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PAEC EVALUATION OF THE RESPONSES [gi'

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d't P

ON THE ISSUES RAISED || L.

O jI CBY THE 1978 IAEA SAFETY MISSION2P b

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Declassified By 't fJ. Snea+0IR,IP, NRC ;l

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Ref. . tate 9/17/79 memo !

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!N.g..

22 March 1979 ?Manila, Philippines [g-

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PAEC Evaluation of the Responses on theIssues Raised bv the 1978 IAEA Safetv Mission ,

*

Backcround

The Philippine government is now undertaking the i

'

construction of the first Philippine Nuclear Power

l' APlant. The Philippine Atomic Energy Commission (PAEC) g

.

has been charged with the responsluility of licensing,

I.

and regulating nuclear power facilities. For the first i

unit, the PSAR was prepr Td by the Applicant National |t

fPower Corporation (NPC) in accordance with a formatr

patterned after that of the U.S. Nuclear Regulatory j

i

Ccarission (USNRC) and submitted in July 1977 to the j

tPArc, j

In order to enhance its capability to resiew the

PSAR, the PAEC requested in July 1977 IAEA assistance It

t,in selected technical areas where it felt at that time ithat local expertise had not been developed. The joint (,reviews of the safety mission sent by the IAEA and of

the PAEC staff revealed that the PSAR for the PNPP-I:

appeared to be the most comprehensive ever provided:

for a nuclear power plant project in a developing

country. These reviews resulted in a number of ques-f

.

tions and requirements for further investigations. !

PAEC reviewers raised a number of issues related ;I

to the geology and seismology of the selected plant '{u

1284 -)17:,

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site, especially on the subject of the Safe Shutdown

Earthquake (SSE). Pending resciution of these issues ,

'

con-truction work on certain buildings has been al- 8 i

lowed to proceed on th , basis of a Limited work Autho- p gb* '

'

risations (LWA). At the sams time, in recognition ofll <

PAEC [the importance of the site-related safety issues, !' r

again requested IAEA assistance for another IAEA safety f

mission that would concentrate on geotechnical consider- g

[ations. The mission was sought in the fall of 1977 but

t

Because gactually reached the Philippines in May 1978.of the absence of experts from Westinghouse Interna-

;

tional Projects Co., (WIPCO), the m 'n project con-I

tractor, and ESASCO, the NPC consultant that assisted ,

V.

' lkin the site investigations, during the initial dis- k

k,

cussions with the Mission in May, there was need there- W%i

fore to reconvene the meeting in Vienna in July 1978.-

Based on the information in the PS AR and sup- ,

e

plementary materials (Table I) submitted for thee

Vienna meeting, as well as discussions with ESASCO, j

WIPCO and NPC, the IAEA Mission reccmmended to PAECThe work . f.'the need for additional work in six areas. p*

,

'Fincluded additional field investigation and analyses. *k

[

After a study of the IAEA Mission report and its <=.4'I

recommendations, PAEC established requirements which ,,

,;

li

1284 J18 :

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would address each area of concern of the Mission.Several consultative meetings were then held with

NPC to further explain and clarify the issues raised

by the Mission and the PAEC requirements. During .,

h ithese meetings preliminary plans for the work needed !

s

to address the safety issues were drawn up, including

a reasonable timetable for the work and submission of fI

requisite reports to PAEC.

The issues could be grouped in?o two; namely:

(1) those that need to be resolved in the earliestI

Itime possible, such as the matter of t.he vibratoryi

ground motion, random shallow earthquake and founds- |

tion engineering, and (2) those that can be resclvedf

at a later time such as the volcanism issue. PAEC Fsb

then issued an order for NPC to resolve the first 4*

k-#group of safety issues and submit its finds andreports by November 24,.1978 and which was extended

i to March 30, 1979. For the volcanism issue, PAECjgave N*rc until August 28, 1979 to submit its report.

The periodic meetings between PAEC and NPC con-'

rtinued after issuance of the order to assess the.s

progress of the work on the : ssic a concerns. During

'

this period, PAEC was also conducting periodic ins-

pection work on the additional field investigations .

.

1284 119

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that NPC was directed to perform..

Each of the Mission's concarns, the associatedand the

PAEC requirements, the investigations by NPC,

corresponding PAEC evaluation are discussed in the,

following paragraphs..

