50632 Federal Register / Vol. 62, No. 187 / Friday, September 26, 1997 / Notices

1 In his e-mail dated March 26, 1997,

supplementing his Petition, the Petitioner also

requested removal of ‘‘all spent fuel out of the

southern California seismic zone.’’

2By letter dated June 26, 1997, the NRC staff

advised the Petitioner that his e-mail dated April

25, 1997, concerning the ability of the SONGS

steam generators to withstand a major seismic

event, would be treated as a separate 10 CFR 2.206

Petition.

3See 10 CFR Part 50, Appendix A, Criterion 2 and

10 CFR 50.34(a)(1)(i); see also 10 CFR Part 100,

Appendix A, V.(a) which provides, in part, that

‘‘the design of each nuclear power plant shall take

into account the potential effects of vibratory

ground motion caused by earthquakes.’’ The

investigative obligations of 10 CFR Part 100,

Appendix A, which are only imposed explicitly on

applicants for construction permits, were effective

December 13, 1973 (38 FR 31279, November 13,

1973). The Licensing Board issued its decision

regarding the SONGS Units 2 and 3 construction

permits on October 15, 1973. However, the SONGS

site was reviewed against the Appendix A criteria

during the construction permit licensing review

which was updated at the operating license review

stage.

4The SSE is defined, in part, as ‘‘that earthquake

which is based upon an evaluation of the maximum

earthquake potential considering the regional and

local geology and seismology and specific

characteristics of local subsurface material. It is that

earthquake which produces the maximum vibratory

ground motion for which certain structures,

systems, and components are designed to remain

functional.’’ See 10 CFR Part 100, Appendix A.

III.(c).

Alternative Use of Resources

This action does not involve the use

of any resources not previously

considered in the Final Environmental

Statement, Supplement No 1, for WBN

Units 1 and 2, dated April 1995.

Agencies and Persons Consulted

In accordance with its stated policy,

on August 21, 1997 the staff consulted

with the Tennessee State official, Mr. J.

Graves of the Division of Radiological

Health, regarding the environmental

impact of the proposed action. The State

official had no comments.

Finding of No Significant Impact

Based upon this environmental

assessment, the Commission concludes

that the proposed action will not have

a significant effect on the quality of the

human environment. Accordingly, the

Commission has determined not to

prepare an environmental impact

statement for the proposed action.

For further details with respect to the

proposed action, see the licensee’s letter

dated June 20, 1997, which is available

for public inspection at the

Commission’s Public Document Room,

the Gelman Building, 2120 L Street,

NW., Washington, DC, and at the local

public document room located at the

Chattanooga-Hamilton County Library,

1001 Broad Street, Chattanooga,

Tennessee.

Dated at Rockville, Maryland, this 22nd

day of September 1997.

For the Nuclear Regulatory Commission.

Frederick J. Hebdon,

Director, Project Directorate II–3, Division of

Reactor Projects—I/II.

[FR Doc. 97–25631 Filed 9–25–97; 8:45 am]

BILLING CODE 7590–01–P

NUCLEAR REGULATORY

COMMISSION

[Docket Nos. 50–361 and 50–362]

Southern California Edison Company,

Et Al., San Onofre Nuclear Generating

Station, Units 2 and 3; Issuance of

Director’s Decision Under 10 CFR

2.206

Notice is hereby given that the

Director, Office of Nuclear Reactor

Regulation, has acted on a Petition for

action under 10 CFR 2.206 received

from Mr. Stephen Dwyer dated

September 22, 1996, as supplemented

by letter dated December 10, 1996, two

e-mails of March 26, 1997, and an email of May 28, 1997, for the San Onofre

Nuclear Generating Station (SONGS),

Units 2 and 3.

The Petition requests that the

Commission shut down the San Onofre

Nuclear Generating Station pending a

complete review of the ‘‘new seismic

risk.’’ As a basis for the request, the

Petitioner asserts that a design criterion

for the plant, which was ‘‘0.75 G’s

acceleration,’’ is ‘‘fatally flawed’’ on the

basis of the new information gathered at

the Landers and Northridge quakes. The

Petitioner asserts (1) that the

accelerations recorded at Northridge

exceeded ‘‘1.8 G’s and it was only a

Richter 7+ quake,’’ (2) that there were

horizontal offsets of up to 20 feet in the

Landers quake, and (3) that the

Northridge fault was a ‘‘Blind Thrust

and not mapped or assessed.’’

The Director of the Office of Nuclear

Reactor Regulation has determined that

the request should be denied for the

reasons stated in the ‘‘Director’s

Decision Under 10 CFR 2.206’’ (DD–97–

23), the complete text of which follows

this notice and which is available for

public inspection at the Commission’s

Public Document Room, the Gelman

Building, 2120 L Street, N.W.,

Washington, D.C. 20555, and at the

Local Public Document Room located at

the Main Library, University of

California, P. O. Box 19557, Irvine,

California 92713.

Dated at Rockville, Maryland, this 19th day

of September 1997.

For the Nuclear Regulatory Commission.

Samuel J. Collins,

Director, Office of Nuclear Reactor

Regulation.

Director’s Decision Under 10 CFR 2.206

I. Introduction

By Petition dated September 22, 1996,

Stephen Dwyer (Petitioner) requested

that the Nuclear Regulatory Commission

(NRC) take action with regard to San

Onofre Nuclear Generating Station

(SONGS). The Petitioner requested that

the NRC shut down the SONGS facility

‘‘as soon as possible’’ pending a

complete review of the ‘‘new seismic

risk.’’ 1 The Petitioner asserted as a basis

for this request that a design criterion

for the plant, which was ‘‘0.75 G’s

acceleration,’’ is ‘‘fatally flawed’’ on the

basis of new information gathered at the

Landers and Northridge earthquakes.

The Petitioner asserted (1) That the

accelerations recorded at Northridge

exceeded ‘‘1.8G’s and it was only a

Richter 7+ quake,’’ (2) that there were

horizontal offsets of up to 20 feet in the

Landers quake, and (3) that the

Northridge fault was a ‘‘Blind Thrust

and not mapped or assessed.’’ On

November 22, 1996, the NRC staff

acknowledged receipt of the Petition as

a request pursuant to 10 CFR 2.206 and

informed the Petitioner that there was

insufficient evidence to conclude that

the requested immediate action was

warranted. Notice of the receipt of the

Petition indicating that a final decision

with respect to the requested action

would be forthcoming at a later date was

published in the Federal Register on

November 29, 1996 (61 FR 60734).

