__ __ . . . . - - . . . ..

' Copy No. out o f Five (5) y***

copies fo. warded to T.he- "

[dPhilippine Covernment, oy'

the IAEA. 4'.

t *t

ii V. .

IP 'l i n N y gg......ch;5-:.a... .d: ,,ists cfSc_page= gg

.

A ;

..o._ 1._ of i0;i3S SGri38

gi

n..11

II'*

!.!.Ift. --

FHILIPPINE NUCLEAR POWER PLANT e, _

O i/f

'

UNIT NO. 1

Declassified By 1

J.R{>Shea,DiR,1P,NRC~~

Ref. 5. tate 9/17/79 memoREPORT =

hOF 6

THE I. A.E. A. SAFETY MISSION9$

EON

GEOLOGICAL HA7JRDS & GECTECHNIC AL ASPECTS- Wg,

'

..

, c-

' EEE,

_

w.-

, _.

v..

-

*fn

1284 )42 -- be-Philippines-

y.ay 1978. &''-

t W-

July 1978 - Vienna t e-'

b| 7 6ilO rO~ d''* gygr,.

/-Cbss:fied .y ye..

~,,~.oc~ ~ ~ '

~

. .__

C00'.7?Cif9_

--- - 5- - S s- L

~~

J Re':.:.: . _. . == en;1_ _ _ .

--~~--L __ ^*"* *-- - - - - --- -- _ . - . _ . , . . . . .-

' ' ' ' "zg.. .a .-_ . _ _

's;. . _ . . . . N. . ,_, ... -

..... __ --a

*5__

~ ~ ~ ~

7911010 g y - - ;

Y

k!-1-

. g.- -

.

EP?EAP3LE W

At the request of the Philippine Atomic Energy Coc=icsion (PAIC) ]iacting for and on behalf af the Governcent of the Philippines, the

International Atomic Energy Agency (IAEA) provided the advisory services |?eof 2 dafety Mission for a review of certain geologic.1 and geotechnical

~ it

aspects of the site and its environment for the Philippine Nuclear Power ,

Plant !!o.1 (P!TPP-1). The Mission visited the Philippines from 1 to 9 g't

May 1971 and =st in Vienna from 3 to 7 July 1978..

The Director General of the IAEA would like to place on record his :'

'

understandng that, upon ecmpletion of its work, the Mission has for=ulated-

such recoc=endat e:ns as the Mission, to the best of it s judge =ent , considersdesirable for the attention of the Philippine authorities with respect tothe ceasures that should be taken for ensuring tne safety of the plant, the 4

_

plant personnel and the public. The Mission wishes, however, to point outthat only a s=all part of the safety aspec.s were considered by it , and thatsuch ccncideration was limit ed to geological and geot echnical matt er=.

It should be noted that the Mission's conclusions and recommendationscet out in this report t

,

(a) are based on the documentation and inforcation made available to,

it by the Philippine authoritles and are =ade on the ' Mission's-

collective expertise without endaging the individual responsibility -

.of any of its members or the Missien's liability whatsoever 1

(b) do not engage the IAEA in any way ner imply any guaran:y or legalresponsibility on the part of the IAEA. .

'

In view of the nature of the info:=ation contained in this report , it sdist ribution is strictly restricted and subject to the discretion of the

-

.

Philippine au:horities. -,

*

.

1284 143 ya

.

b

U'

,,

b3 )s.s4

J

__ __ _ _ __ _ __ _

. ,.-* **,..

' F"3

is

.h- ii -,

atTABLE OF Coh7E:.'TS

.

RE%GLE,

'

IlfrRODUCTION|'

3ACKGROUND -|*

SCOPE OF REVEd.

VI3RATORY CROUND MOTION AND SURFACE FAULTINO

VOLOANISM-

CE0 TECHNICS

CONCLUSION-

ANNEX 1 List of participants durf-g the visit to the Philippines~

UCGX 2 Itinerary

ANNTX 3 List of additional documents presen*.ed for the meeting in Vienna3 - 7 July 1978

*ANNEX 4 List of experts who attended the meeting in Vienna ,

l .

-

.

'~

1284 944

E

.

.bmimu,W>-MEink-

. ..

bi-r

I.' '

.- , ,

&

- ii - [- re

h~

TABLE OF CO!.7E!.TS

4

PREAM3LE|

I!iTRODUCTION

9BACKCROUND *

*

SCOPE OF REVIEW j;'.

VI3RATORh CROUND MOTION AND SURFACE FAULTING

\DLCANISM

CEOTECHNICS

CONCLUSION *

,

ANNEX 1 List of participants during the visit to the Philippines

ANNEX 2 It inerary

ANNEX 3 List of additional docu:,ents presented for the meeting in Vienna

3 - 7 July 1978)

A!CEX 4 List of experts aho attended the neeting in Vienns,

.

-..

1284 145. .

.

O

e

t

c y..

-

6

, m

Ps- 4

:

. - . . . st.

. __. . _ _ _ _ _. . . _ _ . . _ . _ . . _ _ .

:. .

-

[

!

