ML13302A850
| ML13302A850 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 10/16/1980 |
| From: | Rood H Office of Nuclear Reactor Regulation |
| To: | Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8010300151 | |
| Download: ML13302A850 (11) | |
Text
ik f!UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, 0. C. 20555 OCT 1 6 1980 Docket Nos. 50-361/362 APPLICANTS: SOUTHERN CALIFORNIA EDISON COMPANY (SCE)
SAN DIEGO GAS AND ELECTRIC COMPANY (SDG&E)
FACILITY:
SAN ONOFRE NUCLEAR GENERATING STATION, UNITS 2 AND 3
SUBJECT:
SUMMARY
OF MEETING ON SAN ONOFRE SEISMOLOGY AND GEOLOGY On September 23, 1980, members of the NRC staff and their consultants, the U.S. Geological Survey (USGS), the California Division of Mines and Geology (CDMG), and the applicants met in Menlo Park, California, to discuss the above subject. Attendees at the meeting are given in Enclosure 1. The meeting agenda is given in Enclosure 2. A summary of the technical presentations and discussions at the meeting is given below.
P. Ehlig (consultant to SCE) discussed the geologic and tectonic development of the southern California coastal area since about 15 million years before the present (MYBP). Specifically, he discussed the tectonic development of the Capistrano Embayment and the origin and history of movement of the Cristianitos fault. His general conclusion was that the Cristianitos is a listric fault (i.e., a fault that bends at depth) and was most likely developed due to gravity sliding with associated buckling. He concluded that the tectonic development of the Cristianitos fault began approximately 10 to 15 MYBP and ended in the Pliocene (approximately 4 MYBP).
R. Schlemon (consultant to SCE) reviewed wave-cut bench formation and the subsequent terrace deposits, including an evaluation of the age dates of high stands of sea level during the past 780,000 years. In addition, he reviewed the uplift rates of the terrace deposits along the southern California coast.
He concluded that there has been no differential uplift across the onshore trace of the Cristianitos fault during the last 125,000 years, and, most likely, for a much longer period of time.
D. Moore (consultant to SCE) presented a comprehensive interpretation of all the available offshore seismic reflection data. He stated that most of the faulting along the offshore projection of the Cristianitos fault are contained within the Miocene (11 to 25 MYBP) Monterey formation. He also noted that a major syncline flanks the Offshore Zone of Deformation (OZD), to the east, for several miles in the vicinity of San Onofre.
G. Greene of the USGS (advisors to the NRC staff) also reviewed the offshore data and presented arguments for a Cristianitos "Zone of Deformation" offshore. His presentation included his recent review of the Nekton data (which had not been included in his report transmitted by cover letter dated August 13, 1980,
-2 Robert H. Morris to Robert Jackson). His conclusions generally supported the conclusions of Moore regarding the origin and age of the faults and folds between the shoreline and the OZD in the vicinity of San Onofre. He also noted the continuous syncline which is immediately inshore of and parallel to the OZD. He concluded that the new data (Nekton) is of excellent quality and provides.a good confirmation of the previous work in the adjacent area (Woodward-Clyde profiles obtained in 1978).
He further concluded that the nature of the possible intersection of the CZD and the OZD is not known.
J. Andrews of the USGS (advisors to the NRC staff) commented on the applicant's proposed slip-rate versus magnitude relationship, indicating several possible difficulties associated with the data set used. These included exclusion of data from Japanese strike-slip faults and from other, non-strike-slip faults.
He also discussed an hypothesis for a model study comparing the San Onofre 2 and 3 SSE with the October 15, 1979 Imperial Valley earthquake, including elements such as amplification, attenuation, stress drop, and stress-drop scaling. This point was responded to, later during the discussion period, by the applicant's consultant, G. Frazier. He indicated that these elements had been considered in the development of the model used to analyze San Onofre Unit 1. B. Slemmons (NRC staff consultant) also discussed the validity of not including Japanese and other data in a slip-rate versus magnitude relationship, and concluded that the applicant's treatment was reasonable.
E. Heath and W. Savage (consultants to SCE) discussed faulting and seismicity in Baja California. They concluded that there is no compelling evidence for a connection between the Baja faults (the San Miguel, Vallecitos, Calabasas, Tres Hermanos, and Agua Blanca faults) and the OZO or its southerly extension, the Rose Canyon fault. M. Kennedy of CDMG noted that the scarcity of fault data immediately to the south of San Diego Bay may be due to concealment by younger strata.
The applicant's studies were summarized by J. Smith.
His conclusions are given in Enclosure 3.
After the above presentations were made, a discussion period followed, during which the following issues were discussed:
- 1. Magnitude saturation, i.e., the saturation of peak acceleration as a function of earthquake magnitude and the distance from the fault rupture.
- 2. Vertical.acceleration.components of the 1979 Imperial Valley earthquake.