The Petitioner provided supplemental

information in support of his Petition in

a letter dated December 10, 1996, two emails dated March 26, 1997, and an email dated May 28, 1997.2 My Decision

in this matter follows.

II. Discussion

A. Regulatory Requirements Associated

With Potential Earthquake Motion and

the Licensing Basis for SONGS

The design bases for each nuclear

power plant must take into account the

potential effects of earthquake ground

motion.3 The seismic design basis,

called the safe-shutdown earthquake

(SSE), defines the maximum ground

motion that certain structures, systems,

and components necessary for safe

shutdown are designed to withstand.4

SONGS Units 2 and 3 seismic design

basis is consistent with the siting

criteria set forth in Title 10 of the Code

of Federal Regulations, Part 100,

Appendix A, ‘‘Seismic and Geologic

Siting Criteria for Nuclear Power

Plants.’’ Appendix A describes the

nature of the investigations required to
Federal Register / Vol. 62, No. 187 / Friday, September 26, 1997 / Notices 50633

5See 10 CFR Part 100, Appendix A. IV.

6A capable fault is a fault which has exhibited

one or more of the following characteristics: (1)

Movement at or near the ground surface at least

once within the past 35,000 years or movement of

a recurring nature within the past 500,000 years, (2)

Macro-seismicity instrumentally determined with

records of sufficient precision to demonstrate a

direct relationship with the fault, and (3) A

structural relationship to a capable fault according

to characteristics (1) or (2), above, such that

movement on one could be reasonably expected to

be accompanied by movement on the other. See 10

CFR Part 100, Appendix A.III(g).

7The findings of these investigations were

reviewed extensively by the staff and were litigated

in proceedings concerning the issuance of the

construction permit and operating licenses for

SONGS Units 2 and 3. See LBP–73–36, 6 AEC 929

(1973); ALAB–248, 8 AEC 957 (1974) and see LBP–

82–3, 15 NRC 61 (1982); ALAB–673, 15 NRC 688

(1982); ALAB–717, 17 NRC 346 (1983); and see

Carstens v. NRC 742 F.2d 1546 (D.C. Cir. 1984),

cert. denied, 471 U.S. 1136 (1985) (the Court of

Appeals affirmed the Commission’s granting of the

operating licenses for SONGS Units 2 and 3, noting

the voluminous record and substantial evidence

supporting the seismic review).

8 In 1935, Charles Richter introduced the concept

of magnitude to describe the size of earthquakes.

His original formula was based on events in

southern California recorded on torsion

seismographs within 600 km of the epicenter. This

is the magnitude labeled ML. Over the years Richter

and others developed formulas to compute

magnitudes from body and surface waves (mb and

MS) at distant (teleseismic) stations as well as other

methods to compute magnitudes for local events in

other areas of the world. Most of these methods of

computing magnitude use as the measured variable

the amplitude of one or more seismic waves. All of

these magnitude procedures, including the moment

magnitude MW, have been developed to produce a

number which represents the size of an earthquake,

and each was shingled onto Richter’s original

procedure so that the formulas would produce

similar values at particular places on the magnitude

scale. Each computation procedure has its own

magnitude or distance range over which it is valid.

Surface wave magnitude is normally calculated

from the amplitudes of waves with periods near 20

seconds. Moment magnitude is based on the

seismic moment. Seismic moment is calculated

from recordings on digital seismographs and

compared to the waveforms synthetic seismograms

from numerical models of the fault rupture to

determine the moment.

9See cases cited supra note 7.

10See response to Generic Letter 88–20,

Supplement 4, Individual Plant Examination of

External Events (IPEEE) dated December 15, 1995,

discussed, infra, at pages 22–24.

obtain the geologic and seismic

information necessary to determine site

suitability and provide reasonable

assurance that a nuclear power plant

can be constructed and operated at a site

without undue risk to health and safety

of the public. Among other particulars,

Appendix A requires 5—

• Determination of the lithologic,

stratigraphic, hydrologic, and structural

geologic conditions of the site and the

region surrounding the site.

• Identification and evaluation of

tectonic structures underlying the site

and the region surrounding the site,

whether buried or expressed at the

surface.

• Evaluation of physical evidence

concerning the behavior during prior

earthquakes of the surficial geologic

materials and substrata underlying the

site.

• Determination of the static and

dynamic engineering properties of the

materials underlying the site, such as

seismic wave velocities, density, water

content, porosity, and strength.

• Listing of all historically reported

earthquakes that affected or that could

reasonably be expected to have affected

the site.

• Correlation of epicenters of

historically reported earthquakes, where

possible, with tectonic structures, any

part of which is located within 320

kilometers (200 miles) of the site.

Epicenters that cannot be correlated

with tectonic structures shall be

identified with tectonic provinces, any

part of which is located within 320

kilometers (200 miles) of the site.

• For capable faults 6 that may be of

significance in establishing the SSE or

that are longer than 330 meters (1000

feet) and within 8 kilometers (5 miles)

of the site, determination of the length

of the fault; the relationship of the fault

to the regional tectonics structures; and

the nature, amount, and geologic history

of displacements along the fault,

including the estimated amount of

maximum Quaternary displacement

related to any one earthquake along the

fault are required.

The information collected in these

investigations is used to determine the

vibratory ground motion at the site,

assuming that the epicenters of the

earthquakes are situated at the point on

the tectonic structures or in the tectonic

provinces nearest to the site. The

earthquake that could cause the

maximum vibratory ground motion at

the site is designated the SSE. The

vibratory ground motion produced by

the SSE is defined by response spectra,

which are smoothed design spectra

developed from a set of vibratory

ground motions caused by more than

one earthquake.

SONGS was licensed consistent with

the seismic and geologic siting criteria

for nuclear power plants set forth in 10

CFR Part 100, Appendix A, described

above. The site has undergone geologic,

geophysical, geotechnical, and seismic

investigations and reviews that are at

least as thorough and comprehensive as

those of any critical facility.7 The

SONGS SSE is based on the assumed

occurrence of a surface-wave (MS) 8

magnitude 7 earthquake on the offshore

zone of deformation (OZD), a right

lateral strike slip fault zone,

approximately 8 kilometers from the site

at its closest approach. This magnitude

7 event is larger than any earthquake

known to have occurred on the OZD,

and the resulting ground motion

estimate is larger than that which could

reasonably be expected at the SONGS

site from any other seismic source. The

determination of the SSE was made in

accordance with the criteria and

procedures specified in Appendix A to

10 CFR Part 100 and using a multiple

hypothesis approach in which several

different methods were used to

determine each parameter; sensitivity

studies were performed to account for

the uncertainties in the earth sciences.