-1- |t

IN?RODUCTION ,

,

-

The IAEA safety mission composed of the following experts: -

rSwit ze rland ;MM. W. Harsch -

!It alyF. Muzzi - ,

hUnited States of AmericaP. Rizzo -

+

J. McCullen, IAEA staff member gJ- @E. Iansiti, IAIA staff member

; i,-

visited the Philippines during the period 1 - 9 May 1978 sad had discussions hhwith the experts and repnsentatives of t' e Philippine Atomic Energy Commission bn

(PAEC), Nuclear Pewer Corporation (NPC) and Westinghouse. A list of the hpersons met during this period is enclosed as Anne i and the itinerary is

Tpresent ed in Annex 2. During this visit , it was not possible to have discussion a

*P

with the experts who have prepared the Preliminary Safety Analysis Report r k

(PSAR) and performed the seismic analysi's. At the request of the Covernment fof the Philippines the Mission was reconv*ned wit'a the same participants with f[the exception of Mr. McCullen who was ill at this time, in Vienna from 3 - 7 {July, 1978. t

1||:

The members of the Mission received during and lafore the meetira a y,

substantial amount ( f additional materials whose list la enclosed as Annex 3 $.; -

On 3 July, the experts of the Mission discussed the additional mate rial with [,

Ithe experts of PAIC, Mr. Ibe, Mr. Santos and Mr. Willis (IAEA Technical'Assistance expert )..

..

In the following days, from 4 to 6 July, the subject was discussed ',

under the chair =ansh!n of Mr. Ibe with expert s from PAEC, NPC, Ebasco, {,

Westinghouse as well as independent exper:s (see Annex d) invited byEbasco and NPC. Mr. M. Ros en and Mr. A. Karbassioun, st aff = embers of the -

' Agency, and Mr. C. Willis t ook part also in the discussion. A list of all bparticipants in the meetings is enclosed as Annex 4.

The peesent repo rt was prepared by :he Mission and includes discussion -

>-and recommendations on specific technical items on geological hazards andI'igeotechnics as finalized during both periods. It supersedes the preliminary

draft repor: prepared at the end of the visit in the Philippines in May 1978and it represent s the best assessment possible of the situation within the

1tmited time available to the Mission. $

1284 046 F

m.

-.

+.

k*,

=r-me.

'

>+.-2--

5ACCRC'JN D

The PNPP-1 is locat ed at Napot Point , Bataan peninsular. A reorgani:stionhas taken place in the Philippines since the previous safety review =ade bythe P.A.E.C. with an IAEA Safety Mission during 5 - 22 July,1977 New the

De part =ent of Energy has overall responsibility for the nuclear programmes, itoand both the P. A.E.C. and the N.P.C. are in this Lepartment.l!

The P. A.E.C. is the compet ent national authority responsible for i'

licensing and regulating nuclear projects including PNPP-1. All regulatory,,

activities are the responcibility of the . Nuclear Regulation and SafeguardsDepart ment (NRSD). The N.P.C. is the utility company directly responsiblethrough its Special Project s Croup - for the PNPP-1.

,

PHPP-1 is a turnkey project with Westinghouse International ProjectCorporation serving as the general cont ractor; =ajor sub-cont ractors include

,

Burns & Roe as architect / engineer and Chicago Bridge & Iron as containmentvessel supplier. E3ASCO serves as general consultant to NPC as well as for

directing the sit e work and providing relat ed part s of the PSAR..

ACENOWLEDGE'E.NT

'he M'ission wishes to express its thanks to the P.A.E.C. and the Philippine~

Ecbacsy for their kind hospitality and support during the Missio~n's stay in the

Philippines and the =eeting held in Vienna. Further= ors, the Mission expressesits thanka to N.P.C. who made a room and secretarial services available in itsdowntcwn office in Manila. Finally, the Mission wishes to acknowledge the

kindness of both Westinghouse and their local cont racters P.C.I. who made

available two helicopters for visiting the sit e and its surroundings..

!, SCOPE CP TIC RE 7IEW

The Mission visit ed the site and observed const ruction activities and ,,

local site conditions in May 1978. During the course of the visit in the-,

Philippines and meeting in Vienna, the experts held meetings and discussa.cna i ,

(.with P.A.E.C., N.P.C, Westinghouse and Ebasco (the latt er was present fordiscuss:.on in Vienna only), reviewed and studied material provided by the '

applican; in the PSAR as well as the Supplementary Mr.erial provided by^

,

t

P.A.E.C., Ebasco and Westinghouse and PNPC dealing with vibratory ground .

e-r

P00RORGNAL i- ~ ~ ~

' " "- .

. . _ . .

.