.

VI3RATORY GROUND MOTION AND SURFACE FAULTING _

Two of the Mission's concern were in this.*~

The first involves the Safe-Shutdown Earrhquake (SSE)

and the second deals with a possible Shore-Normal

Faulting.

Safe-Shutdown Esrthcuak_e.\ .

"the Safe-Shutdown Earth-The Mission feels thatquake should be re-evaluated considering a possible

hi,gber magnitude random shallow earthquake postulated<

to occur beneath the site and a high' magnitude earth-

quake to occur on the subducting slab beneath the siteA third eventat its closest approach to the site.

postulated to occur in a zone of possible cffshorefaulting is. judged to be a lower risk level so longas these two earthquakes are reconsidered."

,

1. Random Earthcuake_

In the PSAR, the applicant examined every earth-

quake in the Central Luzon Tectonic province occuring.

1284 ]20

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with magnitude exceeding 4.5 and with known location,

and associated each one with a tectonic feature. It |

concluded that the random earthquake at the site used ',

to determine the SSE should be of magnitude d.5. 1*

1

1

The Mission stated that the tectonic model deve- -

, ,

loped by the Applicant does not adequately define the

West Luzon Trough and proposed that the West Luzon .

fTrough be considered inactive. In such a case, the ,

two earthquakes of magnitude 6.25 associated by the

Applicant with the Trough should be considered in the ft

dete=mination of the floating earthquake. The Mission!

was also unable to assess fully the possibility of a ;

higher magnitude shallow event occuring beneath the site |L

because of the lack of a complete composite epicentere.-

' map and a composite earthquake catalogue. -

5IThe Mission suggested ,so alternative approaches :-

E.for addressing this issue. In the first approach, the r-

Applicant could do the following:.

(1) perform thorough and detailed analysis'E

of all available earthquake data; and, g

(2) relocate those events within the bounds f.

'I

of the Central Luzon Tectonic Province. l$f

!!1284 121 ;)

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Those events which cannot be assigned to the Manila ,

I iTrench, the San Antonio Fracture Zone, Manila Bay Frac- ;

,

Iture Zone, the Taal Fracture Zone, the Philippine Fault!

,

cr the Iba Fracture Zone should be treated as random'

and assigned to the province and should be postulatedb k

to occur beneath the sitc. I,, ,

i L

As an alternative approach, the Applicant couldi 6

gpostulate a random event having a magnitude in the ;

Lrange of 6 and a shallow depth (less than 30 km) coF

Loccur directly beneath the site. In such an event the

applicant should develop strong technical basis forandhis choice,of magnitude and depth of this event,

L'

should thoroughly study its duration and high frequency I

content, and other near field effects, particularlyce:

'as they affect the shape of the design response spectra. gg:. .

' -

The PAEC instructed the Applicant to consider the -[=-

said alternative approaches and in addition, icok into m

PAGASA (Philippine Weather Bureau) reported earthquakea , ,

Iof high intensity (exceeding MM VI) in the Central Lucon|

Tectonic Province for which the epicenter locationsIIwere not specified.\f

-

In responding to this issue, the Applicant chose g!.Pthe first approach suggested by the IAEA Mission. It

fkhas prepared a composite earthquake catalog, an epi- A

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1284 922 |o.i

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"'and relocatad a number of earthquakescenter map,

including twe (2) earthquakes of magnitude 6.25 which

were of specific concerns to the IAEA Mission. These

two earthquakes have been relocated using computer

analysis developed by Boltf and associated with the

Manila Trench.

For those earthquakes whose epicenters were un- ,

known and for which only the intensities were given, the

Applicant contends that these observations were made

prior to the installation of seisma a measuring instru-Thus their effects were described in terms ofments.

intensity which are observations en man-made structures

unlike earthquake magnitude which are instrument mea- ,

surements. The Applicant feels that a high degree of

' subjectivity entered into the assignment of intensityvalue to these earthquakes and therefore attached very' -

little significance to them compared to the instrumented

earthquake.. -

fWith the relocation of the two, 6.25 magnitude,

earthquakes to the Manila Trench, the association or ,

other high magnitude events to the known gaologic.

features in the tectonic province, and the explanationi

given for the high intensity earthquakes with unknown :

I

epicenters, the applicant cont md3 that these provide ;

i.

