llent m orarfum preparad and addressco to you by Bradford T. Whitman, Assistant Chief, Pollution Control Section, regarding a pccsible prosecution of Virginia Electric Power Company for failure to disclece a geologicc1 fault in connection with the North Anna Nuclear Power Flant in Virginia.
I am writing to you to call to your atter. tion the 7.ossibility that Pacific Gas and Electric Company fai3cd over a period of years to disclose to the NRC staff the existence of the Ecsgri Pault near the Diablo Canyon Nuclear Pown-Picnt in San Luis Obispo, Californic.
I believe the evidence r,ug:csts t;.r.t Pacific Cas and Electric cce,neny krcw of th ?. exiMenee r" tS.c fault for perhapr two years before they disclosed its existence.
It is. highly prcbatic that if the information regarding the li: sgri Ecult h;.d bsen cisclosed to the NRC <.hortly af ter the it.tlt wct dia ;vered, th. constru: tion licenses ar.y never have 1:wd or m.y '.v.vc be.:.n rescinf:1 bafore cubstantial conrtructicn Lcgtc..
I segy.t you and your staff conduct en invertit*ation aimilar to thc investigation which you conducted with ree ard to the Ucrth Anna i'lant in Virginim e
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't I have enclo.wd for yout inf r a'.icn te-t:. mony which I oave before congre.sman ;'.m Udall's SLbecmmitta on Enercv 3
fyne ;10, 1977.
and the Environnent, regardirg th!.r sub ect en g
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a 1.AND AND N AT. REs. UlV.-
8612090215 861203 PDR FOIA Pollation :'cr.U;.; sec.
l DICKEY 86-699 PDR i% M - K - 0 1' 6/
Jam =s W. Moorman October 14, 1977 Page Two I direct your attention, in particular, to the chronology which reflects that the discovery of the fault by two Shell Oil Company geologists may have come to the attention of Pacific Gas and Electric Company two years before Pacific Gas and Electric Company disclored the existence of the fault.
During this time, Pacific Gas and Electric Company may have made false filings with the Nuclear Regulatory Commission and may have failec to disclose the material fact of the existence of the fault.
I believe a full investigation of this matter is appropriate and I hope that you will undertake such an investigation.
I call your attention also to the attachments to my testimony before Congressman Morris Udall's Subcommittee on Energy and the Environment.
These attachments are internal memoranda prepared and circulated among members of the NRC staff.
These memoranda are evidence of the NRC staff's irresponsible handling of information regarding the existence of the Hosgri Fault once it was called to their attention.
The memoranda also reflect that the NRC staff considered this information material, indeed central, to the issue of licensing Diablo Canyon.
The memoranda make clear that the NBC staff was considering highly political considerations rather than public health and safety matters.
This is highlighted on page 3 of attach-ment 7 where the staff sets out that in developing a progrcm to resolve the Diablo Canyon problem, consideration should be given to the impact of the decision on the nation's energy problem, the impact of the decision on the moratorium for che Californie voters, and the impact of the decision en other plants.
While the fault under the North Anna plant was small and inactive, the Hosgri Fault is capable of a much stronger earthquake (estimated by USGS to be 7.5 on the Richter scale) than the Diablo plant was decigned and constructed to with-stand.
Condocuently, its existence has raised a host of serious and unresolved nealth and cafety issues in the operating license proceedings.
Realizing that the Hoscri Fault and the safety issues it raises means serious trouble for them in the operating license proceedings, Pccific Gas and Electric Company has applied for an entirely unpre-cedented full power "interin operating license".
Jam.s W. Moorman October 14, 1977 Page Three The application is really an attempt to avoid the clear impact of the law and the regulations on the operat-ing license proceedings for the Diablo Canyon plant.
Consequently, the investigation, if it is to be timely, must begin at once by your office.
Pacific Car and Electric Company's possible failure to disclose the material fact of the existence of the fault has led to the situation where a 1.3 billion dollar nuclear power plant sits less than three miles away from a fault capable of an earthquake much stronger than the earthquake for which the plant was designed.
This situation borders on the tragic, not only for energy users within the Pacific Gas and Electric Company service area, but more particularly for members of the public who live in the communities near the plant whose health and safety and peace of mind are at stake.
In short, I fcel that this situation clearly demonstrates not only "a pervasive bias against the public scrutiny which a project of this importance deserves and is entitled to under federal law" on behalf of the NRC, but also possibly criminal culpability on the part of Pacific Gas and Electric Company.
I would appreciate hearing from you regarding this matter at your earliest convenience.
Very truly yours, pf01f j
Brent N. Rushforth BNR/cft i
l enclosure cc:
Bradford F. Whitman Assistant Chief Pollution Control Section i
s l
Testimony Before the f.ubcommittee un Energy and the Environment Regarding Diablo Ccnyon Nuclear Power Plant June 30, 1977 Introduction My name is Brent Rushforth.
I am an attorney and one of the founders of the Center for Law in the Public Interest in Los Angeles.
We represent scveral citizens groups and private citizens who have intervened in the NRC licensing
. proceedings for PG&E'c Diablo Canyon nuclear power plant near San Luis Obispo, California.
As you are aware, the Diablo Canyon plant sits just three miles from a n.ajor active earthquake fault located offshore, the Hosgri fault.
The fault is capable of an earth-quake significantly larger than that which the plant has been designed to withstand.
We believe it is entirely appre,rriate, fcr in light of catastrophes like the Teton Dem disaster, Congress to ask the question how this unfcrtunate circumstanca could come to pass if the NRC staff vere doing its job.
t.'e believe the circumstancas here dcmo:: strate that the reculatory staff has failed and continues to fr.jl to p ctect the public health and safety with regard to the Dichle Canyon plant.
This can perhaps be best ur.dcrstood in thc ctatext of the history of regulatory process rcgardine, the Dichio Ccnycn To assist memberr of the Subcommittee in understanding plant.
the chronology, 2 have attached a che.rt to this tec *.in ony sc-tting out the significant date.4 in the Dichlo Ccnyon plant ' r. hi r. tory.
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The NRC Stc!.'O Initial Site Inynstigau2On WD3 Seriously Deficient During the initial :".te investigation stage the NnC staff failed to follow leads suggesting the need for ad-ditional offshore investigation of possible faults.