3_,

: tion, geological hazards including surface faulting and volcanism, 6

i'

foundat ion engineerin; and seismic analysic. At the conclusion of the g

visit to the Philippines and of the meetings in Vienna, this report t'

was prepared which includes ce= ents en the safety of the site from the [;oint of view of geological hazards and foundation engineering. y

- mIIr

VIERATORY CROUND POTION A!!D SURFACE FAULTIl!G g4

The . review of related sections of'the PSAR and of the additional data t a

rrcombined with the discussions held in July 1978 indicates that a comprehensive 9series of investigations hate been conducted towards establishing suitable y

seismic design bases and considering the need to design for surface faulting. Iis

The techniques and =ethods used in the investigation are generally regardedas st at e-o f-t he-art and consist ent with those used in the United States, 4

4Europe and elsewhere. However, several conceptual / interpretational issues a

have developed during our review process which might impact on the design of F1

the plant. These issues are enumerated as follows: ;*,

(1) The approach and judge =ent used to postula n the =axamus earthquakes [[for deter =ining the level of the safe Shutdawn Earthquake (SSI). In

addition, we have concern with the approach used in considering the }'

seismic risk associat ed with the eastward deccending subducting slab i;

beneath Luzon. ' , . ''

LS

(2) the conoideration of a relatively shallow, ficating earthquake inl ,,*

the i= ediate vicinity of the sit e. pt'

(3) The consideration of a postulat ed earthquake on a possible shore- IPtr

parallel fault approxi=at ely 15 - 20 km offshore the sit e. rr

(4) The lack of adequat a consideration of a possible there-normal fault [t-

on the south side of the Napot Point Peninsula. p-

ksEach of these issues is more fully discussed in the following paragraphs.

p.

V

Cbk b &POSTULATED MAXIrJM EARTEUAKESP.

Each of the postulated maxi ==.s earthquakes listed en Table 2 5 2-4 of the I

IPSAR is associated with a known capable fault in the vicinity of the site. The jsagnitucte of the =axi. us event , which is postulat ed to occur at the fault 's |

'

closest approa:h to the sit e, has been dct er=ined by the Applicant on the

?00R BRGIN3 i- -- -~ ,.

_. - _ _ . _ _ _

t'

6-

I'

i.- ,

. -.

r r-acsu=ptien of 407. of the fault 's total loncth of rupture durirs the

,

'post ulat ed e vent .

Our review of the dato presented in the PSAR as well as discussions in'July 1978 coupled with data available for faults elsewhere in the world

indicate that certain of the postulated maximum earthquakes should be coreconservat ively int erpret ed. Firstly, we judge that a magnitude 7 5 t o 7.8 -

event can be reasonably postulated to occur on the San Antonio Fracture

Zone. 2econdly, in accordance with the st ructural =odel provided in Chap.2 51 the Mission judges that an event having a magnitude in the range of8 can be reascnably postulated to occur directly on top of the subductingslab at its closest approach to the site,at a depth of about 50 - 70 km.

This is opposed to the magnitude 7 9 event postulat ed by the Applicant to

occur at a distance 100 km west of the site. Thirdly, we judge the data =

to show that an event having a =agnitudo in the range of 7 5 could be reason-

ably postulat ed to occur in the Manila Bay Fracture ZorA

It appears from the above considerations coupled with the Applicant 'sother postulated =azimum events that the event postulated to occur beneaththe sit e on the subducting slab might control the seismic design basis forthe plant . There are very little data available to the profession for

'

assignird a "g" Value, est ablishing a complete seismic design basis or for M'

evaluating oth'er ground motion effects for this type of near-field event.Conventional att enuation relationshipe, such as used by the Applicant for

- the other =ax1=*.:.s event s, =ay not be applicable for such a model. Rat he r,so=a type of scaling approach would appear : ore appropriate. Consequently, '

detailed additional work should be direct ed toward evaluating the above gpostulat ed event on the descending slab from the Manila t rench as well as kthe other postulated events described below.

w-

1284 349 -SHALLCW FicATING EARTMCUAKF.; $

The Applicant considers a " floating" earthquake of agnitude 4 5 without-adequat e subst ant iat ion. The tectonic model developed by the Applicant doesnot adequat ely define the t ectonic st ructure i==ediately east of the Manila -

Trench, specifically the zone designat ed by the Applicant as the west LuzonTrough. ' Consequently, the Mission is not able to agree with the Applicant 's

.assignment of events having a magnitudo greater than 4 5 to this feature. e>

300RORSNAl. 1.-

e

..

_5-

Marcover the Mi:sion was unable to fully assess the pocsibility of a highercagnitude shallow event occurring beneath the site because of the lack of

a co=plete composite epicenter map and a composite earthquake catalegue.

The Mission suggests two possible alternative approaches to resolvirgthis quection at this point in ti=e. Firstly, a = ore thorough and detailed

,

analysis of all available earthquake data could be performed. Secondly, *

|those events within all bounds of the Central Lucon Tectonic Province shownon Figure,2 51-27 which cannot be clearly assigned to the Manila Trench, the

!San Antonio Fracture Zone, Manila 3ay Fracture Zene, the Taal Frac.ure Zone,,

the Philippine Fault of the Iba Fracture Zone should be treated as random and !

assigned to the province, and be postulat,ed to occur beneath the site. The I

Mission has particular concern for at least three particular events listed jas follows: *

Ihte Lat . Leng Mse. Dept h -

.iJune 6,1933 N14 E 120 6.25 Unknown i

Nov. 26,1934 N14 E 120 6.25 Unknown

Aug. 31,1960 N13 8 E 119 9 4 75 24 k:s|,

In developing the composite map and composite catalegue, the Applicantmay encounter other events not observed by the Mission. In any case the Mission i

reco== ends a, searching of the actual recordings with a view toward relocatingthe above events as well as other events with unclear or suspect published )

.locations with a higher degree of accuracy than heretofore available. Thiswill allow for a high level of confidence in the assign =ent of these eventa

}to a st t-ac.ure or to the province. L'

|-As an alternative approach to the question, the Applicant could postulato f

a randos event having a magnitude in the range of 6.0 and a challow depth I.