1284 923

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the basis for their selection of a 4.5 magnitude for i ,

i iIthe random shallow earthquake.

The PAEC finds the approach taken by the Applicant- e

in addresseing the issue acceptable.'

r

'

2. Earthcuake Nn the Subductine Slab tF L-

The Mission reccmmended placing the Manila Trench r yi E

earthquake on the top of the subducting slab directly p,.

Fbeneath the site. Specifically, a magnitude in the

r-

range of 8 event at a depth of 50 - 70 km below the '

iEsite was reccmmended.ED

In order to address this issue, PAEC directed the g,

|Applicant to do the following:

(1) Evaluate the maximum events on the

descending slabs from the Manila 22,

E'

/ Trench and the West Luzon Trough, at [[c

their closest approach to the site. {<,

l'In his Status Report to.the PAEC on the Resolution i

#of Issues Raised by the 1978 IAEA Safety Mission, Charles jA. Willis, IAEA Nuclear Reactor Safety Expert, observedthat: "There is reason to believe that the issue ca.. be

~

satisfactorily resolved. It is noted that Murphy and p%.

O'Brien(2)suggest that local magnitude of 6.25 corres- . g7ponds to an epicentral intensity midway between Modified gMercall (MM) VIII and MM IX and that (using Western US gdac;, Figure 1) this implies a maximum horizontal acce- ps

leration between 0.17 g and 0.3 g. Also Rood et al(3) p,

suggest that current US NPC criteria are satisfied by ga 0.25 g SSE where the rc.idom earthquake intensity isMM VIII. Thus the present PNPP-1 design value of 0.4 g -

is likely to prove adequate". ,p

.i

1284 124 i. . . . . . . .

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(2) Justify the scaling approach employed ,

ii

in the calculations. ,

Calculations were reported by the Applicar.t in j

iI '

which scaling was done using 16 response spectra from,

Iseem to11 earthquakes in Seattle, Washington that I II

correspond to the PNPP-1 situation. For computation o

|'

of maximum scaling factors, the attenuation relation- |8

f'

ship proposed by Katayama was employed. The ApplicantI

ijustified the use of the Katayama method by citing the I8fact that the tectonics setting in Japan is similar to[

that in the Philippines with both countries lying alongthe circum-pacific belt with its associated subduction |

|The calculations indicate that the SSE value of gzones.

0.4g would be exceeded with an earthquake of magnitudee,

8 to 50;km depth but not for magnitude 7 to 70 km. [i

The Applicant, however, believes that an event of-

-

magnitude 8 to 50 km. beneath -he site is not likely

to happen. Firstly, at this distance, the earthquake ?

would be located in the West Luzon Trough subducting 'I!E

slab. The PSAR has shown that this slab is inactive i)ik

!vbecause subduction ceased during the early to middle'

t,

'I

Phiocene period. It will require a minimum of 70 km I|before a postulated earthquake falls on an active sub- ;.

ducting slab, i.e., the Manila Trench. Secondly, as

t

nV

1284 J25 |,

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far as the earthquake magnitudo is concerned, the Ap-

plicant has submitted material which contenes that thelargest historical earthquake of intermediate depthoccured on Nbrch 28, 1940 with focal depth of 200 km

and a 6.75 magnitude. The Applicant feels therefore, :

that.an assumption of magnitude 7 event occuring at a ,

depth of 70 km, which was employed in the calculations.-

1

f

6is conservative. i

The PAEC finds the explanation and justifications ,

of the Applicant on the maximum earthquake on the sub- ,'i

ducting slab acceptable and feels reasonably assured that ;I

!the 0.4g SSE alue will not be exceeded. I

- i

3. Offshore' (Shore-Parallel) FaultincA review of the marine geophysical data in the PSAR e'

i.

as well 'as of other data indicate pcssible shore paral- I

lel fault system about.15-20 km off Napot Point. The

Applicant has provided documentation contending that

(1) the indications are slump features, not a tectonic [l

fault; and (2) even if these were a tectonic fault in iri6

the indicated location, it would be too short to pro- ,

is- ,6

duce a strong earthquake to. increase the SSE. gg

No further work in this area was required by the f|t

PAEC because the acceleration frem a maximum earthquake i;n-

I |t1

j':1

1284 126 :

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on this possible fault would produce a value less than ,

the present SSE. ,

i

*.