Such suggestions came from Dr. Henry Coulter of the USGS as mentioned in an NRC memorandum dated March, 1967 (Attachment 1) and fron Dr. Robert _ Curry as set out in his letter to the C?]ifo'.i a Public Utilities ccmmission dated December, 19fC.
(Attach.ent 2).
PG&E's own consultants admit that geological and seismological data available in 1967 suggested the e::istence of the Hosgri f ault.
(Testimony at a meeting of the Advisory Committee on Reactor Safeguards, February 18-19, 1975; Attachment 3).
Nor can the regulatory staff argue that the scientific techniques for further offshore investigation were unavailable during the initial site pre-construction licence phase.
During the late 1960's two geologists employed by the Shell Oil Company using exploratory techniques offshore from the plant site confirrc.ad the e):istence of the Hosgri fault.
While not wishing to cry over spilled milk, we simply point out that a thorough pre-construction license investigation by the regulatory staf f may well have located the fault and the present problems nay have been avoided.
II.
Thc NRC Staf. Failed S o Infora Itself of Important Devclo;ces.tc Subsem.J.nt To 7:10 Issuance o: The
@Ertruction Licc:JcC'IX~pril, 196b for Unit 1 and December, 19)O for Un2: J).
The cxistene._ of the Hosgri fault was reported in the scientific li ternture in January, 1971 by two Shell O.'.1 6
Comptny geologiste.
But the regulstery staf..pparently did not become aware of the paper until August, 1973 when it was mentioned in one of PG&E's submissions.
(Response of MRC to Congressman Udall's questions at p. 8.)
This lapse of 2-3/4 years indicates the level of attention the staff was giving this critical matter subsequent to the issuance of the con-struction licenses.
In November, 1974 intervenors requested the Atomic Safety Licensing Board to issue a " work stoppage" order to permit reconsideration of the adequacy of the seismic design of the Diablo Canyon facility citing the USGS report of August, 1974 which confirmed the existence of the active, 90 mile-long Hosgri fault.
The staff claims to have assessed the earthquake potential of the Hosgri fault and concluded that the plant design was adequate.
However, the USGS was obtaining preliminary conclusions that the earthquake potential of the Hosgri fault was substantially larger than the NRC assessment.
The NRC staff failed to inform the ASLB of this fact at any time and instead opposed intervenors' request for a " work stoppage" order.
(NRC Memoranda of 2/11/75 and 2/20/75, Attachments 4 and 5.)
III. The NRC Staff's Present Lporoach To Licensino 5he Diablo Plant is Sericusly Deficient.
The NRC's sole purpose for existence is to regulate nuclear power in a way which ensures and prctects the public health and safety. The United States Suprcre Court has stated "that the public safety is the first, last, and a permanent _ -. _
i cansideration in oay dacision en the issuanc-of a ccnctruction permit or a license to operate a nuclear facility."
(Power Reactor Co.
- v. Electricians, 367 U.S. 396 (1961)).
Ho' wever, in regard to the Diablo Canyon plant, the NRC staff has become an advocate for the "as-built" design and its critically important role as protector of the public health and safety has been seriously diluted.
This is substantiated by internal NRC memoranda which outline a program for licensing Diablo These memoranda show that the NRC staff recognized Canyon.
" horrendous" problems created by the existence of the Hosgri fault, that the staff considered factors having nothing whatever to do with plant safety in deciding to press the case for issuing an operating license and outlined a course of action for licensing the plant as built which it has followed and continues to follow to the present day.
This would be perfectly acceptable procedure for an agency whose responsibility is to promote and advocate the development of nuclear power in general and the Diablo Canyon plant in par-ticular. But this is not the proper role of the NRC staff whose duty is to protect the public health and cafety.
Once the evidence of the existence of the Hosgri fault becane irrefutable, the staff recognized its serious consequences for the Diab]o Canyon plar.t.
The staff perceived that requiring the plant to withstand an earthqual:e (a so-called safe shutdown earthquake or SSE) that would generate a ground acceleration of more than 0.5g woulc necessitate extencive
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' backfitting cnd time-consuming re-cnnlysis cnd "horrende-(NRC. Memorandum 2/11/75, Attachment 4).
The decisions.
staff then spent almost an entire year in an effort to amend the SSE for Diablo Canyon or discredit the USGS conclusion that was greater than 0.59 (NRC Memoranda 2/20/75; 1/5/76; and 1/12/76; Attachments 5, 6 and 7).
Failing to discredit or amend the USGS conclusions, the NRC staff implemented a strategy designed to provide a "as built".
(NRC Memorandum basis for licensing the plant 1/12/76, Attachment 7).
This strategy included 1) proposing that the USGS review its findings, 2) assembling a team of cxperts whose function would be to reduce the g value of a and 3) turning out a potential earthquake on the Hosgri fault, This is the licensing strategy that probabalistic study.
staff has follcwed to the present day.
the NRC the staff con-In settling on the above strategy, sidered and was presumably swayed by factors having nothing to do with the public health and safety of the citizenry who will be affected by operation of the Diablo Ccnyon plant.
These non-safety factors included the following:
The impact of our decicions on the nation's 1.
The impact of energy problems and programs.
potential denial for operation of a pinnt approvcd for construction cannot be underestinated, especially where the basis for denial is in controversy.
The impact of our decisions on the moratorium 2.before the California voters.
The impact of our decisions on the viability 3.of continued opciation of plants at other sites such as San Onofre, with altered seis:aological bases, Pilg r in., etc.._
9 4.
The impu t of our decicions en tha 2cbility of continued operation.of plants where it is uncertain that the capability exists to withstand altered design bases in areas other than seismic design, such as containment structural design, pipe whip inside containment, spurious valve failures, etc.
(NRC Memorandum 1/12/76, Attachment 7).
The staff's concern for the politics of their decisions on Diablo Canyon distorted their entire analysis of the seismic hazard to the plant.
In June, 1976, the staff and PG&E submitted such an analysis to the Advisory Committee on Reactor Safeguards (ACRS).
A consultant to the ACRS wrote that the staff's presentation "makes a mockery of the seismic analyses and sets a dangcrous precedent."
(Luco, Enrique, Comments on the Proposed Seismic Design Reevaluation of the Diablo Canyon Nuclear Power Plant, A Report to the Advisory Committee on Reactor Safeguards.
(November, 1976)).
Continuing in its strict adherence to its program for licensing Diablo Canyon, the staff *now proposes to license the plant by obtaining an exemption from the applicable safety regulations.
