ML20148B774

Forwards Request for Addl Info Re Geological & Seismological Aspects

ML20148B774
Person / Time
Site:	Skagit
Issue date:	01/08/1980
From:	Stolz J Office of Nuclear Reactor Regulation
To:	Mecca J PUGET SOUND POWER & LIGHT CO.
Shared Package
ML20148B779	List: ML20148B774
References
B00108, B108, NUDOCS 8001230285
Download: ML20148B774 (7)

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o, UNITED STATES

[g.,}., *'j NUCLEAR REGULATORY COMMISSION WASHINGTON. D. C. 20555 t

JAN 81%0 Docket Nos. 50-522 and 50-523 Mr. J. E. Mecca, Manager Nuclear Licensing and Safety Puget Sound Power & Light Ccmpany Puget Power Building Bellevue, Washington 98009

SUBJECT:

SKAGIT NUCLEAR POWER PROJECT, UNITS l'& 2 The enclosed joint NRC-USGS requests for additional information have been developed in response to new inforntion provided to the NRC on October 10, 1979 by the U. 5. Geological Survey regarding geological and seismological aspects of the northern Puget Sound area.

Please advise us as to when you feel you may be able to respond to the enclosed requests.

Also enclosed is a copy of Robert E. Jackson's letter to James F. Devine, dated January 4,1980, for your information. This letter requests a clari-fication of the overall intent of the USGS questions and also solicits the USGS views on the likelihood of accomplishing a number of geological investi-gations.

We have requested a January 22, 1980 response to this letter.

Sincerely,

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[Jo F. Stolz, Chief Li t Water Reactors ranch No. I pisionofProjectManagement

Enclosures:

As stated cc:

See next page i

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Mr. J. E. Mecca JAN 8 1980 cc:

V. B. Deale, Esq., Chairman Thomas F. Carr, Lsq.

Atomic Safety & Licensing Board Assistant Attorney General U. S. Nuclear Regulatory Commission Temple of Justice Washington, D. C.

20555 Olympia, Washington 98504 Dr. Frank F. Hooper, Mecter Mr. F. Theodore Thomsen Atomic Safety & Licensig Board Perkins, Coie, Stone, School of Natural Resources Olsen & Williams University of Michigan 1900 Washington Building Ann Arbor, Michigan 48109 Seattle, Washington 98101 Mr. Gustave A. Linenberger, Merber l.

Mr. Robert Lowenstein Atomic Safety & Licensing Board Lowenstein, Newman, Reis U. S. Nuclear Regulatory Commission

& Axelrad Washington, D. C.

20555 Suite 1214 1025 Connecticut Avenue, N. W.

Washington, D.C.

20036 Roger M. Leed, Esq.

Law Offices L..

1411 4th Avenue Seattle, Washington 98101 Mr. Lloyd X. Marbet c/o Forelaws on Board 19142 South Bakers Ferry Road Boring, Oregon 97009 Mr. Nicholas D. Lewis, Chairman Energy Facility Site Evaluation Council 820 East 5th Avenue

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Olympia, Washington 98504 b-

?N' Honorable Richard Sandvik

$lR Department of Justice l?. ).

T 500 Pacific Building 520 Southwest Yamhill

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Portland, Oregon 97204 4., ' 8 e

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I REQUESTS FOR ADDITIONAL INFORMATION PUGET SOUND POWER AND LIGHT COMPANY SKAGIT NUCLEAR POWER PROJECT, DOCKET NOS. STN Sh i +

Questions:

1 1.

In view of the recent acknowledgement by consultants to the applican nat (323.86) the contact between the Chuckanut Formation and the Shuksan !!etamrplics is a high-angle fault where it crosses Loretta Creek (conference in Bethesda, Maryland, October 26, 1979) and of increased concern regarding the likelihood of high-angle faults elsewhere in the site region, the applicant should investigate in detail the possibility that all or some of the movement evidenced by shearing at and near the Chuckanut-Shuksan contact in drill holes and trenches northeast of the proposed Cate pry I structures was produced by a fairly high-angle fault that is younger than the principal folding of the Chuckanut Formation and is not fund:montally related to the basal contact of that formation.