B. Shore-Normal Paultinc ,,

I:

The Mission's second conclusion was " Additional { f

'i Iinvestigation and analyse; are required tc resolve .

.i e.

'' 'concern with evidence for a shore normal fault running

r,

parallel to and immediately south of the Napot PointP

Peninsula". [

This fault was postulated on the bases of the

abrupt scarp-like bathymetry on the South side of

Napot Point, the subdued manifestation of scarp-like

topography in the accounstic basement as revealed by 5,

t

the Marine Geophysical Survey, the alignment of surface E-

alineations on land, SLAR, Landsat, and Thermal InfraK-c.

Red Imagery, with scarp-like sea-floor feature.

The Applicant has responded by excavating two Eit.

trenches, approximately 4 to 9 meters deep and a side

cut with approximately 2.5 meters of exposure. The p...

,

trenches have been inspected by the PAEC staff and -

IIIconsultants. The final report by NPC which concludes L b*

\-

that there is no capable fault in the suspected areas !Y'

was recently submitted to PAEC. It has been reviewedtt

IP\,t.

.-

1284 927 7t

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In order to further .

by PAEC and its consultants.

strengthen the conclusion reached by the Applicar.c,the PAEC has ordered that some confirmatory tests be ,

!condu ted on one aspect of the fic?,d investigation. !

These tests are currently being undertaken. jh

- r

VOLf:ANISMk

The IAEA Mission had three concerns in this area l

and each will be discussed separately sfter some back-

ground information.

t

1. Backcround i

Philippine volcanic activity is high: only Indo-nesia and Italy have experienced more volcanic dis- ,

h

asters. Taal, about 100 km away, is the active volcano9:

closest to the site. Mt Pinatubo, which is located 5.

iI

7about 60 km from the site, is considered inactive :i

because it has not erupted in historic times although

it did erupt some 635 years ago. Eruptions of these VFtwo volcanoes could affect the site by causing heavy f

ash fall.tThe concerns about volcanic activity are asso-*e

e

ciated with the old, but inactive nearby peaks of

Ttib and Mariveles. Mariveles is about 21 km from i

IL

!

1284 928

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the site and so presents the possibility of heavy ash j

i

fall. Natib's closest crater is about 9.5 km f rom the '

iiii

site and it is conceivable that a new fissure on the'

!western slope could threaten the site with glowing:

avalanche. Natib, however, erupted some 67,000 yearsr

ago.and is considered to be extinct. , p

P

The Applicant performed investigations and con- ,

sulted with some of the world's most eminent volcano- y

*

logists. The conclusiona raached were that during thet

life of PNPP-1, volcanic eruptions in the Philippines e

'are virtually certain, although an eruption in the

E

Bataan peninsula (where the plant is located) is con- e

t

sidered highly improbable. The plant, however, is ]being designed to withstand some amount of ash fall.

e-,

The' Applicant also proposed a volcano monitoring EE:/

system to ensure adequate warning if Natib again be- g="comes active.

2. Mount Natib Eruction -

The first concern of the Mission in the area ofI

volcanism was, "The eruption of Mt. Nacib is a cre- ;

t>-

dible event and should be taken into account. This -

t

requires consideration of excessive ash fall, glowing f(F

avalanche, and gas accumulation as well as laharic g mi

f,-

slides".

1284 029 iirW>>

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The Mission recognized the high quality of work

that had been done but concluded that there remained |.

| ,

considerable uncertainty about renewal of volcanic

activity at Natib. Furthermore, while the Applicant tk

cites historical trends and geochemical considerations b

i h

indicating that if Natib were to erupt, it will occur i

I

at the summit areas er the eastern side so that theplant would not be threatened by glowing avalanche, the p

Mission feels that a western slope eruption could not fF

be deemed incredible. The Mission obviously wantedr

Ifurther investigations of possible volcanic threatstt

to the plant. ,

The Applicant has provided additional information |L

on the volcanic threats. Clearly local topographym*

protects the site from most of these threats unless 2;.

