ML16341F375
| ML16341F375 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon  |
| Issue date: | 10/13/1989 |
| From: | Rood H Office of Nuclear Reactor Regulation |
| To: | Shiffer J PACIFIC GAS & ELECTRIC CO. |
| Shared Package | |
| ML16341F376 | List: |
| References | |
| TAC-55305, TAC-68049, NUDOCS 8910260084 | |
| Download: ML16341F375 (14) | |
Text
October 13, 1989 Docket Nos. 50-275 and 50-323 Mr. J.
D. Shiffer, Vice President Nuclear Power Generati on c/o Nuclear Power Generation, Licensing Pacific Gas and Electric Company 77 Beale Street, Room 1451 San Francisco, Califor nia 94106
Dear Mr. Shiffer:
DISTRIBUTION 0
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NRC 5 LPDRs GBagchi MVirgilio NChokshi JLee RRothman BGrimes LReiter EJordan ACRS (10)
OGC (for information only)
PDV Plant File
SUBJECT:
TRANSMITTAL OF DOCUMENTS AND REQUEST FOR ADDITIONAL INFORMATION RELATING TO NRC STAFF REVIEW OF DIABLO CANYON LONG TERM SEISMIC PROGRAM (LTSP)
(TAC NOS.
55305 AND 68049)
Enclosed are four items which relate to the NRC staff review of the Diablo Canyon Seismic Reevaluation Program.
The enclosed material is as follows:
1.
NRC Staff Questions About LTSP Seismic Source Characterization 2.
Letter report on the 8-10 August 1989 meeting on Seismic Source Characterization of the Diablo Canyon Long Term Seismic Program, 21 September
- 1989, by Keiiti Aki, Department of Geological
- Sciences, University of Southern California, Los Angeles, CA.
3.
Letter report on the August 8-10 meeting on Seismic Source Characterization, 25 September
- 1989, by Robert D. Brown, U.S.
Geological Survey, Menlo Park, California.
4.
Letter report on the August 8-10, 1989 NRC/PGImE Meeting on Seismic Source Characterization, September 19, 1989, by David B. Slemmons, University of Nevada-Reno,
- Reno, Nevada.
In order to maintain our review schedule, we request that you provide the additional information identified in Enclosure 1 by November 30, 1989. If you have any questions regarding this request, please contact me.
Sincerely, ori ginal si gned by Harry Rood, Senior Project Manager Project Directorate V
Division of Reactor Projects - III, IV, V and Special Projects Office of Nuclear Reactor Regulation DRSP/PD5 HRood 10/g /89
,D5 h on 1 /0/89 OFFICIAL RECORD COPY
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Docket Nos. 50-275 and 50-323 UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 13 October 1989 Mr. J.
D. Shiffer, Vice President Nuclear Power Generation c/o Nuclear Power Generation, Licensing Pacific Gas and Electric Company 77 Beale Street, Room 1451 San Franci sco, Ca lif ornia 94106
Dear Mr. Shiffer:
SUBJECT:
TRANSMITTAL OF DOCUMENTS AND REQUEST FOR ADDITIONAL INFORMATION RELATING TO NRC STAFF REVIEW OF DIABLO CANYON LONG TERM SEISMIC PROGRAM (LTSP)
(TAC NOS.
55305 AND 68049)
Enclosed are four items which relate to the NRC staff review of the Diablo Canyon Seismic Reevaluation Program.
The enclosed material is as follows:
1.
NRC Staff Questions About LTSP Seismic Source Characterization 2.
Letter report on the 8-10 August 1989 meeting on Seismic Source Characterization of the Diablo Canyon Long Term Seismic
- Program, 21 September
- 1989, by Keiiti Aki, Department of Geological
- Sciences, University of Southern California, Los Angeles, CA.
3.
Letter report on the August 8-10 meeting on Seismic Source Characterization, 25 September
- 1989, by Robert D. Brown, U.S.
Geological Survey, Menlo Park, California.
4.
Letter report on the August 8-10, 1989 NRC/PGRE Meeting on Seismic Source Characterization, September 19, 1989, by David B. Slemmons, University of Nevada-Reno,
- Reno, Nevada.
In order to maintain our review schedule, we request that you provide the additional information identified in Enclosure 1 by November 30, 1989.
If you have any questions regarding this request, please contact me.
Sincerely,
Enclosures:
as stated cc w/encl:
See next page Harry Roo
, Senior Project Manager Project Directorate V
Division of Reactor Projects - III, IV, V and Special Projects Office of Nuclear Reactor Regulation
Mr. J.
D. Shiffer Paci fi c Gas and E 1ectri c Company Diablo Canyon CC:
Richard F. Locke, Esq.
Pacific Gas 5 Electric Company Post Office Box 7442 San Francisco, California 94120 Ms. Sandra A. Silver 660 Granite Creek Road Santa Cruz, California 95065-Mr. Peter H. Kaufman Deputy Attorney General State of California 110 West A Street, Suite 700 San Diego, California 92101 Managing Editor The Count Tele ram Tribune 1
2 o nson venue P. 0.
