ML17095A506
| ML17095A506 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon  |
| Issue date: | 05/27/1986 |
| From: | Schierling H Office of Nuclear Reactor Regulation |
| To: | Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML16342B210 | List: |
| References | |
| REF-GTECI-A-41, REF-GTECI-SC, TASK-A-41, TASK-OR NUDOCS 8606030376 | |
| Download: ML17095A506 (16) | |
Text
~ PQ REMI P0 Op UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, O. C. 20555 May 27, 1986 Docket Nos.
50-275 and 50-323 LICENSEE: Pacific Gas and Electric Company (PG&E)
FACILITY: Diablo Canyon Nuclear Power Plant, Units 1 and 2
SUBJECT:
MEETING
SUMMARY
LONG TERM SEISMIC PROGRAM {LTSP)
On March 11 and 12, 1986 the NRC staff and its consultants met with Pacific Gas and Electric Company (PGEE), licensee for the Diablo Canyon Plant and its consultants regarding the Long Term Seismic Program (LTSP).
This was the first semi-annual LTSP meeting in accordance with the license condition in the Unit 1
full power license.
Enclosures 1,
2 and 3 are the meeting notice, list of attendees and agenda for the meeting, respectively.
The purpose of the meeting was for PG&E to provide an overview of the LTSP status and to present details on the analytical studies, data
- base, and preliminary results from its Scoping Study (Phase II of the LTSP), which had been provided to the staff in a submittal dated January 30, 1986 (PG&E Letter DCL-86-022).
L. Cluff (PG&E) described briefly (see Enclosure
- 3) the history of the initial phase of the LTSP (Phase I), the basis for the Scoping Study (Phase II), how the final Phase III of the program will consider and be based on the Scoping
. Study, and how the fle'xibilityof the overall LTSP will be maintained to accommodate potential changes and maintain a real.istic schedu'le.
Detailed presentations by PG&E and its consultants were made on the following subjects using extensive viewgraphs as indicated:
Phase II Studies - Methods Used to Identify Significant Technical Considdrations (Enclosure 4)
Phase III, Geology/Seismology/Geophysics
- Including Seismic Network (Enclosure 5)
Phase II - Geology/Seismolgy/Geophysics (Enclosure 6)
LTSP Ground Motion Program (Enclosure 7)
Seismic Hazard Results (Enclosure 8)
Evaluation of Soil-Structure Interaction Effects (Enclosure 9)
Phase II Probabilistic Risk Assessment, Parts 1 and 2 (Enclosure 10)
Fragility Evaluation
{Enclosure 11)
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8 gf 7 y 27, 1986 The results of the Scoping Study included the geologic and geophysical aspects of the site, 'mechanisms to translate this information into the seismic hazard to the site by deterministic and analytical
- means, response of structures to ground motion by soil-structure interaction techniques, and probabilities of structure and/or equipment failures.
During the meeting the staff raised numerous questions to which PGSE provided detailed answers.
The staff summarized those questions at the conclusion of the meeting in the following comments:
l.
Areas within seismically active zones which historically have exhibited little or no seismic activity, referred to as "seismic gaps",
could produce larger seismic events.
When available seismic data are used to determine the likelihood of earthquake recurrence the lack of such data need also be considered.
2.
Consideration should be given to the possibility of a continuous fault system including the Little Pine - Foxen Canyon fault and the Santa Maria River fault extending north-west toward the Diablo Canyon site.
3.
The actual data on which the deterministic ground motion estimates (50th and 84th percentile) are based for specific scenarios and the specific contributions of these scenarios to core melt probability should be identified.
.4.
It is not clear whether the seismic reflection profiles studies by
- Crouch, Bachman and Shay will be considered.
These are the basis for the hypothesis that the Hosgri Fault near the Diablo Canyon Plant and other faults along central California are principally thrust faults listric to a master decollment.
5.
At this stage of the LTSP the Hosgri Fault is considered to be the controlling structure for the maximum earthquake significant to the site.
In making that determination early in the program there is always a possibility that other tectonic structures might be overlooked which could be significant to the site because of their proximity to the plant or style of deformation.
6.
Because the Hosgri Fault is considered to be the controlling structure it is important that information, including slip rate, down dip geometry, rupture width, and proximity to the site be considered; adequate consideration should be given to uncertainties.
Specific characteristics of earthquakes and faults in the site region such as amplification, sense of slip, width of the rupture zone, attitudes of faults, should be evaluated.
Additional information about tectonic structures in the site area might be necessary.
ih l(
Ma 27, 1986 7.
8.
9 The difficulty.of identifying active faults in a melange terrance such as 'that underlain by the Franciscan Formation east of the site should be kept in mind.
Ground-motion frequencies above 10 Hertz should be examined closely in light of the recent experience at the Perry Nuclear Power Plant during the January 31, 1986 Ohio earthquake.