Such a f; ult might form the contact of the Chuckanut only locally and at shallow depth and be entirely within the older rocks elsewhere.

In planning an investigation that will establish or preclude such an interpretation of shearing along and' near the Chuckanut contact at the plant site, the applicant might consider, but not limit its thinking to, the folicwing studics:

a.

Determination, northeast of the proposed Category I structures, of the precisc location and dip of the Chuckanut-Shuksan contact and any faulting in its vicinity, from the surface to an appropriate depth.

b.

Excavation, for inspection and mapping, of an exposure of the contact and the bedrock on both sides that is of such size and character that the absence or presence of faulting can be incontrovertibly demonstrated.

c.

t'uch' mere detailed investigation and mapping of the geology in the vicinity of the Chuckanut-Shuksan contact, in the northwestern part of the site area and between the site area and the Semish River.

2.

'The applicant (RGI, Appendix H, sheet 1) maps an almost-continuous strip of glacial deposits along the south edge of the Skagit River valley, from (323.87) several miles west of Gilligan Creek eastward across Gilligan, Day, and Loretta Creeks to Cumberland Creek.

In view of the recognition of fculting in lower Loretta Creek valley by Uhetten and others (1979) and, later, by the applicant, and of concern regarding high-angle faulting east of Gilligan Creek and possibly elsewhere in the region, the applicant's discussion of possible deformation of Quaternary deposits, in response to NRC Request 323.84 is inadequate. There is no analysis of terrace surfaces on the glacial and younger deposits along the south side of the Skagit River valley, and no map differentiation of the glacial deposits nor of the lateral extent of the units described within the glacial deposits (RGI, p. 3.2-5).

Finally, there is no discussion of the structural control that features of these types may provide by their distributions and elevations. The applicant should correct these deficiencies, and, similarly, it should consider and, if desirabls, carry out further Quaternary studies on the north side of the Skagit River valley.

The applicant should substantiate, if possible, its 1

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interpretation of the Quaternary deposits around the mouth of Gilligan I

Creek as being older than Fraser Glaciation and its suggestion that a till deposit there may be of Salmon Springs age.

3.

In view of recent recognition of the existence of additional marine (323.88) seismic profiles within and north of the San Juan Islands (the 1971 lines of Western Geophysical Corp.) and the need for integrating interpretations of the various sets of marine profiles, the applicant should provide (1) a map showing all seismic profiles in the southern Strait of Georgia-San Juan Islands-northern Puget Sound region and all tectonic structures that are or might reasonably be inferred from study of the profiles and (2) the approximate " shot-point" locations of the intercepts of the structures with the profiles.

4.

The applicant should clarify the following discrepancies in Appendix A of (323.89) the RGI:

Regarding figure 5 (also referred to as " Area B" and " Sheet 2A"):

It -

a.

is indicated in this figure that the flight lines were north-south, while Appendix 3 indicates that they were east-west.

b.

Regarding figure 6 (also referred to as " Area E" and " Sheet 5"):

It is indicated in this figure, in figure 1, and in the text that the lines were flcun at a,500 ft, barometric, while Appendix 3 states that they wara flown at 2,500 ft, barometric.

c.

Sgardingfigure7(alsoreferredtoas"AreaF"and" Sheet 6"):

It is indicated in this figure, in figure 1, and in the text that the lines were flcun at 2,500 ft, barometric, while Appendix 3 states that they were flcun at 4,500 ft, barometric, d.

In the report by M. E. Beck, Jr., that is included in Appendix A of the RGI, what are the meanings of declinations greater than 360 dagrees?

5.

Because present data are inadequate in helping to define the attitude of (323.90) the centroversici Haystack-Shuksan thrust fault, the applicant should consider providing other geophysical data to resolve the question.