This proposal would permit PG:E to run the plant for two years and determine during that time which parts need modification in order to be able to withstand the safe shutdown earthquake.
The regulations, however, require a showing that the plant can withstand the SSE prior to the operation of the plant -- a requirement that coincidcs with common sense.
PGsr and the staff propose to justify the exemption of Diablo Canyon from the safety regulations on the basis that there is an i
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cxtraordinary no, for the c1cetricity.
We lieve that there is no sound legal basis for an exemption in this case and that such an exemption, if granted, would establish a very~ dangerous precedent especially in light of'the likelihood of increased instances of such alleged extraordinary need.
Finally, we believe that the idea that modifications necessary to protect the public health and safety can be made after the plant has operated for two years is seriously mis-leading.
Full re-analysis may indicate the need to modify components which will be contaminated with radiation.
- Further, modification would remove the plant from service for an extended period.
The pressure to reduce downtime and to compromise necessary modifications would be enormous.
These substantial economic and technical problems render later modifications difficult and highly impractical.
Thank you.
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ATTACll:1ENT 1
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- <r::pany representatives and their consultants met with representatives of the AEC staff in Bethesda, Maryland on March 21, 1967 for a preliminary discussion of the criteria for aseismic design applicable to Diablo Canyon Nuclear Power Plant.
A list of thoce present at the meeting is attached.
Mr. Kelly opened the meeting by commenting that, because of our need for a construction pernit by October or Noicmber 1967 and because of the genera}
concern about carthquakes in California, ve thought an early, informal discuccion of scre of the eat thquae dwi.,n o,uest' ons voald bn Jesirable.
Mr. Tedesco of the t
staff recponded affirmatively and vent on to ask if we vere going to discuss tsuna:.i.
He said he had just read the tsunami report of Marine Advisers and was not certain
, he understood its recommendations.
Dr. Stewart Smith then proceeded to summcrize his and Dr. Eenioff's report on the selsnicity of the site and the earthquakes to be expected.
Points to which he gave particular emphasis were:
1.
In the Western United States one associates major ccrthquakes with known carthquake faults.
2.
There cre no faults in the site crea (in the sense in which the verd
" fault" is used in the Smith-Benioff report).
- 3. He ecmplete3y rules out the po cibility of relative groana displace.ent and notes that the geologists cnd seismologists agree, approaching the problem from different points of view.
4.
Aftershochs can occur in zones having a vidth of from 25 to 50 percent of the length of the main earthcuake fault. This cetimate is subject to pecsible errors in measurement. With the present state of kncvledge vc cannot always accocirte aftersho:ks with fcults. Such evidence as ve have on the 1906 San Francisco earthquake shows the afterchoch rene to be quite narrow. Ecuever, he believes that ve should use worldwide data and err on the conservative side.
- 5. The nocitram-size aftershock which cuald occur at the site vcc ecticutcd through the follovi:.g reasonsing:
There have been no corthqutkes in the United Stctes in this century cf mcAnitude greater than 6-1/2 which did not prcduce surface fnultin,,.
(Tnere are 6 er 8 de:umented ext =p)cs.
A poscible execpt.icn vculd be the 1%2 Korn Ccunty carthquake.)
Tncre are no enrthquakes of mugnitu:le creater then 6-3/h not assneicted with known fanitn. There nre no faults et the cite.
Shorefore, Dr. Cmith ernelu.ica that there er.n te no corthquake at the cito cf it.r.cnitude creater than 6-3/4.
6.
Che crea $n which the pinnt r.ite in J oentel is one of relatively 1cv scicti:Ity nn.1 hco r. Very naall curthqucJte-dn:ct,ge hintory, f6/b*$b *&
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.13 Dr. En11 asked for co=ents as ' o the use of medel vs time-history analyses for earthqankes.
Dr. Blume said either could be 'uned but that he preferred to test the design with a time-history analysis using the earthquakes postulated in his report prorated to the maximum ground acceleration.
Dr. Hall asked how many rr.acses vculd be used for the mathematical model of the containment structure.
Dr.
Blume said that they had made analyses for boiling vater reactora utilizinc 30 to ho nacses. The analysis should include major equip-ment iter.s supported on the ctructure.
Dr. Hall indicated general egreement with Dr. Blume's approach and expresced considerable interest in the application of these principles t~o the equipment and piping design.
14.
Dr. En11 asked for assurance that' the saltwater system for core cooling vill be designed as a Class I structure and was told that it will be.
Mr. Coalter of the U. S. Geologic Survey then gave his cc ments. He says he sees absolutely no problem of fault rupture and briefly deceribed the relationships of the carine-terrace deposits to the wave-cut bedrock which support this conclusion. He believec all major structures of the plant are satisfactorily-located, geologically speaking. He believes more work should be donc with respect
.. - to poscible focusing effects of the chore line on tsunami. He thinks more sggnsi-ingc chcu.1d be tc. ken offchore. He then mentioned che clide area on which the svitchyard is located, saying that he believes that we have a "vingding" of a problem to stabilice this slide. W said that cur geologict had not ir.dicated a sericas proble=, particule.rly since the ovitchyard fill vill tend to ctabilize the slide material.
(Ho'eever, later in the meeting Mr. Tedesco expresced concern over interruption of the power lines becauce of slide problena in the evitchyard.
It appears some additional vork may be needed to assure the staff on thin point.)
Mr. Marphy of the Coast and Geodetic Survey then gave his co=enta on the scismological aspectc. He said that he is " happy" with the knowlege our reports have exprecced cf the locaticus of earthquake faults tmd the acti*.-ity on them. The nppre.ch of the CorTany'c consultants is very similar to that used by the USC&,GS. He acrees that the earthquake sizes postulated are on the high side. 'Ihc nagnitudes are very acceptable. He hsc no prchien with the maximum ground acceleratienc estimated except for the figure of 0.12 g for Entthquahe "P".
. He vaald feel better'vith an esticate of 0.15 g.
}:e realicec thst it is difficult to argue abcut a differcnce of cnly 0.03 He believes that the estiented :.canimum accelerntions for the other earthquahen arc on the adequate or Cencrous side.
Mr. }brphy cornerited on the comparicon of acceleratiens with earlict reactors. He ocid that entir.stes nude for San Oncfre and I',n.libu started frca Icuo kner.eled e of the carthquuhe nituation than in evidenced in our reports and C
in ncetinCo cuch as thin cr.e.