The ground motion studies should carefully consider, in addition to those subjects mentioned in the presentation, the locations of structures with respect to the topography such as proximity to sea cliffs and slopes behind the plant.
Site recordings, structural response
- data, and other site specific information should be compared with pertinent records throughout California.
Extensive high quality seismic records for California are available.
10.
12.
There is no obvious correlation between vertical and horizontal acceleration.
A comparable effort should be made to assess vertical acceleration as is being made regarding horizontal acceleration.
There should be a
common understanding among the LTSP participants, in particular seismologists and engineers, about the way horizontal acceleration is considered in the structures,
- systems, and components (e.g.,
average or maximum).
In addition to the. low level earthquake data recorded at the site to validate the analytical models and computer codes, high level earthquake recordings should be obtained, if'possible, for verification.
18.
19.
The standard deviation associated with the ground motions is important and should be utilized.
The basis for the weighting factors used on the logic trees should be well documented.
Although the CLASSI and SASSI codes have shown good comparisons for very low levels of ground motion, their ability to predict realistic engineering results at high levels of ground motion should be demonstrated.
The impact on fragility curves for variations in the vertical component of ground motion should be determined.
20.
It appears, based on the presentation, that in the PRA and fragility consideration of the Scoping Study the loss of component cooling water (CCW) sequence may have been treated in a non-conservative
- manner, taking credit for successful blind shutdown.
Based on the presentations by PG8E and the ensuing discussions, the staff considered the LTSP to be a well thought-out program that involves PGRE individuals and consultants of impressive quality.
The staff commented
-4 Ma 27 > 1986 that the quality of the PGRE presentations and the detailed information presented (Enclosures) far exceed that provided in the Scoping Study Report of January 1986 and in the quarterly reports.
The staff stated there is a need that data and documentation be provided for the NRC staff as the program moves along in order for the staff to review the information in more detail and for other individuals, not present at
- meetings, to also have access to the information.
While meetings such as this provide an excellent opportunity to present and discuss information, documen-tation is needed for detailed and independent evaluation.
It is important that the bases for key decisions that may turn out to be irreversible be made known to the staff before such final decisions are made.
For example, a break down is needed for the various scenarios, including supporting data, assumptions considered and the significant contributors.
The staff recognizes that the progress of the program could be impacted if frequent detailed reports were prepared by PGIEE.
The staff requested PGImtE to provide a schedule for the completion of specific LTSP activities.
Submittal of detailed reports might be an appropriate mechanism of documentation.
In addition, the staff will consider the feasability to have more frequent meetings or workshops on specific subjects.
The staff also requested that PGIIE clearly identify all additions and deletions from the LTSP as approved by the staff.
At the conclusion of the meeting the staff requested its consultants to provide further comments on the meeting.
Attached as Enclosures 12 and 13 are letters from K. Campbell and R.
Brown of the USGS, dated March 19 and April 4, respectively.
Enclosures:
As stated
/s/HSchierling Hans E. Schierling, Senior Project Manager PWR Project Directorate No.
3 Division of PWR Licensing-A, NRR cc w/enclosures:
See next page n
PAD83 HSchier ng/pws 05/2 P/86
h' E
7
Mr. J.
D. Shiffer Pacific Gas and Electric Company Diablo Canyon CC:
Philip A. Crane, Jr.,
Esq.
Pacific Gas 5 Electric Company Post Office Box 7442 San Francisco, California 94120 Mr. Malcolm H. Furbush Yice President - General Counsel Pacific Gas 5 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 Mr. Frederick Eissler, President Scenic Shoreline Preservation Conference, Inc.
4623 More Mesa Drive Santa Barbara, California 93105 Ms. Elizabeth Apfelberg 1415 Cozadero San Luis Obispo, California 93401 Mr. Gordon A. Silver Ms. Sandra A. Silver 1760 Alisal Street San Luis Obispo, California 93401 Harry M. Willis, Esq.
Seymour 5 Willis 601 California Street, Suite 2100 San Francisco, California 94108 Mr. Richard Hubbard MHB Technical Associates Suite K
1725 Hamilton Avenue San Jose, California 95125 Glenn 0. Bright Administrative Judge Atomic Safety and Licensing Board U.S. Nuclear Regulatory Commission Washington, DC 20555 NRC Resident Inspector Diablo Canyon Nuclear Power Plant c/o US Nuclear Regulatory Commission P. 0.
Box 369 Avila Beach, California 93424 Ms.
Raye Fleming 1920 Mattie Road Shell Beach, California 93440 Joel
- Reynolds, Esq.
John R. Phillips, Esq.
Center for Law in the Public Interest 10951 West Pico Boulevard Third Floor Los Angeles, California 90064 Mr. Dick Blankenburg Editor
& Co-Publisher South County Publishing Company P. 0.