In addition, the plant has design

margins (capability) well beyond the

demands of the SSE. The ability of a

nuclear power plant to resist the forces

generated by the ground motion during

an earthquake is thoroughly

incorporated in the design and

construction of the plant. The codes that

govern the construction of residential

and commercial buildings are far less

stringent than the requirements for

nuclear power plants. As a result,

nuclear power plants are able to resist

earthquake ground motions well beyond

their design basis, the SSE, and far

above the ground motion that would

result in damage to buildings designed

and built to commercial codes.

The geologic and seismic siting and

the design of SONGS were reviewed by

the NRC staff, the U. S. Geologic Survey,

the National Oceanic and Atmospheric

Administration, the Advisory

Committee on Reactor Safeguards and

were litigated before the Atomic Safety

Licensing Board before they were

licensed by the Commission.9 The NRC

continually monitors the adequacy of

the design of nuclear power plants in

order to protect the public health and

safety. The SONGS licensee performed

an individual plant examination of

external events (IPEEE).10 The IPEEE is

a program that involves the evaluation

of the capability of a nuclear power

plant to withstand the effects of several

natural phenomena such as earthquakes,

fires, and floods, well beyond its design

bases. The most recent geologic and

seismic information for the southern

California region was used in the

probabilistic analysis to quantify the

seismic hazard and the uncertainties for

the SONGS site for this program.

The ground motion from an

earthquake at a particular site is a

function of the magnitude and focal

mechanism (type of faulting, i.e.,

normal, reverse, strike slip) at the

earthquake source. It is also a function

of the distance of the facility from the
50634 Federal Register / Vol. 62, No. 187 / Friday, September 26, 1997 / Notices

11Standard Review Plan (SRP) is used as

guidance for the Office of Nuclear Reactor

Regulation staff responsible for the review of

applications to construct and operate nuclear power

plants.

12N. A. Abrahamson and W. J. Silva, ‘‘Empirical

Response Spectral Attenuation Relations for

Shallow Crustal Earthquakes,’’ Seismological

Research Letters, 68, 94–127 (1997); David M.

Boore, William B. Joyner, and Thomas E. Fumal,

‘‘Equations for Estimating Horizontal Response

Spectra and Peak Acceleration From Western North

American Earthquakes: A Summary of Recent

Work,’’ Seismological Research Letters, 68, 128–153

(1997); K. W. Campbell, ‘‘Empirical Near-Source

Attentuation Relationships for Horizontal and

Vertical Components of Peak Ground Acceleration,

Peak Groud Velocity and Pseudo-Absolute

Aceleration Response Spectra,’’ Seismological

Research Letters, 68, 154–179; K. Sadigh, C.Y.

Chang, J. A. Egan, F. Makdisi, and R. R. Yongs,

‘‘Attentuation Relationships for Shallow Crustal

Earthquakes Based on California Strong Motion

Data,’’ Seismological Research Letters, 68 180–189

(1997).

13Thorne Lay and Terry C. Wallace, Modern

Global Seismology, Academic Press, Inc., San

Diego, California; K. W. Campbell (1995).

14Stephen Dwyer, Letter to Dr. Shirley Jackson

and Frank J. Miraglia, Jr., with enclosure, dated

December 10, 1996.

15Mark D. Petersen, Chris H. Cramer, William A.

Bryant, Michael S. Reichle, and Tousson R.

Toppozada, ‘‘Preliminary Seismic Hazard

Assessment for Los Angeles, Ventura, and Orange

Counties, California, Affected by the 17 January

1994 Northridge Earthquake,’’ Bulletin of the

Seismological Society of America, 86, S247–S261

(1996).

16 Id.

17 Id.

18Stephen Dwyer, e-mail message to Dr. Jackson,

Subject: San Onofre Nuclear Power Plant Risk,

dated September 22, 1996.

19Abrahamson and Silva, supra note 12.

fault and the geology immediately under

the facility site. The estimates of SSE

ground motion for the SONGS site

conform with the procedures and

criteria specified in 10 CFR Part 100,

Appendix A and the Standard Review

Plan (SRP) 11 Sections 2.5.1 and 2.5.2

(NUREG–0800). As previously stated,

the earthquake that was determined to

control the design of SONGS is a MS=7

located on the OZD at a distance of 8

kilometers from the site. The

appropriate level of conservatism for

characterizing the ground motion

through a site-specific spectrum as

specified in SRP 2.5.2 is the 84th

percentile. This level of conservatism

was used in the design and licensing

review of SONGS, Units 2 and 3.

Since the SONGS plants were

licensed, a new magnitude scale,

moment magnitude (MW), has come into

common usage. The most recently

published ground motion attenuation

relationships 12 use MW. An attenuation

relationship is a relationship between

sized earthquake, distance to fault and

the amplitude of the ground motion.

Since magnitude 7 MW is equal to

magnitude 7 MS,13 there is no need to

make a conversion between MW and MS

when comparing the ground motion

estimates obtained using the recent

attenuation relationships to the SONGS

SSE ground motion.

B. Responses to the Petitioner’s

Concerns

1. Concern that SONGS is in a High

Seismic Hazard Area

In the enclosure to his letter,14 the

Petitioner referenced ‘‘a recent paper by

M. D. Petersen et al. (Seismic Hazard

Analysis, AEG, 1–20–96)’’ and stated

that it concludes that the entire Los

Angeles, Ventura, and Orange Counties

are high hazard areas. The Petitioner

stated that the paper also concludes that

accelerations of 0.4g (pga), 1.0g (0.3-sec

SA), and 0.5g (1-sec SA) can occur

nearly everywhere.

The NRC staff attempted to find the

reference mentioned by Mr. Dwyer but

was unsuccessful. Mark D. Petersen of

the California Division of Mines and

Geology informed the staff that the

correct reference is an article that he

and his coauthors published in the

Bulletin of the Seismological Society of

America.15 Dr. Petersen made a

presentation at a workshop on seismic

hazard in southern California in January

1996 and gave participants in the

workshop preprints and reprints of

some of his recent publications. The

cited reference was one of these

handouts.