- 3. The appropriateness of the distance range of the records used by the applicants to compare the Imperial Valley earthquake to the San Onofre 2 and 3 SSE.
-3
- 4. The effect of differences in site conditions on the comparison of the Imperial Valley earthquake and the San Onofre 2 and 3 SSE.
- 5. The various methods of estimating the magnitude of the San Onofre 2 and 3 SSE.
- 6. Focusing effects of the SSE, specifically, whether the specific orientation of the OZD south of San Onofre would focus energy towards the plant in the event of a fault rupture beginning to the south of the plant and propagating northward.
- 7. The relationship of the A, B, C, D features (found during plant excavation) to the tectonic framework of the Capistrano Embayment.
At the end of the meeting, the NRC staff requested that the applicants provide the following information on the San Onofre 2 and 3 docket:
- 1. An earthquake spectra based on a magnitude 7.5 event occurring on the OZD, as previously requested in Q361.54.
- 2. The material presented at the September 23, 1980 meeting by P. Ehlig.
- 3. The material presented at the September 23, 1980 meeting by 0. Moore.
- 4. A discussion of the relationship of the A, B, C, D features.to the tectonic framework of the Capistrano Embayment.
Harry Rood Licensing Branch #3 Division of Licensing
cc:
Charles R. Kocher,.Esq.
Jaimes A. Beoletto, Esq.
Scuthern California Ediscn Company 2244 WaInut Grove Avenue P. 0. Box 800 Rcsemead, California 9177C ChicKering & Grerory
'TN:
David R. Pigott, Esq.
Counsel for San Diesc Gas & Electric Company Southern California Edison Company 3 Embarcadero Carer -
23rd Floor San Francisco, California 94112 Mr. Georce Caravaiho City Manager C
of San CIemente 100 Avenico Presidio San Clemente, California 92672 Alan R. Watts, Esq.
Rourke & Woodruff Suite 1020 105 North Main Street Santa Ana, California.92701 Lawrence Q. Garcia, Esq.
California Public Utilities Commissicn 5066 State Buildinc San Francisco, California 94102 Mr. V. C. Hall Combustion Engineering, Incorporated 1000 Prospect -ill Road Windsor, Connecticut 06095
Mr. Robert Dietch 2
Mr. B. W. Gilman cc:
Mr. P. Dragolovich Bechtel Power Corporation P. 0. Box 60860, Terminal Annex Los Angeles, California 90060 Mr. Mark Medfcrd Southern California ECison Company 2244 Walnut Grove Avenue P. 0. Box 800 Rosemead, California 91770 Henry Peters San Diego Gas & Electric Company P. 0. Box 1831 San Diego, California 92112 Ms. Lyn Harris Hicks Advocate for GUARD 3908 Calle Ariana San Clemente, California 92672 Richard J. Wharton, Esq.
Wharton & Pcgalies Suite 106 2667 Camino Del Rio South San Diego, California 92108 Phyllis M. Gallagher, Esq.
Suite 222 1695 West Crescent Avenue Anaheim, California 92701 Mr. A. S. Carstens 2071 Caminito Circulo Norte Mt. La Jolla, California 92037 Resident inspector, San Onofre/NPS c/o U. S. Nuclear Regulatory Commission P. 0. Box AA Oceanside. California 92054
Mr. Robert Dietch
- 3 Mr. B. W. Gilman cc: California Department of Health ATTN: Chief, Environmental Radiation Control Unit Radiological Health Section 714 P Street, Room 498 Sacramento, California 95814 Director Energy Facilities Siting Division Energy Resources Conservation &
Development Commission 1111 Howe Avenue Sacramento, California 95825
- Chairman, Board of Supervisors San Diego County San Diego, California 92412 Mayor, City of San Clemente San Clemente, California 92672 U. S. Environmental Protection Agency ATTN:
EIS Coordinator Region IX Office 215 Freemont Street San Francisco, California 94111 Energy Resources Conservation &.
Development Commission ATTN:
Librarian 111 Howe Avenue Sacramento, California 95825
ENCLOSURE 1 ATTENDEES SEPTEMBER 23, 1980 MEETING SAN ONOFRE SEISMOLOGY/GEOLOGY NAME ORGANIZATION H. Rood NRC-LB3 L. Reiter NRC-GSB R. L. Rothman NRC-GSB A. T. Cardone NRC-GSB L. J. Chandler NRC-OELD D. B. Slemmons NRC Consultant (Univ. Nev.)
G. Quittschreiber NRC/ACRS R. Jackson NRC-GSB C. Smith S. D. Union D. Perlman San Francisco Chronicle P. Grew Dept. Conservation, St. of Calif.