Estin'.tco for earlier reactors had to be on the more conocrvative side becauce of luch of data.
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ATTACl! MENT 4-UNITED STATEt NUCLEAR REGULATCRY COW.ilSSIOff l
W ASHINGTON. D. C. 20$$$
i February 11,1975 3.c;;ct Nos. 50- 275 and 50-323 A. Giatbusso, Director, Divisien of Resetpx TAnoncia DI'.;LO Cl.T.'0" T "IEV The following tabic provides key dates associated vith the Diablo Canyon case:
Unit 1 Unit 2 CP Applic1 tion 1/16/67 6/28/68 CP Issued 4/23/68 12/9/70 OL Application 7/10/73 7/10/73 We and our connultants (U. S. Geological Survey and U. S. Coast and Ccodctic Survey) concurred with the applictnts' selected geolog
- cal and ccistological bases fo: design. This included an SSE of 0.4g.
We and our consultant (N. M. Nev:. ark) concurred with the appliccnts' selected critaria for scistic design, including the design spectra and datping values and the cathods to be.used for the design.
At the current tire Unit 1 construction is over 90*: complete and the fuel load date is esti=ated to be aliout November of this year.
The fuel lecd date for Unit 2 is esti sted to be about nine cenths later.
Our OL revicw is nearing co.pletion.
The SER with a few notabic
,fonics '.o.,
ur.s incued en Oet bcr 16, 1974.
Ihc princip:1 c ission uns cuc c::cest, cnt of the geel'n y and no:*scolegy f or the site. Neu infote::tirn hed beco::c availabic during the coutro. of our OL revicu jand ou. cvalunica and that of the U. S. CooJegical Survey ns ne,t lee::. pit.tc at the ti.x the SDt was 1scued. An SF.R Supplcaent was prepared for irsunnec en Jcnuary 31, 1975.
The staff had tente.tively conc 3eded that, ceamicrin; the new inf or:atien cvai?rb3 c, an SSE value cf 0.53 teuld be cppropriate for the site. L e :taff had also b;\\ UIlO,' f.,
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A. Ciambusso February 11,1975 determined that the as-built facility would be abic to withstand such an acceleration but with little or no =argin for cany elements of the design.
The staff expected that its consultant'n (U. S.
Ccological Survey) report would not conflict with its tentative conclusion on the 0.5g yalue.
The f urvey's' report was receive'd on January 23, 1975, and staff representativen cet with representatives of the Survey on January 31, 1975, to discuss the Survey's positien.
iSc significant aspect of that position is that the Survey, on the basis of nou availabic informatf an, believes that an acceleration in excess of 0.5g is nore appropriate for the Diablo Canyon site.
We have act internally on this proble: several tices in the reccut past up to the Assistant Director level. On the basis of these discussions, my opinion of the situation and steps that need to be considered is as follows:
1.
The applicant is aware of the current status and is atte=pting to acquire additional information tc alter the Servey's opinien.
It expects to,sub=1t additional information about, March 1,1975.
The assessment of that infor ction by the Survey and the staff vill result in an SER Supplement about May 1, 1975.
The ACRS bcs scheduled a two-day Subcommittec =ceting at the site for February 18 and 19.
However, the Cc=aittee vill probably not consider the Diablo Canycn application until its June eccting.
Because of the nature of the probic= and the "hard" decision that uust be made, I would anticipate a second tecting cight be necessary two months after the first cecting unicos the staff can propose a strong policy-type decision at the first eccting.
In any event, the applicatien is strongly contested and I would anticipate that the PDD will be later than the date at which Unit i vill be ready to load fuel.
2.
The current "best guess" of our geology-scistology staff is that the final Survey position ay vc11 relax from its present state (the prescat pesitien would result in na CSE value of about 0.7g) but vill not lihely result in an SSE vclue icss then about 0,Lg.
Tbc current "best guess" of our structural-ecchanical staf f is that the currcut design vill not be ahic to be deconstrated to be acccptabic for a scismic loading in c:: cess of 0.5g.
An extensive reanalysis could be undertt. hon by the applicar.t but vill probably chew that sono parts of the plant are capabic of
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, February 11, 1975 A. Giambusso withstanding various loadings in excess of 0.4g, 0.5g, 0.6g, and 0.7g, but that other vital parts vill not have such capability.
Se:c increase in capability ic possible fro design changes that might be undertaken but changes sufficient to bring the design up to a 0.6-0.7g capability arc impractical. The design reanalysis could take up to a year or two to complete.
3.
The staff 'c faced with a. horrendous backfit decision.
The decision will likely be based on both technieni and polic -
considerations. Uhile the technical considerations may be altered by additional information that may develop during the next conth or so, the degree of alteration is not capected to be signifi-Therefore, the basic problems that will exist and the basic cant.
decisions that vill need to be made are known at this time.
Those who will be involved in the polic decisions (the Co=nission cannot be involved according to T. Englehardt) should become knowledgeable with the situation as soon as practicabic.
Since the policy decisions will be influenced by the technical facts and practicalitics involved, carly involvement in the on-going technical review tay be prudent. The earliest and cost direct means of understanding the technical issues is probably through attendance at the February 18-19, 1975 Schco :ittcc cceting at the site.
The Subcon=ittee will consist of Dr. Okrent and Dr. Bush (and perhape L. Fox).
In additien, up to eight ACRS consultants vill participate. A copy of our eeting notice and the agenda for the eccting is attached. The proposed attendance by Dr. Coulter of the Geological Survey is indicative of the serioucncss of the Survey's concern in the catter.
~
4.
Consideratien eight also well be given to:
Strengthening the legal contingent acc4 gned te the. casc.
a.
In additien, a revice might bc =ade of the assigned ASL3 to assere the icvel of credentials and experience is con-sistent with the cach that is to be faced.
b.
Strcncthening the engineering staff by providing for special consultin;; advice fres groupc and individuals such ac Mcwuarh Ascociates, Franklin Institutc, Dr. J. Uct.dric, etc.
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, February 11, 1975 A. Cla=busso Establishment of a special policy a'dvisory group to aid in c.
the decision-making process. This might include individuals such as Dr. Kouts, D. Knuth, R. MinoCuc, etc.
I believe the above outlines the present situation as we in Lk'R-1 view it.
I strongly reco=cend your imediate attention to this problem.