-(less than 30 k-) to occur directly beneath the site. In considering such iIan event the Applicant should develop st rong technical basis for his choiceg

of =agnitude and depth of this event and he should thoroughly study its '*

duration, high frequency cont ent and other near-field effects, particularly ;

as they affect the shape of the design response spect ra.[

1284 150 ;

. .

I

- 300RORGNR :-

.

.

SHO?.E-PARALLEL A!*D SH0r? !;0P"AL Pt.ULTS.

The Mission's review of marine geophysical data in the PSAR as well asother data provided by P.A.E.C. and discussions with Dr. Sonido in May 1978 |and the Applicant 's consultants in July 1978 indicate possible shore parallel Ifault system approximately 15 to 20 Icn off-shore the plant. The Nisaionunderstands that this =atter us also discussed with the Applicant in March "

1978. Lacking streng data, to the contrary, the Mission believes that the ;;

quality o,f the data obtained from the single channel analog system precludes 3

firm resolution of the seismic risk associated with the possible faulting. hConsequently, we judge that this fault =cne should be taken as a source of [a maximum earthpake in developing the sciamic design basis for the site.However, the Mission believes that the risk associated with possible fault- 4

e

ing in this zone to be lower than acsociated with the high =agnitude event J*

postulated to occur in the subducting slay and the higher magnitude shallow "

l-random event . !

u

With regard to shore-nor=al faulting, there are several icolated piecce, *

of data in the PSAR which, when considered together with discussions heldin Jtily 1978, suggest a need to re-consider the question of chore nor=al *

faulting in more detail. Specificallyi the abrupt scarp-like bathymetry on u4the South side of Napet Point , the subdued manifestation of this scarp-like a

topography in the acoust to basement as revealed by the Marine CeophysicalSurvey, the align = ant of surface lineatiene en land, as revealed by topo- p

- graphic caps, 'SLAR, Landsat and Ther=al IR i=agery, with the scarp-like ljS.,

seaficor feature - all cont ribute to a concern that requires i nher detailed v, consideration by the Applicant . Specifically, the Mission reN 2 ends additional -

field investigation of possible faulting in the vicinity of a line running dbetween p

M 1,619,000 N 1,618,0C0 N 1,617,000 (,LE 426,875 E 426,500 E 426,175 a-,

, -

bas can be plotted on Figure 2 51 - 55 of the PSAR and on Ficure 1 of ***

nEngineering Report No. 4. The results of this investigation should include..

conclusions regarding the i= pact on plant design and operation if the fault L

L' 'i'' * -1284 ]51 *

The Missics observe:i two areas on the in testigation which could have '

receive:i additianal effort and support. Firstly, tho =icreear:hqucke survey k

rwas minimal and together with the lack of detailed study of low =agnitude t

event s cn:1, cons:quently, :locs not prove to be highly contribu:ory to the under-f

P00R ORIGINAL~

!

. - _

.

.

_7-

standir.g of the seic=otectonic situation and the assesc=ent of faults andoverall seis=ic risk whereas a longer, = ore detailed survey =sy have beenvery helpful. The invectigation of some of the linears as well as thether=al springs is regarded as =inical and not in keeping with the quality

E

of other parts of the inventigation..

VOLCANISM.

The #1 pot site is unique to the nuclear industry in so fa - as thei

risk associated with eruption of nearby volcanoes. The only =odern plant fwhich is designed to account for volcanic eruption is the Pebble SpringPlant in the Unit ed Stat es. This plant is located 128 k= from the nearent

,

volcano and consequently only ash fallout is a consideration. Jt the NapetPoint site, the nearest volcano is 9 k= away. Therefore, the quet.tton ofvolcanic eruption deserves extre=ely careful consideration at this site. I

It is e=phasised that the Applicant and his Consultants have perfor=edexter.sive and in depth investigations to answer the questions raised by thr.tvolcanic threat. Moreover, the Mission believes the investigations perfor:ed .

=aet the stat e-of-the-art how a volcanic hazard is to be envisioned. Also,.

detailed, presentation of the data during the =eeting is appreciated. In i.addition, theJ Mission acknowledged very =uch the valuable contributions :ade fby the Volcanological Review Co=sittee in that =e et ing.

After thorough discussion of all the geological and volcanological.

provided data together with the Applicant and his Consultan;s, the Missionfconcludes that there is still a great deal of uncertainty of renewed r

volcanic activity at Mt. Natib. Moreover, it cannot be judged as such thatIa future eruption is confined to the east side of Mt. Natib, i.e. thet

, for:ation of new volcanic centres on the west flank of Mt. Natib is not{

considered to te incredible. More appropriat ely, the erupt ion ''of the Mt. Natib Volcano Co= plex and all of the hacards associat ed with it

should be taken as an ext rs=e environ = ental loading si=ilar to the Safe|

Shutdown Earthquake (SSE). Consequently, the Mission deece that the hacards I

associated with such as enption, e.g. ash fall, i= pact of volcanic e;ecta, |glowing avalanches, overflowing gas-ash e=ulsions and gas accu =ulation as ;

well ac laharic =ud flow should be taken into account.