J. Davis CDMG A. Morris USGS J. Devine USGS R. Vo1lmer NRC-DE J. Knight NRC-DE P. Amimoto CDMG D. Hadley Sierra Geophysics H. Peters SDG&E R. Rouch San Diego Tribune L. Wight TERA F. Brady Pacific Gas & Elec. Co.
D. Moore SCE J. McNey SCE J. Smith SCE (consultant)
M. Balderman SCE (consultant)
R. Sholes SCE R. McNeill SCE (consultant)
R. Willingham Earth Sciences Assoc.
G. Frazier SCE (consultant)
V. Ghio Pacific Gas & Elec.
Co.
C. Roberts Orange County Register Lloyd Cluff Woodward-Clyde Consultants K. McNally Consultant to Woodward-Clyde W. Savage Woodward-Clyde Consultants R. Nason US Geological Survey I. Idriss Woodward-Clyde Consultants
- 0. Tillson Wash. Public Power Supply System G. Greene USGS M. Kennedy CDMG R. Wallace USGS D. McCollough USGS
-2 (ATTENDEES)
NAME ORGANIZATION
- 0. Hamilton ESA J. Barneich Woodward-Clyde S. Smith Consultant to SCE P. Somerville Woodward-Clyde P. Guptiel Woodward-Clyde E. Heath Woodward-Clyde
- 0. Streiff Woodward-Clyde J. Egan Woodward-Clyde R. Shlemon Consultant to SCE K. Baskin SCE D. Pigott Chickering and Gregory J. Beoletto SCE R. Sadigh Woodward-Clyde
- 0. Barron So. Calif. Edison M. Medford SCE W. Moody SCE P. West SCE G. Barlow Friends of the Earth D. Andrews USGS H. Hawkins SCE S. Biehler SCE (consultant)
ENCLOSURE 2 MEETING TO DISCUSS THE GEOLOGY AND SEISMOLOGY OF SAN ONOFRE NUCLEAR GENERATING STATION UNITS 2 AND 3 MENLO PARK, CALIFORNIA SEPTEMBER 23, 1980 I. Introduction/Meeting Objectives W. C. Moody II. Significance of Cristianitos Fault and P. Ehlig OZD to Geologic Setting of San Onofre R. Shlemon Area III.
Recent Offshore Geophysical Studies D. Moore IV. Offshore Cristianitos Fault Extension-G. Greene Interpretation of High Resolution M. Kennedy Seismic Reflection Profiles V. Degree of Fault Activity and Analysis J. Andrews of Imperial Valley Ground Motion Data VI.
Relationship Between OZD and Baja Faulting Faulting Tectonics E. Heath Seismicity, Historic Earthquakes W. Savage VII.
Summary of Geotechnical Findings J. Smith VIII.
Open Discussion All
ENCLOSURE 3 SCE CONCLUSIONS
- 1. There is no compelling geologic evidence for a connection of the San Miguel fault zone to the OZD; in fact, the preponderance of evidence is heavily against any connection.
- 2. Neither the San Miguel fault zone nor the AGUA Blanca fault zone extend east of the Sierra Juarez and thus do not connect with the transform fault system of the Gulf of California.
- 3.
The tectonic models considered for Baja and Southern California do not require connection of the OZD to faults in Baja and suggest different origins for faulting in northern Baja and in Southern California.
- 4. Historical seismicity is consistent with tectonic models considered with large earthquakes occurring on the plate boundary and other identified active faults.
- 5. The spatial patterns of seismicity do not suggest or support the existence of connected and throughgoing fault zones between the OZD, continental borderland offshore faults, and faults in Baja California.
MEETING
SUMMARY
DISTRIBUTION Docket File G. Lear V. Noonan Local POR S. Pawlicki TIC/NSIC/Tera V. Benaroya NRR Reading Z. Rosztoczy LB#1 Reading W. Haass H. Denton D. Muller E. Case R. Ballard D. Eisenhut W. Regan R. Purple D. Ross B. J. Youngblood P. Check A. Schwencer R. Satterfield F. Miraglia
- 0. Parr J. Miller F. Rosa G. Lainas W. Butler R. Vollmer W. Kreger J. P. Knight R. Houston R. Bosnak T. Murphy F. Schauer L. Rubenstein R. E. Jackson T. Speis Project Manager H. Rood W. Johnston Attorney, OELD J. Stolz M. Rushbrook S. Hanauer OIE (3)
W. Gammill ACRS (16)
R. Tedesco F. Schroeder D. Skovholt M. Ernst NRC
Participants:
R. Baer C. Berlinger H. Rood K. Kniel L. Reiter G. Knighton R. Rothman A. Thadani A. Cardone D. Tondi L. Chandler J. Krammer G. Quittschreiber 0, Vassallo R. E. Jackson P. Collins R. Vollmer
- 0. Ziemann J. Knight D
bcc:
Applicant & Service List 8 0108 OM5\\