In the section of the paper entitled

‘‘Hazard Maps,’’ the authors state:

The DMG probabilistic seismic hazard

maps (10% exceedance in 50 years) for peak

ground acceleration (pga) and 5% damped

spectral acceleration (SA) at 0.3-and 1-sec

periods on alluvial site conditions are shown

in Figures 3 through 5. These maps may be

useful in characterizing regional variations in

seismic hazard in southern California but

should not be used as input for detailed sitespecific estimates of ground shaking in the

earthquake-resistant design of individual

structures.16

The paper then states—

The three maps show similar hazard

patterns that indicate high hazard over the

entire tri-county area. The expected peak

accelerations exceed 0.4g (pga), 1.0g (0.3 s

SA), and 0.5g (1 s SA) nearly everywhere in

the tri-county area.’’ 17

To address the acceleration values

mentioned by the Petitioner with

respect to SONGS, the NRC staff has

produced Figure 1, which contains a

plot of the SONGS SSE seismic response

spectrum at 5 percent of critical

damping and the values quoted from the

Petersen paper. Since period in seconds

is the reciprocal of frequency in Hertz,

the 1-second period spectral

acceleration (0.5g) is plotted at a

frequency of 1 Hertz, the 0.3-second

period acceleration (1.0g) is plotted at a

frequency of 3.33 Hertz and the peak

ground acceleration (0.4g) is plotted at

a frequency of 33 Hertz. The figure

demonstrates that the spectral

accelerations (accelerations plotted in

the response spectra) used in the design

of SONGS are significantly higher than

those from the Petersen paper, thus

showing the conservatism of the design

basis for SONGS.

2. Concern About a Large Earthquake on

the San Andreas Fault

In the enclosure to his letter dated

December 10, 1996, entitled

‘‘Uncertainty Factors Affecting Seismic

Risk Risk Modelling in Southern

California,’’ the Petitioner stated ‘‘We

must prepare for a great event on the

Southern San Andreas Fault.’’ He also

mentioned an earthquake on the San

Andreas in his e-mail message.18

The NRC staff agrees that there must

be preparation for a large event on the

San Andreas fault and finds that the

SONGS seismic design is well able to

withstand the demands of a large

earthquake on the southern San Andreas

fault. Although the geologic evidence

appears to indicate that the largest event

to have occurred on the southern San

Andreas in the Quaternary Period (the

last 2 million years) is estimated to have

been in the moment magnitude (Mw)

range of 7.5 to 8; to evaluate the

potential ground motion at the SONGS

site from a large earthquake on the

southern San Andreas fault, the staff

made the very conservative assumption

of a moment magnitude 8.25 strike-slip

earthquake at the closest distance of the

San Andreas fault to the site (90

kilometers). This assumption was made

to calculate the effects of a large

earthquake on the San Andreas fault.

The results are plotted in Figure 2

which demonstrates that the design

basis (SSE) spectrum for SONGS is

much higher than the ground motion

estimates from the Mw 8.25 on the San

Andreas fault using four recent

attenuation relationships. These four

empirical attenuation relationships were

developed after the occurrence of the

Northridge and Landers earthquakes,

and include the recent strong ground

motion from these events. They were

performed by internationally known

experts in earthquake ground motion

analysis and were published in the

Seismological Research Letters,19 the

peer-reviewed journal of the

Seismological Society of America. The

assumption of a moment magnitude

8.25 strike-slip earthquake and the
Federal Register / Vol. 62, No. 187 / Friday, September 26, 1997 / Notices 50635

20 Id.

21 J. A. Rial, ‘‘The Anomalous Seismic Response

of the Ground Motion at the Tarzana Hill Site

During the Northridge 1994 Southern California

Earthquake: A Resonant, Sliding Block?’’ Bulletin of

the Seismological Society of America, 86, 1714–

1723 (1996). 22A. M. Shakal, M. Huang, and T. Cao, ‘‘The

Whittier Narrows, California, Earthquake of October

1, 1987: CSMIP Strong Motion Data,’’ Earthquake

Spectra, 4 75–100 (1988). 23R. D. Catchings and W. H. K. Lee, ‘‘Shallow

Velocity Structure and Poisson’s Ratio at the

Tarzana, California Strong-Motion Accelerometer

Site,’’ Bulletin of the Seismological Society of

America, 86 1704–1713; Rial, loc. cit.; Paul

Spudich, Margaret Hellweg, and W. H. K. Lee,

‘‘Directional Topographic Site Response at Tarzana

Observed in Aftershocks of the 1994 Northridge,

California, Earthquake: Implications for Mainshock

Motions,’’ Bulletin of the Seismological Society of

America, 86, S193–S208 (1996).

24Paul Somerville, Chandan Saikia, David Wald,

and Rover Graves, ‘‘Implications of the Northridge

Earthquake for Strong Ground Motions from Thrust

Faults,’’ Bulletin of the Seismological Society of

America, 86 S115–S125 (1996).

25Robert S. Yeats, Kerry Sieh, and Clarence R.

Allen, The Geology of Earthquakes, Oxford

University Press, Oxford, England (1997).

SONGS site foundation geology were

used as input parameters for these four

earthquake ground motion attenuation

relationships.20 The ground motion

estimates were made at the 84th

percentile level recommended by SRP

Section 2.5.2. The plots of the results

obtained from these four attenuation

relationships and the SONGS Units 2

and 3 SSE design response spectrum are

shown in Figure 2. The plotted

information in the figure demonstrates

that the SONGS design is well able to

accommodate the demand of the ground

motion of the large earthquake on the

southern San Andreas fault since it

envelopes the estimates of the four

relationships at all frequencies.

3. Concern About the SONGS Design

Basis in Light of the Landers and

Northridge Earthquakes

In an e-mail message to Chairman

Jackson dated September 22, 1996, the

Petitioner stated—

I am a geologist in Southern California, and

I am deeply concerned by the current

situation at San Onofre NPP. The design

criteria for this old plant was 0.75 G’s

acceleration. With the new information

gathered at the Landers and Northridge

Quakes, this criteria is fatally flawed. The

accelerations recorded at Northridge

exceeded 1.8 G’s !!! and it was only a Richter

7+ quake. Horizontal offsets of up to 20 feet

in the Landers quake were also way beyond

geologists and seismologists estimates. The

whole science is in disarray. Also the

Northridge fault was a ‘‘Blind Thrust’ and not

mapped or assessed. If we have a larger

quake here on the San Andreas, or a smaller

one closer to the plant, well I hate to imagine

* * *. What’s even worse is the fact that

scientists are not able to give us the info we

need to evaluate the situation.

The main points of the Petitioner’s

message appear to be—

• A peak ground acceleration

recorded from the Northridge magnitude

Mw 6.7 earthquake exceeded 1.8 g.

• The Northridge earthquake

occurred on a blind fault that had not

been mapped or assessed.

• The maximum horizontal

displacement of almost 20 feet due to

the Landers magnitude 7.3 earthquake is

much larger than would be estimated.

• Scientists are not able to provide

the information to evaluate the

situation.