PDDRORGNAL -

1284 052.

'

.

-8- .

Means should be provided to mitigate against a. radioactive release in

the event of a volcanic eruption of Mt. Natib. One possible means ofI

accomplishing this is ,he recoval of all fuel from the site to an off-site ;

storage area away from the volcanic threat. This consideration recognizes ;

the assessment made by.the Volcanological Review Committee that the renewed}

eruption of Mt. Natib can be reasonably predicted three c:enths in advance (

should a per=anent , sophisticated and well =aintained volcanic surveillance [Isystem be displayed. Moreover, it is necessary to establish volcanologicall

baseline. criteria gathered by the surveillance system which should initiate L

k.

without delay the possible shutdown of the plant as well as a course of actionsh

regarding preteetion of all fuel.

'

The Missions understands that the surveillance system will be int.. .lled

as soon as possible in order to collect appropriate data necessary for the|

definitien of those baseline criteria before the plant will come into tIoperat ion. The Mission not es the advice given by the Volcanological Review

Committ ee that the surveillance syst em should provide seismological, geodetic,gravimet ric, 7:.gnetic, and thermal data.

CEOTE0'DICS

IThe behaviour of the soil beneath and adjacent to the foundations under.

static and dynamic conditions has been reviewed on the basis of the related

PSAR sections. During the meeting in July 1978 additional reports wers !

analyzed. >~

rI

SOIL INVESTIGATIONS

The results of the progra==e of soil investigations perfomed at the :

site and in the laboratory indicat e that from the st ratigraphic point of -

t, view, the Safety Class and Seismic Category 1 stmetures are underlain by ga rock-type coil or by a cont rolled backfill. The numerous stratigraphic '

borings and coophysical investigation have been found generally adequate in,

nu=ber and in type. The foundation soil can be characterized in a very gsynthetic way by a compression wave velocity varying from 1500 to Soco =t/sec i

twhich allows us to classify the site as having stiff soil conditions.

|

;.

_ -

-9-

,

. _ _

Civen the gross non-homogenity of the foundation c:st orials underlying-

the site as determined from borings and trenches, the Mission raised a concernwith respect to the reprasentativeness of the undisturbed samples used formeasuring soil behaviour in the laboratory. An exceptionally high reduction |

in shear modulus at high at rain levels, i.e., "st rain-softening", is indicat ed '

by the laboratory tests on samples of rock-like saprolite and weathered rock.This concern would diminish considerably for dynamic shear strains less . ,

~4than 10 The Applicant should confirm that the dynamic shear st rains-4will be itsa than 10 as revealed by the final soil-structure interaction

analysis.

Along this same line, the Mission has concern with the "zero strain"shear wave velocity data. The in situ d$ta from a single vertical boring(No. JF1) do not permit straightforward e:ctenaien to the soil profile usedfor analysis and design. Furthermore, it was necessary to utiliza correctionfactors to cause agreement between laboratory data and field data. TheAp.nlicant should review all of the "zero strain" shear wave velocity data i

iand confirm that valves actually used in the soil-structure interaction i

analysis are representative of site conditions. I

STABILITY OF SU3STFACE MATE 3IALS|

,In spite of the limitations of the data as described above; the Missionconcludes that the subsurfacs natorials at foundation level of Class I struc-

|1

tures have adequate strength and compliance ao as not to pose a threat to thesafety of the plant. However, we note that the PSAR does not report specific-ally such important parameters as the design crit eria for dynamic bearirg

g

capacity, factors of safety, design water tables and assumed pore pressure j

condit ions. We reco==end that the Applicant perform a dynamic bearing capacity [analysis under the worst combination of SSE loading, appropriate dynamic soilparamet ers, and design wat er tables; factor of safety greater than 2 againstbearing capacity failure'should be assured. I

t

[SLOPE STA3 LITY,

The slope stability analysis of the natural slopes and cut slopes atthe site have been performed using the Simplified 31 shop method. This method

{~

can include the combination of the seism:c forces (vertical + hori: ental) and 't

assumes a slip circle as the failure surface. Fact ors o f cafety of.1 5 and 1.1 iconsidered accup:acle respec:ively for sta a by the

1284 054 |

t,3 a. . . . . - - . - . .

|M!U g d J!.d[ 9 4 *V0U. Ed *:Yn . .. .

,

- 10 - p;.

Owing to the interbodding of the several layers i.nd to the rocky type -

of soil, it appears that also a wedge type of failure with due considerationgiven to rock joint systems should be considered by the Applicant in a newanalysis. Also, the new analysis as well as all previous stability analyseufor both natural and cut slopes should consider possible amplification effectsof the topography. The Mission also believes that the stabi~.ity of the coast-line scarp on both sides of the plant as well as on the seaward side deserves .

additional detailed stability analys.% under extreme environmental leadingcondition's, again with the consideration of topographical ampli'fication effectsand rock joint syste=s.