R. C. DeYoung, Ass stant Director for Light Water Reactors Creep 1 Division of Reactor Licensing
Enclosure:
Neeting ::otice cc:
R. S. Boyd O. D. Parr Mr.' Allison T. Hirons p
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UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON. D. C. 20555 February 20, 1975 Note To:
A. Giamburso DIABLO CA' YON - SEIS!!IC ISSUES An ACRS Subcom:..ittec cceting to review the Dieblo Canyon. OL applict.tien
~
was conducted in San Luis Obispo on February 18 and 19,1975.
The Subcoenittee consisted of Dr. Okrent (Chairman) and Dr. Eush.
In addition, scvon ACRS consultants were in attendance the first day of the occting which was devoted almost in its entirety to the seismic issue.
The specific tatters discussed included geology, scistology, seismic design, seisnic testing, and seisnic scran.
On the basis of ny attendance at the nocting and side discussions with other staf f members, USGS representativer, and applicant and k'estinghouse partici-pants, I came away with the following impressions:
1.
The tuo main concerns uhich will det'cr=ine the SSE "c" value
' arc (a) the geological definition (extent) of the !!osgri f ault zone, and (b) the seicnic event that tunt be assuned to occur on the offshore fault.
I believe that the USGS geologists (lead reviewer - F. }!c!!eown) will naintcin their currently Andicated position.
The "new" information described by the applicant and to be formally documented in the near future is not likely to convince the USGS to alter its current finding.
I believe that the "new" infornation vill cenvince the USGS that the 1927 11agnitude 7.3 carthquake occurred on a transverse fault and, therefore, need not be censidered es capabic of occurring on the Hosgri fault.
I belicvc that the USGS scisnalogi::tc (J. Devine - Jead revicuc.r) would cenclude that the appropriate "g" value fer the site veuld be 0.5g if they could arsuse that the fault length ucre licited as the appli-cant contends and the 1927 evcat occurred on a trensverse inult.
lloucver, if thc fault length is deternined on the basis of the current USCC reclogical interpretation, then the sciccic event that nuct be ra r.ed by the P50S scir M erictn, in erder to bc co.atittcnt' vith the nothodo1M:y used f or the Sen Onef re 2/3 cvalt.tien, will result in a site "g" ve.luu ninilar to that dnteruined for the San Onnf.e sito (0.67,).
It is my opinion t
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that, unicss specific guidance appropriate to this unique situation is provided to the USGS Ecologists and scistolegists, they vill proceed with their review basing it upon their standard methods and arrive at a site SSE "E" value vc11 in excess of the 0.4g value approved for the CP and used for the design of the almost coepicted plant.
2.
The as-built plcnt has significant margins in its design and it ic capabic cf resftting refr.mic load = well 2n execss of those associated with the 0 4g reirmic event assumed for design.
The staff is prcscntly convinced that tha design is " good" for a 0.5r,.cvent.
!!ovever, to convince the ACRS and others of this vill require 3-6 months of cpplicant and staff effort.
If an l
event in the ath" # 0 Ac -ec.d_be ce;:tidere.4 it will be possibic to show that many parts of the plant can safely resist such loads; however, many parts vill need to be modified and very likely for sene of thesc the modifications vill not be practical.
1 The evaluations to accomplish such a task, with the rigor that j
vill be required, vill catail years of applicant and staff ef fort.
t 3.
The " tone" of the questions and comments from the ACRS Subconx.ittec i
i mcnbero and th~c consultants indicated to me that they vo'ld find u
a 0.5g value acceptabic and could be cenvinced that the as-built plant could adequately resist the increased loads associated i
with the event.
However, they are not lihcly to be convinced I
unicas a rather complete analysis is perforned for a 0.5g event and the ure-of our cdtrently approved seicnic design criteria.
To dato no such analysis in availabic; the present positiens i
of the applicant and the stnif as to the ability of the plant to adequately resist a 0.5c event are bared on qualitative assesnuants supported by a few typical calculations.
)
In sur ary, es a rer. ult of devcicpnents during the pcst voek. I continue to believe that, unicsr specific guidance, cepport and directicn is i
providcd pr,orptly by the upper ennecenent icvels et MRC and USOS to the " working" Icvels in the tvo c'rr.ani:ntion, pesitions that do not 1
i nececsarily ref3ccr the judn=ent of upper-level canctercut will be f os uelated and doce.scr.ted to the extent that later codification will j
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3-February 20, 1975 A. Ciambusso be difficult.
Harold Denten and his people intended to have further discussions with their USGS counterpsrts during the evening of February 18 and perhaps on February 19.
I suggest that upon his return, RL and TR coet at the appropriate level to discuss this critical situation and agree on a course of action to be followed.-
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ATTACll!!ENT 6 UNITED STAtts NUCLE AR REGULATORY CO.W.115SION W ASHINGTON. D C. 20$$5
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Docket Nos. 50-275 and 50-323 Roger Boyd, Acting Director, Division of' Reactor Licensing DIALLO CAh* YON L'c stron;1y rec =~.end !! at is=edicte etings te held j
with upper c.r. age ent to initiate actier.s te proepely dcvelop a firm basis for er. king a decision on Diablo Canyon. Our preliminary thoughts are provided in the enclosure.
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l R. C. DeYou c', Assistant Director for Light s'. iter Reactors Group 1 Division of Reactor Licensing t
Enclosure:
Diablo Canyon Coology-Scismology cc w/cnclocurc:
R. licine=an T. Schroeder
!!. Denton R. llofmnn C..Stepp 0,. Parr
, vtT. Allison 9
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DIABLO CANYON GEOLOGY-SEISM 0 LOGY 1.
CEOLOGY-SEISMOLOGY SITUATION l
Based on USGS draft report, Renner Hofmann's assessments to date, as discussed with Dennis Allison, and the meeting of December 30, 1975, betvcen the staff and USGS, we understand the geology-scismology i
situation is as follows:
is 1.
USGS believes that the 1927 cvent might have occurre'd on the Hosgri Fault so we should place a cagnitude 7.0 to 7.5 carth-quake on that fault. The published magnitudes for the 1927 event are in that range.
This would Icad to a calculated peak g
accelcration much higher than 0.5g using standard nothods.
The U3CS position is suspect. Renner Hoftsan of the staff has reviewed the felt effects of the 1927 event and they sccs to be very good data.