The magnitude 6.7 Northridge

earthquake of January 17, 1994,

occurred on a buried thrust fault in the

San Fernando Valley and was similar to

the 1971 San Fernando Valley

earthquake. The distance from this

earthquake epicenter to the SONGS site

is about 130 kilometers (80 miles). The

Northridge earthquake was felt at

SONGS. A free-field seismic instrument

at SONGS recorded a peak ground

acceleration of 0.025g, which is

significantly less than the SSE peak

ground acceleration of 0.67g, thus

indicating that an earthquake in the

epicentral region of Northridge poses no

threat to the plant. The peak ground acceleration of 1.8g

from the Northridge earthquake referred

to by the Petitioner was recorded by the

California Division of Mines and

Geology station in Tarzana. The

anomalous character of the seismic

response at the Tarzana site is well

known.21 The intense shaking at the

Tarzana site is a condition of the site

and is not characteristic of the

Northridge earthquake. This fact is

demonstrated by the unusually strong

ground motion that was also observed

there during the 1987 Whittier Narrows

earthquake 22 and during the aftershocks

following both the Northridge and

Whittier Narrows mainshocks. In

recognition of the unusually high

ground motion recordings at Tarzana,

there have been a number of studies of

this site 23 to try to determine the cause

of the high recordings. These studies

have attributed the high peak ground

accelerations to the site’s specific

geology. The anomalous site effect was

found to be confined to a small area 50

meters in radius around the station;

beyond this area, the ground motion

recordings were down to their normally

expected values. It is, therefore,

inappropriate to rely on data recorded at

the unique Tarzana site to make

judgments about ground motion

estimates at other locations. The

geologic formations under the SONGS

site differ from those at the Tarzana site.

The SONGS site does not anomalously

amplify the earthquake ground motion

as the Tarzana site does. During the

evaluation of the site no geologic

formations under SONGS were

identified that would result in

exceptionally high earthquake ground

motions. Further, recorded earthquakes

at SONGS have not exhibited any

unusual amplifications.

As a result of their studies of the near

field ground motions from thrust faults,

Somerville et al.24 found that the ground

motions from the Northridge

earthquake, in general, are within the

84th percentile when compared to

previously developed empirical

attenuation relations for thrust faults.

This finding indicates that the

Northridge ground motion data would

not cause seismologists to revise ground

motion estimates for thrust fault

earthquakes. The data from this

earthquake have been incorporated into

the strong ground motion databases and

have not significantly altered the results

of the attenuation relationships. In

addition, it is inappropriate to use the

ground motions from thrust faults for

estimates in a region in which there is

no potential for this type of faulting,

such as the South Coast Borderland

where SONGS is located.

To address the issue of whether there

is a potential for buried thrust faults at

the SONGS site, the staff referred to a

book by Yeats et al.25 that contains a list

and a map of the regions of the world

that have the potential for large reversefault earthquakes. Thrust faults are low

angle reverse faults. In California, the

regions listed are the northern California

coast, the Coast Ranges of central

California, and the western Transverse

Ranges. The 1994 Northridge earthquake

and the 1971 San Fernando Valley

earthquake are related to the western

Transverse Ranges. There is no

indication of reverse-fault earthquakes

in the South Coast Borderland where

SONGS is located.

In southern California, the mountain

ranges flanking the ‘‘Big Bend’’ of the

San Andreas fault (the Transverse

Ranges) strike east-west and are

bounded on the south by north-dipping

range-front reverse faults, part of a

discontinuous system of faults that

extends from the Santa Barbara Channel

eastward to the eastern end of the San

Gabriel Mountains. Other important

reverse faults in this region include the

Pleito fault in the southern margin of

the South San Joaquin Basin; the southdipping Oak Ridge fault in the Ventura

Basin which extends eastward to the

San Fernando Valley as a blind thrust

that produced the 1994 Northridge
50636 Federal Register / Vol. 62, No. 187 / Friday, September 26, 1997 / Notices

26 Id.

27Mark D. Peterson, et al., supra note 15.

28F.F. Vickery, ‘‘The Interpretation of the

Physiography of the Los Angeles Coastal Belt,’’

Bulletin of the American Association of Petroleum

Geologists, 11, 417–424 (1927).

29M.L. Zoback and R.E. Anderson, ‘‘Cenozoic

Evolution of the State of Stress and Style of

Tectonism in Western United States,’’ Philosophical

Transactions of the Royal Society of London, 300,

407–434 (1981); R. Weldon and E. Humphreys, ‘‘A

Kinematic Model of Southern California,’’

Tectonics, 5, 38–48 (1986); D.F. Argus and R.G.

Gordon, ‘‘Sierra Nevada-North America Motion

From VLBI and Paleomagnetic Data—Implications

for the Kinematics of the Basin and Range, Colorado

Plateau, and California Coast Ranges,’’ EOS

Transactions, American Geophysical Union, 69,

1418 (1988); R.S. Stein and R.S. Yeats, ‘‘Hidden

Earthquakes,’’ Scientific American, 260, 48–57

(1989).

30Stein and Yeats, supra notes 25 and 29.

31 D.T. Barrie, T. Totnall, and E. Gath,

‘‘Neotectonic Uplift and Ages of Pleistocene Marine

Terraces, San Joaquin Hills, Orange County,

California,’’ in E.G. Heath and W.L. Lewis (editors),

The Regressive Pleistocene Shoreline Coastal

Southern California, South Coast Geological

Society, Inc., 1992 Annual Field Trip Guide Book

No. 20, 115–122 (1992).

32 K.R Lajoie, D.J. Ponti, C.L. Powell, II, S.A.

Mathieson, and A.M. Sarna-Wojcicki, ‘‘Emergent

Marine Strandlines and Associated Sediments,

Coastal California; a Record of Quaternary SeaLevel Fluctuations, Vertical Tectonic Movements,

Climatic Changes, and Coastal Processes,’’ in E.G.

Heath and W.L. Lewis (editors), The Regressive

Pleistocene Shoreline Coastal Southern California,

South Coast Geological Society, Inc., 1992 Annual

Field Trip Guide Book No. 20, 81–104 (1992).