SOIL RESPONSE UNIER SEISMIC EXCITATION

The particular topcgraphy of the site a steep-sided, relatively narmwpeninsula graded from about elevation 35 dcwn to elevation 18 and rising upto Mt. Natib, suggests that surface ground =otion might be sevenslyaffectedduring an earthquake by unus tal wave propagation phenomena. Several accolo-grams recorded during the 1971 San Fa-asde canhquake showed unusually highacceleration spikes which are attributed to pa:Sicular site t.cpography. At .

%sit es locat ed on slopes in Italy, high peak accelerat ions were recorded dur-ing the Friuli earthquake of 1976. Considering the distinct topegraphy of 4this site and the relatively high Safe Sh2tdown Earthquake, the ' Mission Trecoc= ends that this aspect of seismic responra he thoroughly investigated.

Moreover, the Mission points out the conditions and typerof earthquakes'

used in the development of design response spect ra in Regulatory Guide 1.60.'.'Considering the particular conditions at this site i.e. a possible nearby

earthquake with stiff soil conditions, the Mission is concerned with the$possibility of high frequency motion having a=plitudes higher than these 9

.associr.ed with the Regulatory Guide Spectra adopted by the Applicant. g~'

.TbS*RUC*U5I-TC-STRUCTURE !!."'ERACTICN c?

*' The Applicant should provide his design basis for nitigating againsts

"nav.:ering" effect s during the SSE. (t

P00R OR M imm,.- p. O L. . m . - k

,. .

"30 4

- 5- - -

< cu ei

.

. _. _ _. _ _ _ . _ . . ._

-

*rptI .. k- 11.,

Q $N' Yd hSSII.- ? RUCTUS.E INT'MI.TICN*

5The Appl.: ant hss adopted the finite element technique for asseccing

hcoil-ct ruct ure int erat. ion. Generally speaking, the .atalysis has beenperformed within wvitten siipulations of the regulatery guides and standardreview plants conventionally used for this type of analyses. However, theanalysis fails to evaluate the possible a=plifying effects (accelerationand frequency) of the peninsula topography and the possible reduction in ,

geometric damping associat ed with the topography. Further= ore, the analysisseems to suggest exceptionally high strain sofsening which should be re-assessed by the Applicant. Both issues, i.e. Topograph! cal effects andStrain Softening as well as the assumptions for the inz t tal shear moduli,should be investigated by the Applicar

EARTHQUAXE INSTRUE 7PATION

The Mission understands that an earthquake =onitoring syst em will bepa:t of the surveillance system to monitor preconitory signs of a future

possible eruption of nearby volcanoes. In ?Ad. tion to this Surveillance

Syst em the Mission :-ecommends that atrong c:otion accelcroceters also beinstalled i==ediate:.y at the site. These accelerometers should Le set in

a series of different locations much as treefield (off peninsular), on thepeninsula away frem the foundation,on the Cat egory 1 foundation =at , andin the strdcture in accordance with Standard Practice.

6

CONCLUSION

Based on infor=ation provided in the PSAR and in the supple =entarycaterial as well as provided verbally during the discussions with the expertsof PAEC, Ebasco, and Westinghouse, the Mission wiches to express its majorconcerns in the following areas and as detailed more fully in the text of

the report .

?0DR ORGINAL~

VI3RATORY GROUND MTION AND SURFACE FAULTINO

(1) The Safe-Shut down Earthquake should be re-evaluat ed consideringa possibly higher magnitude randem shallow earthquake postulated i

to occur beneath the sito and a high magnitude earthquake postulated .

to occur on the subducting slab beneath the site at 1:s closest'

approach t o t h o s it e. A third event postulat ed to occur in tone .

of possible offchore faulting is judged to be of a lower ris ' levelso long as these two earthquakes are reconsidered. '284 256

x : .f.? T,&'

*V ' ' ~ ' ~ t31 . -

u.u..; .

.

_ - - _ - - - _- .. - .-. ..--. . - - .-

,-- r ,, m p - , -. - - , . _ ,

1.

'- .---......a.

'

- 12 - -

..

(2) Additional investigation and analysis are required to resolvef.

concern with evidence for a shore normal fault mnning parallelt

to and i= mediately south of the Napot Point Peninsula.||

hVOLCANISMI

(3) The emption of Mt. Natib is a credible event which should be ;

taken into account in design. This requires consideration of I

. excessive ash fall, glowing avalanche, gas accumulation as well fas laharic slides. '

(4) The immediate installation of a sophisticated and well-maintainedvolcano surveillance syst em in combination with well-defined base-line criteria and subsequential precedures and action plan concern- I

ing the operation and/or shutdown of the plant is st rongly recc= mended.L

(5) one pessible solution to mitigate against a radioactive release inthe event of an eruption of Mt. Natib is the removal of the fuelto an off-site storage location upon advance warning by a surveillancesyst e.n. The Mission bel'ieves that this alternative, as well as otherpossible alt ernatives, deserve consideration in developing the pro-,

cedures and action plan mentioned above.t >

.