In all respects they dc=onstrate that the i
1927 event was either cuch farther out to sea or was n.uch smaller.- Either way, the plant, which is adequately designed for 0.5g using standard techniques, could cche the offects of 4
this earthquake when it is moved in an appropriate car.ncr.
WedonothaveadirectverificationofthemAgnitudedeter:ination at this time. Renner Hof= ann has reviewed the locatien data, which indicate that the 1927 cvent was or could be on the Hoscri
(
Fault, and considers them to be of very poor quality, capabic l
only of deter:1 sing the location to be secevhere off the coast of Centra) California.
l The USGS exprccced a villincncsc to take another look at this l
acpcet of the geological situation taking into account Eenner i
i Hofcann'c and Carl Secpp'c co:ntnts nado at the meeting on
}
Decceber 30, 1975.
.l 2.
The USCS believes that the Harcri Fault is core than'90 tilcs j
long and nny even be esupled with the San Si:cen Tault at the i
northern end of the Hongri'Tcult.
This it a concubat incen rucun i
statettent because it appearn that one mus t add thu f an Sit:en fault length to the Hoacri Fault on the north, an vc11 nr a feu miles en the south, in otdar to r,ct a 90-rJ1c lencth.
Ucycrthe-Icca, what we bc11cvc they are saying is that other interpretatient l
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2 than the applicant's can be placed on the ccological evidence
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of fault Icagth. Furthermore, with these other interpreta: ions.
the fault icngth'is unknown, except that it is greater than 90 miles.
It is not at all cicar where wa are going here. This is a question vc cust / 11 vith even if,USGS is convinced of our position with rerpect to itca 1 above. Unfortunately, we do not have a speciff e earthquake recocnondation fro: USGS based on fault length to 6
A deal with.
Renner Hofc-nu is looking at the seismic profiles but the USGS opinion (that another interpretation is possible) will prcbably Perhapa the fault length could be limited to 90
, hold water.
A fault length miles or a little mora with additional fic1d work.
of up to 120 miles would give a 0.5g peak acceleration, assu=ing mostly strike slip motion and a, rupture length of one half the We feel that thoxc are reasonabic assu=ptions for fault icngth.
this site, but the USGS may well disagrec.
USGS believes that the standard cathods of cniculating a peak i
3.
acccleration and scaling a spectrum to it are not appropriate
- hile they do not know what this close to large carthquakes.
a would be appropriate, they cicarly invite us to find a batter vay.
Renner Hof= ann is working on two approaches which can shed scuo light on the cubject and may indicate that the plant could take a large carthquake on the Ucrcri Fault.
One appreach is to place the c.agnitude 6.3 San Francisco carthquako on the Hosgri Pault and uce the felt effecte to estieste the peak accelcratiens.
The second involvec calculations of peak acccioratien based on
.i four miles of the fact that culy the energy released in about fault length will contribute to the pcah neccleratica at a This type of renconing distance of four n'ics frou the' fault.
could perribly provide a rationale for recenciltug tha differences of opinion wit.h which we are dealing.
The quality of'the USGS recor.sendation, fr. for en wo een tell 4.
at thi,q_ti-e, is poor.
t Their rpecific rocc==endation to plaen a magnitude 7.0 to 7.5 a.
carthquain un the Ucciri Tao.t jn bao.d on an idea which we i
connider not valid.
Uor ect, U!:CS h is agreed t o consider l
thin cattet further in lit.hr of our cere.cnts to then.
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Their reco=mcudation decs not deal with a magnitude based on f cult length, which =uct be dealt with.
Indeed, they do not say that item a above is a worst case or design case, but.ncither do they say that there might be a worse case. We need scmething better than this to work with.
c.
It seems that we are dealing with the opinion of one to four pi.opic and we are tot sure which ones.
For exw pic, one of these persons (Holly Wagner) is highly respected but we do not even know what he thinks, cuch less what a con < casus of top geologists would be. As another exc=pic, llanks, a Cal Tcch professor and part-ti e USGS c=picyce, published en article secting that the 1927 earthquake was not on the Hosari Fault, but we have no indication of whether or not this was given any weight.
This is not an, adequate a
base for a decision as i=portant es this and is, in our
- opinion, e boat USGS can give ur.
d.
llolly Vagner is the highly respected geologist making the geological interpretations, yet we have been unabic to discuss the tatter with him. All we have gotten is second-hand word that good poopic have reviewed it and this is wht.t they said, without ccaningful discussion of the tech-I nical renconc.
RECONC'*DATION AT Tl!IS TI2C' II.
Clearly we can bencfit free. further discus'sient with U,CS at a 1cuer 9
level boiore they send their fornal rocc.:=endatien. However, in light of the scricus nature of the decision we cust t.sho, the vnhnown quality of the USCS reco:cendation and the extra difficulty involved in reversing a USGS cpinion after 3: is publinht d, we rect.r.::end contacting tep canagocent at the Department of In crier and c:: pressing our need for an immedint c, accelerated rcevalu.u icn of the gcciogic cituation, includingt 1.
The independent opinions of coveral top USGS geologiuto not horcto-fora directly involved in the Diablo Ct.nycn review.
2.
A c1cht M:precaf en of tho technical rcanoning which can be dio-cueced uccnicch.11y with the ataf f.
In additica, wo shou 3d nus.diately retain 4.dditional top scolegiate directly r.n consultcr.tu and init$ ate further inhpendent revicw on our ovn.
Depending en uh%h how quickly vc take acticn, the reoults.
cuy or t.sy not be c.copicted in t.h to suppert the cchedalc for licennini;.
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I III. POSSIBLE FUTUP.! OPTIONS If we receive the USGS rece =endation as it statuls now, we will have three basic options, assining that we vill publish the SER Supple =ent and take a position instead of asking further questions and slipping the schedule. The three basic options are:
1.
Oppose the operating licence. Leave the door open for further study, etc. Describe why.
t' We have a p6or basis fer this action at this time, other thr.n
' general conservati,m and "PG*u hasn' t donc enough to make every-one htppy." Such crbitrary cet.scrvatics vculd not be an adequate
- basis in this case because of the largo financial loss involved and the severe inpact such action would havu on the nucicar
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indus try.
2.
Favor the op' crating license.
P.cquire further study, etc. Describe why.
If this 1s donc en the bacic of rejecting the USGS rece:-
~
a.