:>

a new fissure develops and a flank eruption occursS=

-

'

ti -essentially at the site. The Applicant deems such an ,

eruption incredible. Even if an eruption were to9V

occur at or near the sc=mit nearest the site, topo-.

graphy would channel flows away from the site, protect- t pr'Ning the plant frem pyroclastic flows, laharic flows, ! P.*

and lava flows. The plant is considered safe from hE

if,.direct impact of ejected missiles by reason of dis-t

||. 1284 030 "o

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tance frcm Natib and the absence of a volcanic dome at -

,

Natib. Volcanic shock waves and earthquakes would be

far smaller than the design bases. The amount of ground l'

tilt considered credible at this distance should pose [*

no threat to the site.

.I k- The PAEC, however, cannot accept the position that E.

Ian eruption on the western slope of Natib is " incredible".i

The distance involved seem tco small to justify thet

implied large difference in the probabilities for s

Iwestern and eastern slope eruptions. Therefore, theL

Applicant has been directed to do the following: |F

{1) Calculate the probability of a p

|westems slope eruption. L

(2) Calculate the probability of a *:. _.

, Cwestern slope eruption without

; :adequate advance warning. e

i'

(3) Evaluate the consequences of an

eruption, simila- cc the 1911 Taal -

eruption, assa:c Ang it were to p.

occur on the western slope of Natib. 'F

The evaluation should include deter-'

E>mination of eruption locations from 1. g

which the base surge would not reacht F

the plant. [ [, .

P

1284 131 -

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.

This last evaluation should provide a basis for eva-

luating local topography. The 1911 Taal eruptien was

selected as a model since it was one of the largestso violent jhistoric eruptions in the Philippines but not

i

as to mask local topographic effects. The above |L4

calculations and evaluation are to be included in the I

report on the volcanism issue which the Applicant wasdirected to submit by August 28, 1979.

|Direct volcanic threats to the plant are provided

by ash fall and gases. The Applicante adalysis for ash ,

l

fall is based on an eruption similar to the Katmai j

volcano in Alaska which erupted in 1912. It shows that

Katmai-type eruption at Natib would result in 4 to 22 {feet of ash at the site while an eruption at Pinatubo

cPoint. ;would produce from 0.1 to 4 feet of ash at Napot,

"-

/ ;

From the ashfall analysis made by the Applicant,!.

PAEC is led to the follcwing conclusions:-

(1) Provisions should be made to protec- 7and Pagainst a core =etidown if Natib erupts- t

I

(2) The plant must be safe even if Pina-I

tubo, Taal, etc. erupts without ad-*,

' jvance warning,f.

.,

1284 132 .i

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o v e es =-

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t17 --

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As a result of these, FAEC has directed the Applicant

to include in its August 1979 report, assurances that ,

the plant would:

(1) Remain safely shutdown under a 22 ,

| ,

feet ashfall condition resultingr.

frcm a Natib eruption;-

(2) Be capable of withstanding an ash

fall of 4 feet in 60 hours without I

adequate advance warning of an erup-

tien.from Pinatubo, Taal or other [i

volcanoes.,

As far as volcanic gases are concerned, thei

I

Applicant has estimaced that dangerous levels of 3i_

gases at tr , s'.te would be limited to 3 hours or

hless. The PAEC has directed the Applicant to pro-i

vide available information on the kinds and quanti- g:tties of gases which might be emitted in a major -

eruption. Calculation: were a 1s 3 required of the-R

concentrations and integrated exposures at the siteO

frem eruptions of Natib, Pinatubo and Taal. [F

(~

3. volcano surveillance Svstemr

The Mission had recommended the "immediate ins- P

Ytallation cf a sophisticated and well-maintained vol- |

h,

1284 )33.

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iLcano surveillance system in ecmbination with well-

idefined base line criteria and sequential procedures {

! '

and action plant concerning the operation and/orI k

shutdown of' the plan". R

EEThis recommendation reflects the importar.ceD

placed by the Mission on the volcano surveillance [,

asystem. This feeling is shared by PAEC and the Appli- [

cant is responding appropriately. A plan has been ED

developed and is expected to be in operation by 1 Sep- [w

tamber 1979. ;

P*m.r'

4. Action Plan in the Event of Radioactive Release w

fdue to Mt. Natib Eruction A

The Mission indicated that one possible solution,

to mitigate against a radioactive release in the event E!E*

of an eruption of Mt. Natib is the removal of the fuel 5;~

=to an off-site storage location upon advance warning i g(

I

frcm a surveillance system. The Mission believes !i'

that this alternative as well as other possible alter-

natives, deserve consideration'in developing the pro- 50'

cedures and action plan metioned above.I

This statement indicates the Mission's concern ,.

ii'

that the detection of volcanic activity at Natib would j..

serve little purpose unless proper procedures for hh.e'I

rI

1284 934 .;.