R)UNDATION ENGINEERING '

F

. (6) The geotechnical investigation conducted by the Applicant is[

acceptable for the particular soil foundation characteristics. -

The site appears adequate from a static foundation engineeringpoint of view. Topographical and local effect s on vibratory ground I

motion, design reeponse spectra, natural slope stability, and cutslope stability should be properly investigated; soil-structure.

,

interaction analysis should also be revised accordingly if appropriat e. r;iClarificatica is needed with respect to the initial shear moduli andi

-

"st rain soft ening" soil charact eristics used in the dynamic analysis }>present ed t o dat e.

P00R ORGK1 ;

i

1284 057 6

cmm 2 : : e ib O bN db;l. tt-,

es,. e r e- * " "1-

b . .. T'

,

- 13 -.

,I;]i 30.3::- ...

U 1-i'J"w;il$d.

Respec fully submitted

/L n [89W' I b W. Harsch,

ily (J !'

/[ /1 h, P. Mussi'

|,f

- vg .

i

(6,f ( % P. Rizzo.

_

/9 % E. Iansiti- w

**

v ,,

,. .

7 July 1978 :,

,

* .

. ., ..

,I -

. '. .

- *- . .

,

e

.

P

e

e

0

.

:PDLRUR8NAl.

'

1284 958ru m e. -- J,- u;w w. .. .. . .:

. - - ._ ..

~

7...s.,..

. . ..

_

Ie. - . . . . - . . . .

MilO|. 9F !- Uris;Ly% $s..''E9r

- ~ - - - -

.u . .D|r- 14 - *'

.

L-.

ANEX 1 M

!baList of experts who attended various meetings in the Philippines from

-

1 - 9 May 1978g

- wSAITTY MISSION EMEERS

W. Harsh Swit zerland-

P Mu :1 Italy-

P. Rizzo United States of America-

E. Iansiti 7,y,g,gJ. McCu.llen

,

PIIILIPPINE ATOMIC EERCY COMXISSIONr

Z. M. Bartolo=a I)eputy Commissioner-

R. L. Palabrica Acting Manager *-

Geologist $G. Santos -

gE. Hernande: Geologist %

-

NATIONAL POWER CORPCRATION

R. B. Blanco Manager, Special Pmjects Group -

-

WESTIN0 HOUSE ~

.

-.

J. Woeber Site Manager .'-.

W. Corcoran - Quality Assurance-

J. Xaviar Site Engineer-

aIAEA exPm

D%.

C. Willic,

_N

P00R ORGNAL FR

1284 259 l'k

- u t vur.{~ . . -]!Pi,Al 3

''"~

4 ~-y.

|-

.

,._ _ _ . __ _ _ _ _ - -

._ _ _.

. - - . .--

5QQQ$h.i."' _'' ~'

h Jhhjbh O]-

es.,

"U . . ._ t

- 15 -

ANNEX 2

ITINERARY OF THE VISIT IN THE PHILIPPINES

30 April 1978 Safety Mission nenbers arrive in Manila-

1 May Discussion on safety problems !-

!2 May Discussion at P. A.E.C. and first review of documents-

!3 May Review of docu=ent s at N.P.C.-

4 May Helicopter visit to sit e, sit e review and discussions-.

with centractors and consultants5 May Discussion regarding main points arising in site visit ;

-

at N.R.C.|

6 - 7 May Pirst drafting of report-

8 May Meeting with P.A.E.C. 8-

i

L

TIE SCHE!ULE OF ' IRE KEETING HELD IN VIENNA

3 July 1978 Discussion in IAEA Headquarters with the experts and-,

P. A.E.C. expert s

4 - 6' July, Discussion with P. A.E.C. , P.N.P.C. , E2ASCO , West inghouse-

and other IAEA staff neebers and experts '

I-

I7 July Preparation of the report t

-

i

iL

ii

I

t

a

1

'e

e

1284 ]60

nym g e --

,. ..

o is b l.h . ; .. . ;u_,.

.

. . _. - - . .. - . . - -

- i t, - T:<"----"--"- p;p.y z p, .. %,

,

WeGYLN $0.i & ;- ~ ~ r- '' -.

Ala:1:X 3 g g,

' hLIST CF ADDITICUAL 'ACUE!.TS PRESEUTED FCR THE WINO IN VIENNA

3 - 7 JULY 1978

PNPC - E3ASCO, Geology of Unit 1 Excavation. February 1978

PNPN - E3ASCO, Hagae Nuclear Power Plant , Site Confirmation decort

ESASCO, PNPP - 1 PSAR, Amendment No. 3 .

EBASCO, Seismic Risk Analysis for the Philippine Nuclear Power PlantUnit No. .l.

ESASCO, Seismic Velocity Data-Philippine Nuclear Power Plant. December 1976.

ESASCO, Vibratory Ground Motion Addendum 1, Engineering Reput No. 2, -

May 1976.

E3ASCO, Philippine Nuclear Power Plant , Unit 1. Response to letter of

20 December 1976..

'E3ASCO, PNPP 1, Additional Safety Related Data. June 30, 1978.