I mend;u.icn because it is poor, there would be difficulty justifying the action.
k b.
Alternately, vc could peccibly accept the USGS advice and justify the action on the basis of probabilitics of earth-quakes and structural and :-echanical d;.=sco (treating it an execpticu to Appendix A to Part 100). This would a t.probably be coupled with requirc cute for plastic structural analysis, backfit, furthet gcolo;;ical study, etc., within specified time pericds. There would be s,cco difficulty in justifying this approach also.
-c.
r Deceribe the I
3.
b*cither oppose ner favor the operating licenne.
situation.
Although the Aci$, lleuring I':.ard, Cc= ienien, and courte vill 5
probckly all have to decida thic carc cny.'..y, it is not satire-factor /,ter us to go to th w vithout a re w.*:endation.
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/ /2 yg PROCPN! TO ESTASLISu EASIS TO LICENSE DI AP).O C.U' YON BACKCP.0USD.V D PROPOSED PROCPMI Constructicn permits were issued for Diablo Canyen 1 6 2 in April 1968 and Decenber 1970, respectively.
L'nic 1 is nearly co::pleted; Unit 2 is a year or co behir.d. The SSE for the site was set by Dr. Ucu ark,
'lhe value select ed the USCS, and the U. S. Coast & Coodetic Survey.
The OL was 0.43 and th_ plant haa lcen crnetructed to that value.
O.r revicu applications for both units were decketed in October 1973.
tirre we recognized vas essentially cor.pleted by Jr.nuary 1975; ce that Tne that on the basis of neu evidence the SS vould be increened.
staff believed that the l'SCS uculd cencur with a site "g" value of 0.5g and uc had done sufficient vork to convince us that the pl a:
could scfely withstand ruth an carthquake. On January 23, 1975, we were suiprised by a tTCS report that concluded that an cecclerstien of 0.5g uns in its epinion inadequate for the site on the basis of present inforr.ation.
At that time DPJ. reco:cended that two approaches be taken to resolvc the 1,cuc.
First, continue to acquire additicaci infor e.tfea to convince the USGS of the adequecy of a 0.5r SSE.
Sceondly, ascu u the revicuar 1cvel, would renain ndamant and seek oth:r the l'SCS, c.t to confirm or nodify its findir;.
'lhe decirion une made to rie n n e.
pursue only the first approcch. Today, uc are cr.sentin11y where uc verc laut Jcnuary except thc: the plant is alrost ready for fuc.1 loadir.g.
Once oscin we are faced uith develeping a pro pan to establir.h a bacis to post.it a decisien to be made on t':e licensint of Diablo Canyon. Uc believe it uould be ir prudert a once cccin purcue a sinnlo path b:.ced on ace,uiring. additional it.'letr.atien to cor.vince th( l'sCS review tcan (a relctively fee individuals) to r.wdify its current pesition. Uc a:ain r2cor-end a raulti-faceted '
approcch.
The progrcn vc would prcpece to pursue is nr follevst Foren11y request that ca independcat rcvicu be cor. ducted within 1.
USGS Le t.oi. fir. or codify the current l'.75 revice to r. findir.r..
This rcquent night be ec.de by Chaitr.an /.ndcra to the Secretary of the Interior c.nd could, if Iccal connderationn demand, be based on pr.oric L'act. Ceaut c.,ncer:.e rcther than the Dit.blo Ccnyca inue.ticac.
' Concurrently, fern a teat.'of contmitar.tn connintinr. of c:n of 2.
natien:1 r.Lature in the fic1h of p :le y, rei:ecolegy, and i
r,e icn i c d e f.n t o e va hn t e t h e s i t u a t i or..
This tcan nicht put:u veri (un raths, inclu?ints I
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Assume a " great" earthquake could occur as the USGS review a.
implies and derenstrate by logic, evidence, and judgment that the ggerty transfer to the cite
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within the ccaten cannbi
- es of the nu-$r*.p'---_
b.
An independent evaluation of the evidence'to arrive at a conclusion en the SSE that nigh~t be corpared to those of the USGS review team and the pan'c4 of experts cctablished by the licenr.ee.
c.
Assess the prospect for upgrading the plant _ design to hir,her SSC values by plastic analysis and/or ctructural codifi-catiens end terting.
3.
Concurrently, form a tcsk force to revice the current statue in an atletpt to determine if a probabilirtfe baris ccn be estch-lished to license Unit I f or en interin peraca et operatica While the other reviews are being conducted.
Concurrently, infore th$ licensee of the course of action ce 4.
are pursuing and require him to pursus similar and/or citernative courses so that our final decisions nay be r.aJe on the basis of our evaluation of his efforts supplemented by our independent assesenents.
11ST.n1 ATC ACTIC:t We are planning to take in.cdiato actions to initicto so c of the approaches indicated above.
Specifically we plea tot 1.
Moct uitb ':?? ne w -
nbigin aperov.C r t *u ~~eral v
- e approach or to obty);
- n; p atti r ~. 'fg r e g ra3_
2.
}!cet tonorrou (at Chientc,*,1111nois) with 4-. :tecark to begin to fornulate thq team of ennneitante diteurYinen 2 above, and the tank force discuotd in ice.2 J n@.CXt thC t.tua noctint,Dr. !!cenath vill naLe e presentatien to us so that vc nay c)carly understcnd the baccs and linitat.!cns of his rccer.t paper on seismic decir.n margina and probabilitieu of stru:tural and mechenleal failurec.
~
3.
?! cot here, later this week, with the licenaec to advise him of the current status of revi(w and of the pregrsh Vo inLcnd to purouc to establich a Lavic fcr a decision.
In v1 W of the sericuaness of the problet, it in essential thu strong Ry.ulat oty menrenent be k;'cret kr.cciately to "tc:na;,c" the tcan of coacultantr. and thn pr..bebf if ty tash forcu.
There re;nacc:- rhvald be the hir.he'rt level uc.aascra that oc eno practically ar,cign to the t n:.Lt..
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_ASSOCI ATED C0!:STDER*.TIO! C In developing a progran to follow to resolve the Diablo Canyon prob'let, consideratien should be given to:
1.
The inps.ct of our decisiens on the nation's crcrgy problens and progrens.
The irpact of potentdal denial for operatioa of a plant approved for construction cannot be underestinated, especially where the barir. for denial is in controversy.
4.
The ir. pact of our decisicas on the noratoriun before the California voters.