6.

Concern regarding the extent and location of the "Loveseth fault" (323.91) northwest of section 3, T. 33 N., R. 5 E. (approximately located but interpreted as normal contact in RGI, Appendix H, sheet 1) and of the

" Table Mountain fault" northwest of the Table Mountain vicinity (Whetten, Dethier, and Carroll,1979, near southwest corner of maps) and ongoing mapping by USGS geologists in the region prcmpt the following requests for more information regarding the Walker Valley-Clear Lake vicinity:

a.

Explain basis for moving the Chuckanut exposure shown in center of section 33. T. 34 N., R. 5 E. in 1978 version of regional geologic map (Exhibit 132; 1:62,500 scale) to a position farther scuthwest in the same section (RGI, Appendix H, sheet 1) and evaluate nore fully the mapping of a faulted Chuckanut contact, at or near the earlier map location, by Jenkins (1924), Loveseth (1975), Stoler (1977), and Whetten, Cethier, and Carroll (in press).

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b.

h ovide the basis for mapping (RGI, Appendix H, sheet 1) the entire exposure of rock along the boundary between sections 29 and 30, T. 34 I

N., R. 5 E., as Chucknut and the exposures in the northeast 1/4 of scetion 32 as " Church Mountain Plate"; and evaluate, in more detail, the possibility of a northwest-bearing fault contact in this vicinity, press) posed by Jenkins (1924) and Whetten, Dethier, and Carroll (in as pro Describe and explain the relationship of th'e Chuckanut formation to c.

the " Church Mountain Plate" at Big Rock (Soc. 23, T34N, R4E) and evaluate the statement by Stoker (1979) that there are deformed lake sediments in that vicinity.

d.

Explain more adequately why the contact of the Shuksan metamorphic rocks betwean the Table Mountain vicinity and Mundt Creek, to the northwest, should not be considered to be a high-angle fault zone.

e.

Describe all bedrock exposed in the hill icmediately west of Clear Lake and the hill immediately southw'est of Beaver Lake, T. 34 N.,

R. 4-5 E., and explain why these hills are assigned to the "Shuksan j

Thrust Plate".

f.

Provide the basis for mapping (RGI, Append. H, sheet 1) the exposure of rock near the center of Section 3, T33N, R5E as part of the " Church Mt. Plate".

7.

The applicant shculd explain more fully the Sackung-like features on Cole (323.92)

" untain near the Loretta Creek " fault" which were interpreted as caused solely by " gravitational forces" when similar features elsewhere are interpreted to indicate recent movement on faults near to the features.

S.

Please provide.a discussion as to the reasons why older nonglacial (323.93) deposits appear to occur only west uf the veuth of Gilligan Creek.

9.

Please riiscuss the impact of the Loretta Creek fault, now recognized by (323.94) the applicant to exist, on the interpretation of the regional tectonics since such a fault does not appear to be part of the thrust plate as is the applicant's interpretation of the southern portion of the Gilligan fault.

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323.95 Provide appropriate discussion of all the reasonably inferred tectonic structures identified in response to question 323.88. Your response should include but is not limited to (1) the probable age (s) of the tectonic structures and (2) now these structures fit into the framework of regional tectonics.

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References cited 1Jenkins, O. P.,1924, Geological investigation of the coal fields of Shagit County, Washington:

Washington State Division of Geology Bulleti.1 29.

Loveseth,T.P.,1975,TheDevilsMountainkaultZone, northwestern Washington:

University of Washington Masters thesis.

Stoker, B. A., 1977, Assessment of need for geologic mapping in the Clear Lake quadrangle, Washington:

Unpublished report rcccived from Roger Leod, August 8, 1977.

Stoker, B. A.,1979, Profiled testirc.ony before the ASI.B dated October 18, 1979, page 8.