E3ASCO, Philippine Na*ional Power Corporation. Philippine Nuclear PowerPlant Unit No. 1, Volcanic-Seismic Surveillance Progrs==e.

E3ASCO, Geolcgic Ha:ards to PNFP Unit 1. July 1977

E3ASCO, PNPP, Additional Safety Relat ed Data. June 30, 1978.

. E3ASCO, PNPP ,1 PSAR, A=end:ent No. 3

E3ASCO, Philippine National Power Corporation, Philippine Nuclear PowerPlast. Engineering Report Number 1. February 1976.

E3ASCO, Addendum to Engineering Report No.1, Philippine Nuclear Power Plant.

E3ASCO, Philippine National Power Corporst:en, Philippins. Nuclear Power PlantUnit No. 1. Engineering Report Number 2. April 1976.

ESASCO, Philippine National Power Corporation, Philippine Nuclear Power Plant ,' Unit No. 1. Engineering Report No. 3, Volu=e I . September 1976.

ESASCO, Philippine Nuclear Power Plant , Unit 1. Engineering Report No. 3. Voluso I:Sept ember 1976.

%E3ASCO, National Power Corporat ion, Philippine Nuclear Power Plant , Unit - (No. 1. Ingineering Report No. 4 February 1977 e.,

u-

[!'E3ASCO, National Power Corporation, Nuclear Power Plant , Unit No. 1.Engineerir,g Repor: No. 5 May 1978. J 28l| ]6)WESTINGHCUSE, Seismic Analysic-Philippines Nuclear Power Plant Unit No. 1.February 1978.

-

4, %p. .q ; , - . - i- . . . - - - . . . . . - _ . . . . . . - . . . . . _

_

*a-. ...... ... w . . . _ _ . . _ . . _ . _ _ . _

:.a - w .. a m .- ,. .

.

.

_ __ ._ .__ _ _ _ . . _ _ _ _ _ . . _ . _

.7 -.

,. ym m. r r . . . -,

'

All;,7x 4 U. :...... .

LIST OF EXPERTS '..TO AME::DED tnt ' TIE:'.:A 22C?ING 3 - 7 JiluY 1978

P.A.E.C

Mr. L. D.' Ibe

Mr. C. Santos

N.P.C..

Mr. A. Alcara:Mt. H. H. IbarraMr. J. C. Torres

WESTI?lCHOUSE

4Mr. T. E. CampbcIl1

Mr. F. Loceff ',

Mr. J. W. MinogueMr. W. S. Wilgus

E3ASCO SERVICES

Mr. J. CilmoreMr. J. L. Ehas:Mr. J. FergusonMr. I. N. Cupt a

gMr. F. Snideri

Mr. N. R. TilfordMr. C. F. Whit ehead

Mr. P. Ragland

Mr. A. McDirney - Cent er for Volcanos

Mr. A. L. Odum - The Florida Stat e University {T

} (kihlMr. J. de Boer - The Wesleyan University '

IAEAi

Mr. W. M. Harsh - Mission Expert Mr. Ha Vinh PhuongMr. E. Iansiti - Mission Expert IAEA Legal Counsel to theMr. A. Earbassioun MissionMr. F. P. Mu::i - Mission Expert

j} ,} |Mr. P. C. Ri::o - Mission Expert6

tMr. M. Cosen. . , ..

{Mr. C. A. Willis:

. . . ._ . _ . -

.

P*~

, ,bi 1. /? '

.

' -- .. 2t

5

V

gSIAIUS SUMMARY EPORT ON ESOLUTION OF ISSUES RAISED '.

BY THE 1973 IAEA SAFETY MISSION TO THE PHILIPPINES 5

MbE

I.CHARLES A. WILLIS dNuclear Reactor Safety Expert EInternational Accmic Energy Agency I :,t

E

5ese

'

m.>=

E1:/4/1'? n

Declassified ByJ .R/Shea : DIR,IP,NRC k

Ref. State 9/17/79 memo grY%se-M

' -

fEClassif so n f

~

, _

~'

T ):-_ _

.. . ~ . ...

_ _

=.

E 0:0~

-

*.. , . . . . . .

p 16 W ~ g,

March 1979 / 5w

PHILI??INE ATCMIC ENERGY ColeilSSION %TQuezon City p>

1284 063 [N $~TP/sskamp 't val d as ema en )f t.

c.1/ssificat on ' cec use F IA r quest / ibN

,

'NF. NSL pending cla ifi ation -c S e4 '%rdce ed 5 4/79. Pro ct{/

[,.mJ"1fg/_g.t' -.

"-

. hai .. n, NRC, as GO 1 65. I f ,gg'' s

.. , ; ,- .i gin.& i_ y====rm/ -|,| n,- @nelew | p.i:et een

.. . . .. .

,, t0 r(1 ,: 3., . a ., ' .. / /// / [/ yArJ .my.~. \.- ;;; }f t :: : . n2 e--- f.

g g f fy c:sc,:c=;'.u1.. ! h*

I J lIQ m _,J tJ "

,. _~ -

. _- 1 1 -. ..

i. -

.p..