Box 460 Arroyo Grande, California 93420 Bruce Norton, Esq.
- Norton, Bur ke, Berry 8 French, P.C.
2002 E. Osborn Road P. 0.
Box 10569 Phoenix, Arizona 85064 Mr.
W. C. Gangloff Westinghouse Electric Corporation P. 0.
Box 355 Pittsburgh, Pennsylvania 15230 David F. Fleischaker, Esq.
P. 0.
Box 1178 Oklahoma City, Oklahoma 73101 Managing Editor San Luis Obispo County Telegram Tribune 1321 Johnson Avenue P. 0.
Box 112 San Luis Obispo, California 93406 Dr. Jerry Harbour Administratiave Judge Atomic Safety and Licensing Board U.S. Nuclear Regulatory Commission Washington, DC 20555
0
Pacific Gas 5 Electric Company Diablo Canyon CC:
Arthur C. Gehr, Esq.
Snell
& Wilmer 3100 Valley Center Phoenix, Arizona 85073 Mr. Leland M. Gustafson, Manager Federal Relations Pacific Gas 5 Electric Company 1726 M Street, N.W.
Suite 1100 Washington, DC 20036-4502 Regional Admini s trator, Regi on V
U.S. Nuclear Regulatory Commission 1450 Maria Lane Suite 210 Walnut Creek, California 94596 Michael J.
Strumwasser, Esq.
Spe'cial Counsel to the Attorney General State of California 3580 Wilshire Boulevard, Suite 800 Los Angeles, California 90010 Mr. Tom Harris Sacramento Bee 21st and 0 Streets Sacramento, California 95814 Mr. H. Daniel Nix California Energy Commission 1516 9th Street, MS 18 Sacramento, California 95814 Lewis Shollenberger, Esq.
US Nuclear Regulatory Commission Region V
1450 Maria Lane Suite 210 Walnut Creek, Cali fornia 94596 Ms.'ancy Culver 192 Luneta Street San Luis Obispo, California 93401 Dr. R.
B. Ferguson Siera Club - Santa Lucia Chapter Rocky Canyon Star Route Creston, California 93432 Mr. Thomas Devine Government Accountability Project Institute for Policy Studies 1901 gue Street, NW Washington, DC 20009 Chairman San Luis 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 Commission 1516 9th Street Sacramento, California 95814 President California Public Utilities Commission California State Building 350 McAllester Street San Francisco, California 94102 Mr. Joseph
- 0. Ward, Chief Radiological Health Branch State Department of Health Services 714 P Street, Office Building 88 Sacramento, California 95814 Ms. Jacquelyn Wheeler 2455 Leona Street San Luis Obispo, California 93400 Ms. Laurie McDermott, Coordinator C.O.D.E.S.
Consumers Organized for Defense of Environmental Safety 731 Pacific Street, Suite 842 San Luis Obispo, California 93401 B. Paul Cotter, Jr.,
Chairman Administrative Judge Atomic Safety and Licensing Board U.S. Nuclear Regulatory Commission Washington, DC 20555
V
MEETING
SUMMARY
DISTRIBUTION 3
cket or Centeral File RC PDR Local PDR PAD-3 RDG ORAS H. Denton R. Ballard J. Milhoan F.
Rosa C. Berlinger V. Benaroya E. Rossi D. Crutchfield G. Lainas S.
Varga Project Manager - H. Schierling OELD E. Jordan B. Grimes J. Partlow (Emet gency Preparedness)
ACRS (10)
S.
Donovan Plant Service List C.
Vogan Resident Inspector Regional Administrator NRC Partici ants I. Alterman
~
S.
Brocoum R.
Brown (USGS)
A. 'Buslik K. Campbe11 (USGS)
'.E. Chelliah, F. Congell, N.
Chokshi'.
Giese-Koch D. Jeng H. McGurren R'. McMullen, L. Ong M. Reich (BNL).
L. Reiter E. Rossi J.
Savy (LLNL)
D.
Slemmons (U of Nevada)
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ENCLOSURES 1.
Meeting Notice 2.
List of Attendees 3.
Agenda and Background 4.
Phase II - Methods Used to Identify Significant Technical Considerations 5.
Phase III - Geology/Seismology/Geophysics Tastes 6.
Phase II - Geology/Seismology/Geophysics 7.
LTSP Ground Motion Work Plan 8.
Seismic Hazard Results 9.
Evaluation of Soil-Structure Interaction Effects 10.
Phase II Probabilistic Risk Assessment 11.
Fragility Evaluation 12.
Letter from K.
W. Campbell
{USGS) to L. Reiter (NRC) dated March 19, 1986 13.
Letter from R.
D. Brown (USGS) to H. Schierling (NRC) dated April 4, 1906