ML16341F723
| ML16341F723 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon  |
| Issue date: | 02/27/1990 |
| From: | Page B Advisory Committee on Reactor Safeguards, STANFORD UNIV., STANFORD, CA |
| To: | Seiss C ILLINOIS, UNIV. OF, URBANA, IL, Advisory Committee on Reactor Safeguards |
| References | |
| ACRS-CT-1962, NUDOCS 9006110143 | |
| Download: ML16341F723 (6) | |
Text
ACCELERATED DISTRIBUTION DEMONS TION SYSTEM REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)
ACCESSION NBR:9006110143 DOC.DATE: 90/02/27 NOTARIZED:
NO FACIL:50-275 Diablo Canyon Nuclear Power Plant, Unit 1, Pacific Ga 50-323 Diablo Canyon Nuclear Power Plant, Unit 2, Pacific Ga AUTH.NAME AUTHOR AFFILIATION PAGE,B.M.
ACRS Advisory Committee on Reactor Safeguards RECIP.NAME RECIPIENT AFFILIATION SIESS,C.P.
ACRS Advisory Committee on Reactor Safeguards
SUBJECT:
Comments on 900129-30 NRC/PGGE meetings re plant.
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DEPARTitENT OF GEOLOGY School of Earth Sciences Stanford, California 94305-2115 STAZ%FSRDiiin p.
'. 3..
UNIVERSITY QT-l@Z ygfc w)zi/e TELEPHONE: (415) 723-2537 TELEX: 345402 STANFRD STNU FAX: (415) 725-2199 Dr. Chester P. Siess 3110 Civil Engineering
@MIfi.'niversity of Illinois Urbana, IL 61801 i%bruary 27, 1990
Dear Chet:
On January 29 and 30,'
attended the NRC-PG
& E meetings regarding the Diablo Canyon Nuclear Power Plant.
These meetings were well
- prepared, were conducted informally, and generated much discussion among the PG
& E people and various experienced consultants.
The main purpose of the meetings was to display informative offshor seismic reflection profiles relevant to the Hosgri fault, alongside PG
& E interpretat-'ons, in order to allow close scrutiny and criticism of the data,and its possible meaning.
The meeting was different from preceding ones in that PG
& E systematically provided a virtually complete set of un-doctored profiles for the Hosgri fault and environs for the entire coast from San Simeon to the latitude of Lompoc, and did so by posting on the walls of the conference room the data from north to south, reduced to a common scale.
The interpreted cross sections were at the same scale, had uniform symbols and colors, and showed varying degrees of confidence for the location and dip of faults.
The attendees did not sit at a table, but formed spon-taneous discussion groups within touching distance of the exhibits.
There were lively arguments'nd differences of opinion.
Some differences remained to the end, but there were substantial points of agreement, including the following:
1.
The Hosgri fault is not well defined in the lower parts of the reflection profiles.
- 2. It appears to be very well located near the sea floor (Jim Crouch disagrees).
3.
The upper, well-located part of the fault is steeply-,dipping or vertical (Crouch has reservations).
- 4. There are reverse faults alongside the main fault.
- 5. The Hosgri fault is a pronounced structural boundary, separating two'omains of very different structural aspect.
Some of the attendees who rely on the reflection profiles entirely and who discount the geologic evidence still think that the Hosgri fault is basically a reverse or thrust fault, but the majority of those present seemed to agree with the interpretation of the PG
& E team; i.e., the fault may have a reverse component, but it is mainly a strike-slip feature.
As you know, thrust faults tend to show well in seismic profiles, but strike-slip faults (ineiuding the San Andreas) are usually poorly delineated.
90062101~
DR
~t Rp S'00227 C~ >5'62 PDC DESIGMTED ORIGINAL ftI Certified ~
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In summary, the meeting probably did not change anything, but it was applauded by all parties. I think it built confidence in the latter-day
- openness, scientific competence, and immense effort of the PG 6
E team.
I regret the tardiness of this report.
My travel schedule has been intensive.
Vith all good wishes, Ben)amfn M. Page ACRS consultant cc Elpidio Igne
C J.'\\