Box 112 San Luis Obispo, California 93406 Ms. Nancy Culver 192 Luneta Street San Luis Obispo, California 93401 Regional Administrator, Region Y
U.S. Nuclear Regulatory Commi ss ion 1450 Maria Lane, Suite 210 Walnut Creek, California 94596 Mr. John Hickman Senior Health Physicist Environmental Radioactive Mgmt. Unit Environmental Management Branch State Department of Health Services 714 P Street, Room 616 Sacramento, California 95814
, NRC Resident Inspector Diablo Canyon Nuclear Power Plant c/o U.S. Nuclear Regulatory Commission P. 0.
Box 369 Avila Beach, California 93424 Bruce Norton, Esq.
c/o Richard F..Locke, Esq.
Pacific Gas and Electric Company Post Office Box 7442 San Francisco, California 94120 Dr. R. B. Ferguson Sierra Club - Santa Lucia Chapter Rocky Canyon Star Route Creston, California 93432 Chairman San Luis Obispo County Board of Supervisors Room 270 County Government Center San Luis Obispo, California 93408 Michael M. Strumwasser, Esq.
Special Assistant Attorney General State of California Department of Justice 3580 Wilshire Boulevard, Room 800 Los Angeles, California 90010
Mr. J.
D. Shiffer Pacific Gas and Electric Company Diablo Canyon Long Term Seismic Program CC:
Dr. Keiiti Aki Department of Geological Sciences University Park University of Southern California Los Angeles, California 90089-0741 Dr. Ralph J. Archuleta Department of Geological Sciences University of California Santa Barbara Santa Barbara, California 93106 Dr. Steven M. Day Department of Geological Science San Diego State University San Diego, California 92182 Dr. George Gazetas Dept. of Civil Engineering 212 Ketter Hall SUNY-Buffalo Buffalo, New York 14260 Dr. Robert D. Brown, Jr.
U.S. Geological Survey Mail Stop 9??
345 Middlefield Road.
Menlo Park, California 94025 Dr. David B. Slemmons Center for Neotectonic Studies MacKay School of Mines University of Nevada-Reno
- Reno, Nevada 89557-0047 Dr. Robert Fitzpatrick Building 130 Brookhaven National Laboratory
Box 808 Livermore, California 94550 Dr. Anestis S. Veletsos 5211 Paisley Avenue
- Houston, Texas 77096 Dr.
Ken Campbell U.S.'eological Survey P.O.
Box 25046, Mail Stop 966 Denver Federal Center
- Denver, Colorado 80225 Dr. C. J. Costantino Building 129 Brookhaven National Laboratory
- Upton, New York 11973 Dr.
M. K. Ravindra E(E 3150 Bristol Street, Suite 350 Costa Mesa, California 92626 Dr. Michael Bohn Sandia Lab. - Organization 6412 Post Office Box 5800 Albuquerque, New Mexico 87185 Dr. J.
Johnson EgE 595 Market Street - 18th Floor San Francisco, California 94105
ENCLOSURE 1
NRC Staff guestions About Diablo Canyon LTSP Seismic Source Characterization 1.
Provide additiona1 support for the choice of logic tree parameters and weights used in the seismic source characterization
- analyses, including a description of the solicitation process of the PG&E panel from which the weighting of the various source characteristics were derived and applied in the program.
2.
The sense of slip PGSE derives for the Hosgri fault is based on evidence of strike-slip observed on the San Simeon fault 50 kilometers north of the Diablo Canyon site.
Geologic and geophysical data along the Hosgri fault appear to offer more direct evidence of a thrust or reverse component of slip.
This evidence includes:
a.
A thick upper Pliocene and quaternary marine section west of the fault that is juxtaposed against a basement
- surface, or a thin cover of upper quaternary sediment on basement, east of the fault.
b.
Angular unconformities (top Miocene and mid-Pliocene) that are deformed as they approach the fault from the west; southwest dips on the top-Niocene unconformity range up to 40 degrees, those on the mid-Pliocene unconformity up to 20 degrees.
These relations indicate that the fault has had a vertical component of slip during the Pliocene and probably well into the quaternary.
c ~
The wedging-out against the western face of the Hosgri (or over its blind western branches) of unconformity-bound packets of Pliocene and younger strata.
The wedging, together with the deformation described
- above, indicates a growth fault that has been active since early Pliocene time.
Moreover, it demonstrates that the time values assigned to the two unconformities may become unreliable near the fault and in the block to the northeast of it; in these regions each unconformity represents a much greater depositional, or time, gap.than it does to the west, in the offshore Santa Haria basin.
d.
A warped and faulted present-day sea floor and a similarly deformed late Wisconsinan (18Ka) surface follow the same trend, and indicate the same sense of vertical slip, as that defined by the late Pliocene and quaternary structures along the Hosgri.
e.