33 Yeats, et al., supra note 25.

34 K.W. Campbell and Y. Bozorgnia, ‘‘Empirical

Analysis of Strong Ground Motion from the 1992

Landers, California, Earthquake,’’ Bulletin of the

Seismological Society of America, 84, 573–588

(1997).

earthquake; and a blind reverse-fault

system beneath the Santa Monica

Mountains North of the Los Angeles

basin. Major earthquakes generated by

these reverse faults include the 1952

Kern County earthquake in the South

San Joaquin Valley (MS 7.7), the 1971

San Fernando earthquake at the eastern

edge of the Ventura basin (MW 6.7), the

1978 Santa Barbara earthquake in the

western Ventura basin (ML 5.9), the

1987 Whittier Narrows earthquake in

the Los Angeles basin (ML 5.9), the 1991

Sierra Madre earthquake at the southern

edge of the San Gabriel Mountains

northeast of Los Angeles (ML 6.0), and

the 1994 Northridge earthquake in the

San Fernando Valley (ML 6.7). Of these,

only the 1952 and 1971 earthquakes

produced surface rupture. Global

Positioning System satellite geodesy

confirms the high convergence rate as a

result of reverse slip on these faults,26

indicating this is an active thrust fault

area. These indications were not seen in

the SONGS area.

To state that the Northridge

earthquake occurred on a blind fault

that had not been mapped or assessed

is an oversimplification. Blind thrust

faults are recognized as significant

sources of seismic hazard in areas of

active folding, and the Transverse

Ranges-Los Angeles basin has long been

recognized as such an area. If, before the

Northridge earthquake, such a fault had

been sought as part of a siting

investigation, it or the active folding

indicative of such a fault would have

been found and would have been

considered in the seismic hazard

estimate. In addition, the potential

occurrence of a MW 6.5 to 7 on a buried

fault has been assumed in the

commercial design and construction

codes for the area where the Northridge

earthquake occurred, so in effect, the

potential for blind faults has been

accounted for.

The types of site investigations,

borehole drilling, and seismic survey

profiles normally performed for critical

facilities such as nuclear power plants

are not used for normal residential or

commercial structures because of the

high costs of such work. For residences

or commercial buildings, the codes rely

on more generalized hazard estimates,

such as those found in Petersen et al.27

These hazard studies incorporate all the

known geologic information in their

ground motion estimates.

The most promising new data for the

identification of areas of potential

buried thrust faults comes from geodetic

measurements of the satellite-based

Global Positioning System, which is

capable of determining convergence

rates across folded terranes. Geomorphic

studies are important in that the

deformation of late Quaternary stream

or coastal terraces provides quantitative

data on the uplift rates or lack of uplift

of postulated active folds over buried

faults. In fact, the locale of the 1987

Whittier Narrows, California,

earthquake was identified more than 70

years ago 28 as an active anticline on the

basis of warped geomorphic surfaces.

The SONGS site lies in a relatively

stable structural block bounded by

major northwest-southeast trending

strike-slip faults. The relative motion

between the Pacific plate and the North

American plate is accommodated, in

part, by dextral strike slip along the San

Andreas fault system and faults in the

borderlands, extension in the Gulf of

California, and contraction in the

Transverse Ranges and the Los Angeles

basin region.29

The tectonic setting of the SONGS site

is significantly different from the

complex regime of the Transverse

Ranges and the Los Angeles basin. This

difference is reflected in the higher

seismicity in the Transverse Range and

the Los Angeles basin than in the

SONGS site area. The presence or

absence of blind thrust faults in a region

is indicated by the presence or absence

of significant uplift and folding of late

Quaternary period deposits and

geomorphic surfaces 30 as evidenced in

the Transverse Ranges and the Los

Angeles basin region. Mapping of

marine terraces along the western flank

of the San Joaquin Hills to the north of

the SONGS site indicates a uniform

uplift rate for the past 80 to 120

thousand years.31 Lajoie et al.32 reported

on the coastal region between San

Onofre Bluff and Torrey Pines north of

Soledad Mountain in San Diego and

noted that there has been no significant

crustal tilt perpendicular to the

coastline during much of the Quaternary

Period. There is also no indication from

the marine terrace studies of significant

tilt parallel to the coastline during much

of the Quaternary Period. The marine

terrace data, along with other geological

mapping and geophysical surveys, have

not identified geologically young folds

or blind thrust faults in the SONGS site

vicinity. The closest capable fault to the

site is the OZD 8 kilometers from the

site, and it is the postulated earthquake

on this fault that dominates the seismic

hazard at SONGS. Therefore, the

statement that the Northridge

earthquake occurred on a blind fault

that had not been mapped or assessed,

and the implication that such a

condition could also exist at the SONGS

site, are not valid.

The Landers magnitude MW 7.3

earthquake of June 28, 1992, was in the

Eastern California Shear Zone (ECSZ)

approximately 140 kilometers from the

SONGS site. The ECSZ is a complex

zone of predominantly right lateral

strike-slip faulting. The earthquake was

caused by strike-slip faulting on five

fault segments with a total rupture

length of about 70 kilometers.33

Campbell and Bozorgnia 34 used 167

accelerograms recorded during the

Landers earthquake to study the ground

motions from this event. A comparison

of these recordings with ground motions

predicted by contemporary attenuation

relationships indicated that

relationships developed before the

Landers earthquake made a reasonable

prediction of the Landers ground

motions within 60 kilometers of the

fault, and relationships developed after
Federal Register / Vol. 62, No. 187 / Friday, September 26, 1997 / Notices 50637

35Carlos Lazarte, Jonathan D. Bray, Arvid M.

Johnson, and Robert E. Lemmer, ‘‘Surface Breakage

of the 1992 Landers Earthquake and Its Effects on

Structures,’’ Bulletin of the Seismological Society of

America, 84, 547–561 (1994). 36 Donald L. Wells and Kevin J. Coppersmith,

‘‘New Empirical Relationships Among Magnitude,

Rupture Length, Rupture Width, Rupture Area, and

Surface Displacement,’’ Bulletin of the

Seismological Society of America, 84, 974–1002

(1994).

37 David P. Schwartz. Personal communication

with Dr. Robert Rothman, of the NRC staff, June

1997. Dr. Schwartz is a senior geologist employed

by the U.S. Geological Survey in Menlo Park,

California and a international authority on

paleoseismology.

38Bulletin of the Seismological Society of

America, Volume 86, Number 1, Part B

Supplement, February 1996.

39Bulletin of the Seismological Society of

America, Volume 84, Number 3, June 1994.

40List of Seismic Analysis Uncertainties: (1) How

to quantify slip rates and maximum magnitudes

along with their uncertainties for all fault sources.

(2) How to incorporate blind thrusts with

appropriate weighting. (3) What seismogenic zone

widths to use for various fault zones. (4) Which

magnitude distributions are most appropriate for

various faults. (5) How to incorporate background

seismicity and which ‘‘b’’ value is most appropriate

for exponentially distributed earthquakes. (6)

Whether to use source zones or simple point

sources in modelling background seismicity. (7)

Which alternative segmentation models are viable

(including alternative cascades models for ‘‘A’’

zones). (8) How to incorporate geodetic data

directly in the model. (9) Which attenuation

relations are most appropriate and how to model

ground motion from large (M>8) earthquakes. (10)

How to resolve the discrepancy between the rate of

earthquakes in this and other seismic hazard

models and the historic earthquake record

(especially in the Transverse Ranges).