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responding,to these warnings were developed and

implemented. PAEC agrees and has required the Appli-

cant to develop and justify appropriate procedures,

including consideration of fuel removal.

The Applicant has not, completed work in thisarea. The schedule calls for these procedures and

,

their justification to be submitted for PAEC review

in August 1979..

FOUNDA* ION ENGINEERING '

This represents the third general area of concern

,'to the Mission and they stated, "The geotechnical ,

'investigation conducted by the Applicant is accept-

I

able for the particular soil foundation characteristics. L

The site appears adequate from a static foundation.

~

engineering point of view. Topographical and local6

offects on vl.bratory found motion, design response

spectra, natural slope stability and cut slope stabi-

lity should be properly investigated; soil-structure y-P

interaction should also be revised accordingly if rt

appropriate. Clarification is needed with respect to e

I*tha shear moduli and strain softening soil character- ,

!

istics used in the dynamic analysis presented to date". I

i

'!.

t f

1284 J35

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.

The concern about topographical and local effects

result from the fact that the Narot Point site differssignificantly (perhaps more than other act0al sites)

from the " Infinite plane" presumed in postulating ai l

free-field acceleration and spectrum. The site is a,

small peninsula rising rather sharply from the sea : 1

Ifloor. On the landward side is a significant mountain. I

t

The Mission seriously questioned the shear modu-

lus-strain functmen experimentally obtained by EBASCO

and used by WIPCO in document WCAP-9187. The issue

is the reduction in the modulus at high strain. At

the July 1978 meeting in Vienna, NIPCO contended andI

has agreed to verify, that the dynamic strains do not ),

h.

~4exceed the order of 10 The variation is such that.

'

shear modulus at such low straAns is so small that *

an erro'r in the function would be unimportant. i

,

1. Tococrachical and Local Effects

In response to PAEC questions on the above con- )#cern, the Applicant has reported that WIPCO finds the

Irequested analyses to be beyond the present state-or- a

i'

the-art. Therefore, the Applicant is unable to supply F

*f.the requested information. In its analysis, however,

Ii

1284 936

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i'I

WIPCO has indicated that the methods used meet USNRC

=riteria, including the regulatory guides and the b

Standard Review Plan. WIPCO comments also indicate

that ,ne methods include conservatism to compensate ;

'

for these limitations in the analysis.t

- In view of these PAEC cannot make a judgment'

until the full report is reviewed; however, satisfac- |

i

tory resolution is expected. MI

2. Initial Shear Moduli and " Strain-Softeninc"

The Applicant has performed the re-evaluation and,

as a result, has revoked the soft soil case (of WCAP- li'9187) and has added a new parametric case of soilII

modulus. The strains were found to be less than

about 1.8 x 10~4; thus, the modulus remains in the j|

-'

IEflat' region.

' !PAEC has reviewed this response and found it ade- i

quate. PAEC is, also planning to refer the report

to its consultants for confirmation. |1 k

3. Cut and Natural Sloce Stabilitv fI

The slope stability question has been evaluated 5.

'

F

by the Applicant's consultant, EEASCO which has con- r<

tended that both natural and mane.:ade slopes willIi

. ,

1284 937 -

: ,-

''I

It. . . .

i.t- ?)

..

e--- - . ~ . . . _ . . . _ _ _ _ _

!f-

i

i- 22 - i,

..

.

remain stable under SSE conditions. PAEC staff has

reviewed .-r' :end the result acceptable.

Cone'paion1

_Jed on the 'nformaticn and reports submitted by,

the Applicant, the meetings and discussions held bet-

ween PAEC and NPC, the evaluationr of PAEC and its f

consultants, the following conclusions may be made: ;

(1) The vibratory ground motion csncerns

jhave been satisfactorily addre.csed bythe Applicant and the PAEC feels reason-

ably assured that the 0.4g SSE value i

i

would be adequate.