S.
The inpact of our decisions on the viobility of continued operation of plants at other sites with altered scisnalogical bares, such as San Onofre, Pilgrf:.1, etc.
4.
The itipact of our decisions on the viab!!ity of continued operation of plants where it is uncertain that the c pability c.vists to withstand altered, design bcses in arcas other than scipnic design, such as ccatainnent structural desica, pipe whip inside contain-cent, spurious valve failures, etc.
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DISTP.1T.UT10;;
li. Rusche E. Case P.. lieinernn R. Haccary I. Sihueil K. Kapur
!!. Denton U. Cr.: J.1.1 C. Stepp R. llofnann J. Tourtellotte R. Boyd R. DcYoua<J M Allison e
e G
S 9
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Existence of Hosgri Fault reported in scientific literature--Hoskin and Griffith's article.
January 1971' l
l Regulatory staff to counter I
intervenor's contention that sei.?cic hazard should be reviewed, advises Hearing
~N Board at NEPA prehearing conference for Diablo Canyon that there is no new information on earthquake hazard.
June 1973 Regulatory staff receives reference to Hoskin's and Griffith's article and requests additional information from PG&E.
August 1973 Application for Operating License docketed - Units 1& 2.
October 1973 USGS begins offshore surveys.
December 1973 s
PG&E begins additional investigations at s taff request. December 1973 ASLB considers and rejects request to issue stop-work order.
Staff opposes order. April 1974 6
~
e.
USGS publishes a preliminary report concluding the Hosgri to be an active fault at least 90 miles long, therefere capable of sustaining an event greater than the SSE for Diablo Canyon.
August 1974 ASLB considers and rejec,ts intervenor's second request to issue stop-vork order.
Staff opposes order.
November 1974 g
Regulatory staff receives USGS conclusions:
1.
1927 earthquake may have occurred on Hosgri fault - magnitude 7.0-7.5 (Richter).
2.
Hosgri fault more than 90 miles long.
3.
Standard methods for calculating peak accelerations for fault this large and close to site are likely to lead to underdesigned plant.
December 1974 Upper level management at NRC
'l reports to be unconvinced of merits of USGS findings.
January 1975 Staff Supplement #1 to Safety Evaluation Report issued revising upward the Safe Shutdown Earthquake for Diablo Canyon.
Staff further concludes that although plant designed to an carthquake resulting in 0.49 at the sit.e, the "as built" facility.
could eithstand the highest acceleration--0.5 --associated 9
with the larger Safe Shutdown Earthquake.
January 1975 Staff meets with USGS who have revised initial estimates upward and are advocating an SSE value of 0.79 February 1975 Staff recognizes that U7GS position will require design reanalysis, taking up to two
/'s years and perhaps more.
Staff further concludes "[S]ome increases in capability is possible from design changes that might be undertaken, but changes sufficient to bring the design up to a 0.6g-0.79 capability are impracticable.
February 1975 ACPS Subcommittee meeting on Diablo Canyon operating license.
Meeting explores problems of seinmic design and the Hosgri fault.
February 1975 From position taken at ACRS meeting, the upper level management recognizas that "unless specific gu*o'nce is provided to the USGS geologists and seismologists, they will proceed with their review basing it upon their standard methods and arrive at a site SSE "g" value well in excess of the 0.4g value approved for the CP and used for the design of the almost m
completed plant."
- Further, the same manager concludes that "unless specific guidance, support and direction is provided promptly by the upper management levels at NPC and USGS to the " working" levels in the two organizations, positions 4
~
that do not necessarily reflect the judgment of upper-level management will be formulated and documented to the extent that 7
later modification will be difficult.
February 1975 Construction on Units 1 and 2.
have continued unabated.
Unit 1 due to be r'ady for fuel e
loading uithin 6 months; Unit 2, about 1 year from then.
February 1975 ACRS subcommittee meeting on Diablo Canyon which considers Diablo Canyon scismic problems.
May 1975 Regulatory staff puts together a team of consultants to demonstrate that, assuming occurence on the Hosgri fault of an carthquake as large as the USGS review implys (7.5), the energy transfer to the site would be limited to within the design capabilities of the nuclear plant.
Concurrently, the staff initiates a rcview to determine if a probabilistic basis can be established to license Unit 1 for an interim period of
. operation while the reviews are being conducted.
I,dditionally
~
the Staff informs PG&E to conduct a similar analysis.
In developing this program the Staff considers the following:
1.
"The impact of our decisions on the nation's energy problems and pro, ams.
The impact of potential denial for operation of a plant approved for construction cannot be underestimated, especially where the basis for denial is in controversy."
2.
"The impact of our decisions on the moratorium before the California voters."
3.
"The impact of our decisions on the viability of continued operation of plants at other sites with altered seismo-logical bases, such as San Onofre, Pilgrim, etc."
4.
"The impact of our decisions on.the viability of continued operation of plants where it
-g' is uncertain that the capability exists to withstand altered design bases in areas other than seismic design, such as containment structural design, pipe whip inside containment, spurious valve failures, etc."
January 1976
ACRS subcommittee meeting.
Staff and PG&E begin presen-tation of views on adequacy
~
of scismic design of Diablo Canyon.
May 21, 1976
~
ACRS subcommittee meeting.
Staff and PG&E continue presentation of views on adequacy of seismic design of Diablo Canyon.
June.1976 ACRS subcommittee meeting.
ACRS consultants present critique of staff and PG&E presentation.
Generally the consultants conclude:
1)
The design response spectre adopted by the Regulatory Staff falls short by as much as 50%
in depicting the 7.5 magnitude earthquake selected by USGS as the Safe Shutdown Earthquake.
2)
The conclusions are based on poorly justified modifications.
The process
s "makes a mockery of the seismic analyses and sets a dangerous precedent."
October 1976 PG&E begins reanalysis of plant design consistent with new criteria set by Staff.
January 1977 Staff invites PG&E'to make f
application for an interim operating license based on pw
. demonstrating (1) the low probability of an earthquake resulting in radioactive release at Diablo Canyon; j
(2) a commitment to make necessary changes; (3) an j
evaluation of the practicality of making needed changes to a plant that has gone critical.
March 1977 Unit 1 estimated to be l
physically complete by
'N April or May; Unit 2, by December 1977 March 1977-ACRS meeting scheduled June 1977 g
9 e
f
.