41Peterson, et al., supra note 15.

the Landers earthquake did a reasonably

good job of predicting the Landers

ground motions within the distance

ranges for which they were applicable.

This information shows that there was

nothing extraordinary about the ground

motions from the Landers earthquake

that would challenge the adequacy of

the near field ground motion estimates

made for the SONGS SSE. To

demonstrate the adequacy of the SONGS

SSE ground motion, Figure 3 contains a

plot of the SSE response spectrum and

the 84th percentile response spectra

obtained from the four recent

earthquake ground motion attenuation

relationships to estimate the ground

motion for a magnitude MW 7

earthquake at a distance of 8 kilometers.

The SONGS response spectrum

envelopes the response spectra of all

four relationships at all frequencies. To address the issue of the 20 feet (6

meters) of fault displacement as a result

of the Landers earthquake, the staff has

reviewed the work of researchers on this

subject. Post-earthquake investigations

have found that slip on the Landers

earthquake faults was extremely

heterogeneous both along strike and

down dip. The magnitude of the

horizontal offset varied along the fault

trace, but was typically 2 to 3 meters

with maximum strike-slip offset of

about 6 meters.35 This offset is not

unusual and is within the range of

offsets for an earthquake of this size.36

The U.S. Geological Survey, with NRC

sponsorship, has conducted

paleoseismic studies of the fault

segments that ruptured during the

Landers earthquake. Trenches across the

faults provide clear evidence of the two

most recent pre-1992 surface faulting

events. The most recent faulting,

Holocene age, has displacements

essentially the same as the 1992 event.

Evidence from the trenches also

indicates that the segments that

ruptured during the 1992 event had

ruptured during the previous events.37

If, before the Landers earthquake, these

faults had been subjected to the type of

investigations that nuclear power plant

sites undergo, the earthquake and fault

rupture potential would have been

identified.

There are no faults at the SONGS site

capable of surface offset. The fault

nearest to the SONGS site capable of

significant surface offset is the OZD,

which is 8 kilometers from the site.

Assuming that there were to be offsets

on the order of 6 meters or more on the

OZD, they would have no detrimental

effect on SONGS because of the distance

of the fault, the orientation of the fault,

and the potential ground motion to

which the plant is designed. With respect to the Petitioner’s

statement that scientists are not able to

provide the information to evaluate the

situation, the staff notes that numerous

papers have been published in the

scientific literature and presentations

made at national and international

scientific meetings on these two

earthquakes. In addition, the

Seismological Society of America has

devoted one issue of its Bulletin 38 to the

Northridge earthquake and another

issue to the Landers earthquake.39 The

information about these events is

understood and is widely distributed in

the professional community.

4. Concern About ‘‘Seismic Analysis

Uncertainties’’

In the enclosure to his letter dated

December 10, 1996, the Petitioner

provided a list of 10 seismic analysis

uncertainties 40 and implies that these

must be addressed because new

surprises will occur with each event. The Petitioner appears to have

compiled a list of uncertainties in

estimating seismic hazard from the

Petersen paper.41 There is nothing

unique about this list. These are the

types of issues a geologist or a

seismologist performing earthquake

hazard investigations must routinely

confront. They are among the points

that the NRC Seismic and Geologic

Siting Criteria for Nuclear Power Plants

and the NRC SRP were developed to

address.

The geologic and seismic

investigations and reviews that were

performed for the licensing of SONGS

Units 2 and 3 were deterministic in

nature. In the deterministic method, the

uncertainties were not explicitly

quantified. Rather, a multi-method

approach with sensitivity studies was

used. For instance, to determine the

maximum magnitude estimate for a fault

empirical relationship, such as

magnitude as a function of the

parameters slip rate, the fault length, the

rupture length per event, the rupture

area, and the historical seismicity were

used. Also, various fault segmentation

models were used in magnitude

estimates. To determine the ground

motion from a magnitude 7 earthquake

at a distance of 8 kilometers, attenuation

relationships from the statistical

analysis of empirical ground motion

data, theoretical numerical modeling

studies, and the response spectra from

magnitude 6.5 and larger earthquakes

recorded at distances of 13 kilometers

and less were used. The SSE for the

SONGS site enveloped all of these

estimates. The geology in the site region

was investigated by geologic mapping,

excavation of faults, offshore and

onshore seismic reflection profiles,

onshore refraction profiles, geophysical

surveys, drill holes, well logs, trenching,

geomorphic surveys, and geodetic

studies. The information from these

various studies was analyzed by

experienced professional geologists and

geophysicists, and the site

characteristics were thus developed in a

conservative manner. Independent

studies and reviews were performed by

the NRC staff, the U.S. Geologic Survey,

the National Oceanic and Atmospheric

Adminstration, and the Advisory

Committee on Reactor Safeguards.

These studies and reviews confirmed

the licensee’s determinations.

The uncertainties in seismic hazard

estimates can be addressed

quantitatively through a probabilistic

seismic hazard analysis. In 1991, the

NRC issued Supplement 4 to Generic

Letter 80–20 requesting licensees of

nuclear power plants to perform an

IPEEE to identify plant-specific

vulnerabilities to severe accidents.

Among the events to be assessed were

earthquakes, internal fires, high winds

and tornadoes, external floods, and

transportation and nearby facility

accidents. As part of the SONGS IPEEE
50638 Federal Register / Vol. 62, No. 187 / Friday, September 26, 1997 / Notices

42Risk Engineering, Inc., ‘‘Seismic Hazard at San

Onofre Nuclear Generating Station, ‘‘Prepared for

Southern California Edison Co., Final Report (1995).

43 Id.

44Stephen Dwyer, e-mail message to Dr. Shirley

Jackson, Subject: 2.206 Petition Re: SONGS Seismic

Hazards, dated May 28, 1997.

45FEMA 267, ‘‘Interim Guidelines: Evaluation,

Repair, Modification and Design of Welded Steel

Moment Frame Structures, Program to Reduce the

Earthquake Hazards of Steel Moment Frame

Structures,’’ Federal Emergency Management

Agency, Washington, DC (1995). 46See 10 CFR Part 100, Appendix A, III(d).

program, a state-of-the-art probabilistic

seismic hazard analysis was performed.