(2) The volcanism issue and the correspond-

ing PAEC requirements on the matter ,,

j are already being attended to by the

Applicant. A report on this is sche- -

,

duled to be submitted to PAEC on Augustr

28, 1979. PAEC shall then evaluate f,

|

this report to dete=mine that:

Ia. Excessive ash fall, glowing

i.

iavalanche and gas accumulation,

as wel.'. as laharic slides, have

been considered in the des'.gn

of the PNPP-1.

1284 038.

o

P

O . m

. _ _ _ . . _ _. _ .. . _ _ _ ___- . . . . . - _.

h

..

.,

-

23 --

b. The volcano surveillance sy. stem

is adequate for the intended

application.

c. Adequate procedures and action i

plan have been established to i'smitigate against a radioactive-

i!

release in the event of an erup- -

ttion of Mt. Natib.

t

(3) The respnse to the foundation engineer-

ing concerns, particularly on shear I

moduli and " strain softening", and the -

t

cut and natural slope stability appear :

I

adequate and acceptable. With respect i

to the analysis of topographical and.

local effects, considering the present'

',

i

state of the art, the WIPCO indication|

that methods used meet USNRC criteria '

-

i

and the conservatisms employed in the |

| fcalculations, PAEC feels that the erstat- I

',

tment of the issue is reasonable andacceptable. t,

& r', s ;lim O D. ISE

'

jCommissicner ,

1284 139-

Fi

|..

. . .

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. i*

-. .g ;

- ---_24_ ,

.

.-

.

References - i

1. Bolt, B.A., "The Revision of Earthquake Epicenters,LFocal Depths and Origin-Times Using a High Speed

Computer", Geophysical Journal, Royal Astronomical y

Society, 3, p. 433-440, 1960.i' >

2. J. R. Murphy and L. J. O'Brien, " Analysis of a ,,

Worldwide Strong Motion Data Sample to Develop p t'!'and Improved Correlation Between Peak Acceleration, }

Seismic Intensity and Other Physical Parameters", i p-

US Nuclear Regulatory Commission Report NUREG 0402, p,

January, 1976. t

*3. H. Rood, et al. " Report on TVA Seismic Issue by E.

NRC Staff Working Group", Unpublished US Nuclear g

Regulatory Ccmmission Report, May 1978. k

>&

1284 940 |

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- g.

eI =

3e=M

:

iPF9-

:| g'i:b'G'I

li'$!j r '

t',

.

>

.. . .

,

i~~

---

e- mw

'.

.r r. TABLE 1 -

.

REFERENCE MATERIALS PROVIDED TO THE IAEA SAFETYMISSION ON GEOLOGIC HAZARDS AND GEOTECHNICAL ,

ASPECTS OF PNPP-1 -

1. PNPP-1 Preliminary Safety Analysis Report (especially Chap- '

ters 2 & 3 en Site Characteristics and on Design of Struc-tures, Components, Equipment and Systems; 8 volumes) July197,. I i

2. PNPP-1 PSAR Amendment No. 3 and Amendment 3 Information hShest. (Undated but prepared in 1978)

3. Site Confirmation Report, January 1976 '

; ,

4. Engineering Report No. 1, February 1976 |'

5. Addendum to Engineering Report No. 1, no date i b

6. Engineering Report No. 2, April 1976

7. Addendum to Engineering Report No. 2, Vibratory Ground Mo- '

tion, May 10 6 f'

8. Engineering Report No. 3, (2 volumes), September 1976 i! r

9. Engineering Report No. 4,. February 1977 EF10. Engineering Report No. 5, May 1978 1

11. Responses to PAEC Letter Dated 20, December 1976, no date ~

, c.-12. Respons'es to PAEC Letter Dated 21 May 1977, no date (unbound) E

i ::

13. Geologic Hazards of PNPP Unit 1, July 1977 5--

14. PNPP-1 Volcanic-Seismic Surveillance Program, no date "

15. Seismic Risk Analysis for PNPP-1, no date

16. Geology of Unit 1 Excavation, February 1978

17. Seismic Analysis of PNPP-1, WCAP-9187, February 1978 ,,

18.'PNPP-1 Additional Safety Related Data, 30 June ' '8 k:519. Siegraphical Data of Persennel, no date, unbound et,.

.i L

1284 041 ,!~

,

I6

I

I.

,.1 .

._ _ . . _ . - ___ .. . _ . , . . . . . _ _ , . _ . -

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