ML16341E264
| ML16341E264 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon  |
| Issue date: | 05/29/1987 |
| From: | Crutchfield D Office of Nuclear Reactor Regulation |
| To: | Asselstine, Bernthal, Zech NRC COMMISSION (OCM) |
| References | |
| CON-#287-3660, TASK-AS, TASK-BN87-010, TASK-BN87-10 BN-87-010, BN-87-10, OLA, NUDOCS 8706090341 | |
| Download: ML16341E264 (12) | |
Text
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UNITEDSTATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 3 ~ MAY 1887 Docket Nos.
50-275 and 50-323 MEMORANDUM FOR:
FROM:
SUBJECT:
Chairman Zech Commissioner Asselstine Commissioner Bernthal Commissioner Carr Dennis H. Crutchfield, Director Division of Reactor Projects - III, IY, Y and Speical Projects BOARD NOTIFICATION REGARDING NEW GEOLOGIC INFORMATION RELATING TO DIABLO CANYON NUCLEAR POWER PLANT (BN 87-1O )
The purpose of this memorandum is to notify you of new geologic information pursuant to NRR Office Letter No. 19, Revision 3, which requires that the staff inform the Commission on all matters which may involve substantial public, press, or congressional interest.
This notification provides new information regarding the existence of capable faults and their proximity to the Diablo Canyon Nuclear Power Plant site.
As part of the seismic reevaluation program for the Diablo Canyon Nuclear Power Plant which is mandated by a condition of the Unit 1'icense, a geology-seismology-geophysics workshop was held in San Luis Obispo from Hay 5 through 8.
Pacific Gas and Electric Company (PG8E) made presentations on the progress of the program in geology and geophysics in the Diablo Canyon region.
The Hosgri Fault Zone which was the controlling geologic feature in the seismic analysis of the plant had been estimated to be 5.8 kilometers at its closest approach to the site.
During the workshop PG8E indicated that there is a previously unidentified strand of the Hosgri Fault Zone which has a surface trace about 4 kilometers from the Diablo Canyon site.
As a result of onshore geology and offshore geophysics investigations, PGEE has identified a capable fault, tentatively named the San Luis Bay Fault.
This fault has been identified by a displacement of a beach terrace on San Luis Bay about 10 kilometers from the plant site.
Other less definitive information including possible breaks in shoreline angle, topography and offshore geophysical data suggest that this fault may be extended offshore in the direction of the Hosgri Fault Zone.
Such a postulated extension could place the surface trace of the San Luis Bay Fault approximately 2 kilometers from the plant site.
Based on the relatively small amount of displacement of the beach terrace by this fault, it appears to have a low rate of activity.
PG8E has been conducting a very detailed investigation of the geology and geophysics of the region under the reevaluation program and this is the type of information which the program is expected to produce.
870609034l S70529 CONTACT:
PDR ADDCK 05000275 A II 0 C.
Tr ammel 1, NRR/P05 P
The Commissioners The NRC staff has kept in close contact with the Diablo Canyon reevaluation program through meetings, workshops, report reviews and independent studies.
Based on the conservatism of the original Hosgri fault evaluation, the observed relative lack of sensitivity of ground motion to distance within several kilo-meters of large earthquakes and the low rate of activity on the proposed San Luis Bay Fault the staff does not, at this time, consider this new information to be of safety concern.
Upon completion of the program defined by the license condition, the staff will review all relevant geological, seismological and engineering infor-mation to assure adequacy of seismic margins.
Or~1 stgnod by Dennis M. Crutchfield, Director Division of Reactor Projects - III, IV, V and Special Projects
- See previous concurrence 1
NAME : CTRAMMELL
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The Commissioners The NRC staff has kept in close contact with the Diablo Canyon reevaluation program through meetings, workshops, report reviews and independent studies.
Based on the conservatism of the original Hosgri fault evaluation, the observed relative lack of sensitivity of ground motion to distance within several kilo-meters of large earthquakes and the low rate of activity on the proposed San Luis Bay Fault the staff does not, at this time, consider this new information to be of safety concern.
Upon completion of the program defined by the license condition, the staff will review all relevant geological, seismological and engineering infor-mation to assure adequacy of seismic margins.
Victor Stello, Jr.
Executive Director for Operations NAME AMMELL
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CC:
Richard F. Locke, Esq.
Pacific Gas
& Electric Company Post Office Box 7442 San Francisco, California 94120 Janice E. Kerr, Esq.
California Public Utilities Commission 350 McAllister Street San Francisco, California 94102 Ms. Sandra A. Silver 660 Granite Creek Road Santa Cruz, California 95065 Mr. W. C. Gangloff Westinghouse Electric Corporation P. 0.
Box 355 Pittsburgh, Pennsylvania 15230 Managing Editor San Luis Obispo County Telegram Tribune 1321 Johnson Avenue P. 0.
Box 112 San Luis Obispo, California 93406 Mr. Leland M. Gustafson, Manager Federal Relations Pacific Gas and Electric Company 1726 M Street, N.
W.
Washington, DC 20036-4502 Dian M. Grueneich, Esq.
Edwin F. Lowry, Esq.
Grueneich
& Lowry 345 Franklin Street San Francisco, California 94102 NRC Resident Inspector Diablo Canyon Nuclear Power Plant c/o U.S. Nuclear Regulatory Commission P. 0.
Box 369 Avila Beach, California 93424 Mr. Dick Blakenburg Editor
& Co-Publisher South County Publishing Company P. 0.
Box 460 Arroyo Grande, California 93420 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 Luispo Obispo County Board of Supervisors Room 220 County Courthouse Annex San Luis Obispo, California 93401 Director Energy Facilities Siting Division Energy Resources Conservation and Development Comoission 1516 9th Street Sacramento, California 95814 Ms. Jacquelyn Wheeler 2455 Leona Street San Luis Obispo, California 93400
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CC:
Ms. Laurie McDermott, Coordinator Consumers Organized for Defense of Environmental Safety 731 Pacific Street, Suite 42 San Luis Obispo, California 93401 Mr. Joseph
- 0. Ward, Chief Radiological Health Branch State Department of Health Services 714 P Street, Office Building 88 Sacramento, California 95814 Ms. Nancy Culver 192 Luneta Street San Luis Obispo, California 93401 President California Public Utilities Commission California State Building 350 McAllister Street San Francisco, California 94102 Regional Administrator, Region Y
U.S. Nuclear Regulatory Commission 1450 Maria Lane Suite 210 Walnut Creek, California 94596 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, Vice President Nuclear Power Generation c/o Nuclear Power Generation, Licensing Pacific Gas and Electric Company 77 Scale Street, Room 1451 San Francisco, California 94106
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DISTRIBUTION UDocket File (50-275/323)
NRC PDR L PDR PD5 H. Schierling SECY (2)
B'lack J. Scinto L. Chandler B. Vogler
- Chairman, ASLB
- Chairman, ASLAP P. Narbut M. Mendonca D. Kirsch C.
Trammell G. Knighton G.
Holahan D. Crutchfield G. Bright, ASLB J.
- Harbour, ASLB B.
P. Cotter, ASLB
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