In response to an NRC request for

information, Southern California Edison

submitted its contractor’s final report on

the seismic hazard study.42 In the

seismic hazard study, ground motion

exceedance probabilities were

calculated using hypotheses about the

causes and characteristics of

earthquakes in the region. Scientific

uncertainty about the causes of

earthquakes and about the physical

characteristics of potentially active

tectonic features lead to uncertainty in

the inputs to the seismic hazard

calculations. These uncertainties were

quantified using the tectonic

interpretations developed by earth

scientists knowledgeable about the

region. These experts evaluated the

likelihood associated with alternative

tectonic features and with alternative

characteristics of these potential

sources. These and other uncertainties

were propagated through the entire

analysis. The result of the analysis is a

spectrum of hazard curves and their

associated weights. These curves

quantify the seismic hazard at the site

and its uncertainty.

The major components of the

probabilistic seismic hazard analysis are

the identification of the seismic sources,

the determination of the earthquake

magnitude distribution and rate of

occurrence for each source, the

estimation of the ground motion, and

the incorporation of these factors by the

probability analysis into the hazard

curves. The Risk Engineering, Inc.,

report 43 more than adequately

demonstrates how the uncertainties of

the type the Petitioner listed in the

enclosure to his letter were addressed.

The comparison of the probabilistic

seismic hazard results to the SSE

indicates that the SSE response

spectrum has an annual probability of

being exceeded in the range of 5×10¥6

to 4×10¥4, depending on the frequency.

This estimate is similar to the

probabilistic hazard estimates for other

critical facilities in the western United

States. The low frequency of exceedance

of the SSE ground motion provides

further assurance that the licensing

basis for SONGS provides adequate

protection of the health and safety of the

public.

5. Concern About the Failure of WeldedSteel Frames in Commercial Buildings

During the Northridge Earthquake

In an e-mail message to Dr. Shirley

Jackson,44 the Petitioner stated—

The breaking of welds in steel buildings in

the San Fernando Valley is a warning that all

sorts of steel welds and fittings are

vulnerable. The number of such welds and

fittings at SONGS is almost uncountable, and

it’s therefore unrealistic to believe that they

will all be undamaged or broken at forces far

below the Design Basis Event of 67%g.

It appears that the Petitioner is

referring to the failure of welded-steel

moment-resisting frames (WSMFs) in

high-rise residential and commercial

buildings during the 1994 Northridge

earthquake. Following the Northridge

earthquake, inspections of many

otherwise intact buildings indicated

structural damage to WSMFs. The

WSMFs were specifically designed on

the basis of the assumption that they

would be capable of extensive yielding

and plastic deformation. The

deformation was assumed to be

accomplished by the yielding of plastic

hinges in the beams at their connections

to the columns. Damage was expected to

consist of moderate yielding at the

connections and localized buckling of

the steel elements. However, contrary to

the design assumption, the WSMF

failures were brittle fractures with

unanticipated deformations in girders,

cracking in column panel zones, and

fractures in beam-to-column weld

connections. A number of factors related

to seismic analysis and design,

materials, fabrication, and construction

have been identified as contributing to

the failure of the WSMFs and are the

focus of research projects sponsored by

the Federal Emergency Management

Agency.45

The method of computing seismic

loads, their combination with other nonseismic loads, the acceptance criteria,

and the quality assurance requirements

for nuclear power plants are

significantly more conservative than

those for non-nuclear buildings

designed using building codes for

residential or commercial structures.

For nuclear power plants, two levels of

ground motion, based on very

conservative siting criteria, are

determined for designing the safetyrelated structures, systems, and

components. For the lower level of

vibratory motion, the operating-basis

earthquake,46 the load factors, and

acceptable allowable stresses ensure

that the stresses in plant structures

remain at least 40 percent below the

yield stress of the material. For the

higher level vibratory motion, the SSE,

the associated load factors, and

allowable stresses ensure that the

stresses in steel structures do not exceed

the yield stress of the material. The NRC

staff design review guidance specified

in SRP Section 3.7.2 does not accept the

use of inelastic deformation of any steel

member or connection in nuclear power

plants for design-basis seismic events.

Also, the use of broadband design

response spectra, conservatively defined

structural damping values,

consideration of amplified forces at

higher elevations in the plants, and

consideration of all three components of

the design-basis vibratory motion in the

dynamic analysis ensure that the loads

and load paths of the seismic events are

properly considered in the design, as

opposed to the use of static shear forces

in non-nuclear structures. For these

reasons, the failure of WSMFs in

residential and commercial buildings as

a result of the Northridge earthquake is

not relevant to nuclear power plants.

On the basis of its review of the

Petitioner’s request that the SONGS

units be shutdown due to inadequate

protection against potential earthquake

ground motion, the staff has concluded

that the Petitioner has not presented a

basis for such an action.

III. Conclusion

On the basis of the above assessment,

I have concluded that no substantial

health and safety issues have been

raised by the Petitioner that would

require taking the action requested by

the Petitioner. As explained above, the

SONGS site has undergone extensive

geologic, geophysical, geotechnical, and

seismic investigations and reviews,

including a recent analysis to quantify

the seismic hazard and uncertainties for

the SONGS site. Furthermore, SONGS

was licensed consistent with the seismic

and geologic siting criteria for nuclear

power plants set forth in 10 CFR Part

100, Appendix A. The Petitioner has not

provided any information in support of

his concerns and requested actions,

including information regarding recent

earthquakes, which the NRC staff was

not already aware. Accordingly, the

Petitioner’s requested action, pursuant

to Section 2.206, is denied.

A copy of this Decision will be filed

with the Secretary of the Commission
Federal Register / Vol. 62, No. 187 / Friday, September 26, 1997 / Notices 50639

for the Commission to review in

accordance with 10 CFR 2.206(c) of the

Commission’s regulations. As provided

by this regulation, the Decision will

constitute the final action of the

Commission 25 days after issuance,

unless the Commission, on its own

motion, institutes a review of the

Decision within that time.

Dated at Rockville, Maryland, this 19th day

of September 1997.

For The Nuclear Regulatory Commission.

Samuel J. Collins,

Director, Office of Nuclear Reactor

Regulation.

BILLING CODE 7690–01–P
50640 Federal Register / Vol. 62, No. 187 / Friday, September 26, 1997 / Notices
Federal Register / Vol. 62, No. 187 / Friday, September 26, 1997 / Notices 50641
50642 Federal Register / Vol. 62, No. 187 / Friday, September 26, 1997 / Notices

[FR Doc. 97–25632 Filed 9–25–97; 8:45 am]

BILLING CODE 7690–01–C