The broad Hosgri fault zone now separates a subsiding depositional basin on the southwest from a stable or rising wave-cut platform on the northeast; the present boundary and stratigraphic relations across the fault closely mimic those that prevailed during the earlier history of the Hosgri.
In light of these factors justify the interpretation of the Hosgri fault as being predominantly strike-slip in character.
ENCLOSURE 1 (continued)
NRC Staff guestions About Diablo Canyon LTSP Seismic Source Characterization 3.
Provide a detailed discussion of how and why the average displacement estimated for the San Simeon fault was applied to the Hosgri fault as a
maximum displacement.
4.
The characterization of the Hosgri fault a's a predominantly strike-slip fault has been questioned because of the presence of low dip angle reverse faults in the zone.
It has been suggested that other faults which are known to be strike-slip may have low dip angle reverse or thrust faults associated with them in a manner similar to that seen along the Hosgri.
If there is geophysical evidence for such a situation provide it.
The San Gregorio fault in the vicinity of Nonterey Bay has been mentioned as a possible candidate.
5.
Faults of the southwest boundary zone of the San Luis-Pismo block are the closest faults to the Diablo Canyon site, particularly the San Luis Bay and Olson faults.
The most recent analyses of these faults should be submitted.
PGRE models the southwest border of the San Luis-Pismo block as a diffuse zone of faulting and considers the small faults expressed at the surface as individual seismic sources.
Address the possibility that the entire southwest border zone may be integrated at seismogenic depth and may have the potential for a larger earthquake than the individual faults.
What effect would this have?
6.
PGSE has interpreted the Los Osos fault on the. northeast side of the San Luis-Pismo block; and the Olson, San Luis Bay, and Wi'Imar Avenue faults on its southwest side as near-vertical, block-boundary faults along which the block has been uplifted.
Is this model consistent with the geologic information listed below'lease explain PGSE's inter pretation.
a.
Surface geologic data from the Los Osos and San Luis Bay faults, which document low or moderate dips inward, toward the synclinal axis.
b.
Subsurface geologic data from the Honolulu-Tidewater drill hole, which show multiple repetition of Tertiary strata in the lower part of the hole, down to the total depth of about 11,000 feet; dips in the repeated section are low to moderate in sharp contrast to the steeper dips at the surface and'n the upper part of the hole.
c.
Surface geologic map relations which require post-Pismo compression, folding and reverse or thrust faulting.
ENCLOSURE 2
DEPARTMENT OF GEOLOGICALSCIENCES TELEPHONY.: (213) 743-2717 21 September 1989 i-(- e:-i/-'.
Xgr
't Dr. Jean Savy MS L-196 LLNL P.O. Box 808 Livermore, CA 94550
Dear Jean:
This is my belated report on the 8-10 August 1989 meeting on Seismic Source Characterization of the Diablo Canyon Long Term Seismic Program.
With regard to the characterization ofevents on the Hosgri fault, I confirmed my impression described in my last letter (15 June 1989) reporting on the Geology/Seismology/Geophysics/Tectonics meeting. My assessment of the Hosgri fault is the following. It is not a San Andreas fault, and willnever generate fault slip of 6 to 10 meters.
On the other hand, itwillprobably generate a greater earthquake than the Newport-Inglewood fault which slipped by about 30 cm during the 1933 Long Beach earthquake, because the PG and E estimated a single-event slip of 1 to 2 meters for the nearby San Simeon fault. Itis very reasonable, therefore, to compare the Hosgri fault with the San Jacinto fault which is intermediate in seismic source character between the San Andreas and the Newport-Inglewood fault as done by Kevin Coppersmith.
I was concerned, however, about the evaluation of seismic hazard for the Los Osos, San Luis Bay and Olson fault. I was most concerned about the fact that there have been absolutely no discussion of these nearby thrust faults in the Ground Motion meetings ofLTSP. I understand that the reason is because their contribution to the final "hazard curve" is lower than that of the Hosgri fault due to lower rates oftheir recurrences.
- But, the comparison in the final hazard curve depends on the level of ground motion due to events expected on these faults. In view of the uncertainty in the characterization ofthese nearby thrust faults, I felt that more careful studies on the ground motion expected from these faults are necessaiy.
Perhaps, numerical simulations ofthrust fault models with validation against the abundantly observed ground motion during the Whittier Narrows earthquake of 1987 would be useful for this purpose. I hope that we shall have some discussion on this issue. during the next Ground Motion meeting scheduled on 25-26 October 1989.
Finally, I was very much interested in the "discrete discriminant analysis" of segmentation data presented by PG and E as a new approach toward more objective characterization of seismic source.
Sincerely yours, I
I,'>>
KeiitiAki UNIVERSITYOF SOUTHERN CALIFORNIA,UNIVERSITYPARK, LOS ANGELES, CALIFORNIA 90089-0740