Whetten, J. T., Dethier, 'D. P., and Carroll, P. R.,1979, Preliminary geologic map of the Clear Lake NE Quadrdangle, Skagit County, Washington:

U.S.

Geological Survey Open-File Report 79-1468.

1:hotten, J. T., Dethier, D. P., and Carroll, P. R., Preliminary Geologic map of the Clear Lake NW Quadrangle, Skagit County, Washington, in press.

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'r. J.:es F. Covine Presty for Engineering Office of Earthquake. Studies H. S. C;alcgical Su.ecy

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On about Septecher 17, 1979, we received a supplement to the U. S.

raclogical Survey;revicw (February 23, 19/8) of the geologic and scis-l nologic data relevant to the Skagit i:nclear Power Project, Units 1 and 2

(!!RC Docket !!os. 50-522 and 50-523) (letter, H. William Iicnard, USGS I

to Harold Denton, USNRC, September 17, 1979).- The conclusion of that 1

review indicates that, "The USGS reactor site review team agrees with i

the applicant's proposed use of a hea uck accelerut. ion value of 0.359

s the Safe Shutdoien Earthiiuake for use with tha %ful.y cuido 1.60 i

J.: sign spectruta for nuclear pc..nr pltat d.n!.a," The tran.aittal letter n

ice this r.ni'.w noted, :,o.;eur, l' hat t he i,ccact of the envicw of certain proprietary sois<nic profiles 1.hiih hcui not yet Scen received by USGS inuld ba transullted.d. a later date. On Ociober 2, 1979, the Coosciences nranch staff '.ranst11tted its Safuty tvaluation Report noting as an open itc.n the ca.uoletion of raview of those profiles.

In ucetings with the staff on October la,19/9, and with the staff and the

.toplicant on Octotor 26, 19/9, the i:SGS indicated that the continuing review of the tai :ic curicci.!in profilo<, additional field aapping, and further r:

palic int. r;)rai al.lon had led to serinus concerns relating to the c r Aility of a T.iily af northwat tecr. ding high. angle faults in the site acca.

!a :he 3.coeious L.pt.. Lee 11,.1979 ccview it.uas nuled that iho ago of high tngla fauli.s in the sita vicinity arc, "very probably,

'ut unccclainly, inc ;)..* ale."

On D2cechar 10, 1979, ycu forwarded questions and requests for additional I!SGS to R. E..hkson, USNRC) git :aclear Power Project (letter, J. F. Devine, infoimatico regarding the Ska At the prescat t.ime, we are preparing to forward those questions to the applicant. Our interpretation of the i

quesi. ions indic.itos to us that thero has.tcon a significant change in the Ib.rS rusicu cogarding the age oft last movaaent of high angle faults and

.ia ocu larecive that you advice is I.hnt such fe.ults in the site v.icinity should

' a unsidcred capable until cach bne is proved to be not capabic.

The dc.enstration j

of mch non-capability uill i... pose a significant ncw burden of proof on both 90028026 s 0012 30 2 M

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e$ic.c.cs.

It is i:.portant, thcrofore, that

.a..... s t a cl..rificatian vf !!ic..s. i lli ini a.it of Iho ;1estions previ.!.91 In dlition, ue also solicit li.c IMS vicus un Uic likelifmod of:

1) locating and identifying all such faults in the complex geologic terrain in the site vicinity;

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he in..scnce of str t.*3r..phic horizcns of sufficiust age to dcmastrale

.r a c..,.c.'; i 1 i Ly; 3) foi U.cc questicas relating to sito safety as a result of continued field.: ;.gir.g and interpretations; and,

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4) finding that the proposed scissa-ic design i.ialue of 0.359 is inadcquato.

We would appreciate your early response to th.is letter in order that we t.:ay use the information provided to aid us in preparation for a requested pii. hearing conference with the.itenic Safety and Licensing Board on Lauary 22, 1930.

Siricercly yours,

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. Robert E. Jackson, Chief Geosciences Branch Division of Systems Safety i

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