NUREG-1447, Summary of 920917 Meeting W/Util in Rockville,Md Re Rept to Be Submitted by Util on IPE of External Events.Ipe Will Be stand-alone Document That Meets Format of NUREG-1447.List of Attendees & Viewgraphs Encl

Summary of 920917 Meeting W/Util in Rockville,Md Re Rept to Be Submitted by Util on IPE of External Events.Ipe Will Be stand-alone Document That Meets Format of NUREG-1447.List of Attendees & Viewgraphs Encl

ML16341G728
Person / Time
Site:	Diablo Canyon
Issue date:	10/27/1992
From:	Rood H Office of Nuclear Reactor Regulation
To:	Office of Nuclear Reactor Regulation
References
RTR-NUREG-1447 TAC-M83614, TAC-M83615, NUDOCS 9210290253
Download: ML16341G728 (42)

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UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555 October 27, 1992 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

SUMMARY

OF SEPTEMBER 17, 1992 PUBLIC MEETING TO DISCUSS THE REPORT TO BE SUBMITTED BY PG&E ON THE INDIVIDUALPLANT EXAMINATION OF EXTERNAL EVENTS (IPEEE)

FOR DIABLO CANYON (TAC NOS.

M83614 AND M83615)

On September 17, 1992, the NRC staff met with the Pacific Gas and Electric Company (PG&E or the licensee) in Rockville, Maryland to discuss the above subject.

Attendees at the meeting are given in Enclosure 1.

Slides presented by PG&E at the meeting are given in Enclosure 2.

The PG&E presentation summarized the methodology to be used for their IPEEE submittal, which is scheduled to be submitted in June 1994.

The licensee presented several topics for discussion.

They included the general approach that PG&E plans to use for the Diablo Canyon IPEEE report, a

review of the nine major issues pertaining to IPEEE requirements, a summary of the Long Term Seismic Program (LTSP) probabilistic risk analysis (PRA) previously conducted by the licensee, and an identification of the additional analysis needed for the IPEEE in areas not covered by the LTSP PRA.

The licensee stated that the Diablo Canyon IPEEE report will be a "stand alone" document that meets the format of Appendix C of NUREG-1447, "Procedural and Submittal Guidance for the Individual Plant Examination of External Events

( IPEEE) for Severe Accident Vulnerabilities."

However, the Diablo Canyon IPEEE report will reference the LTSP PRA where applicable.

PG&E plans to use the existing seismic hazard curves from the

LTSP, and does not plan to conduct new seismic plant walkdowns in addition to those previously conducted for the LTSP.

In response to a staff question, PG&E stated that seismically induced fires will be evaluated and "fire walkdowns" will be conducted for the IPEEE report.

The staff questioned the licensee on the effect of seismically induced relay chatter on containment isolation.

The licensee agreed that this will be addressed in the IPEEE analysis.

The licensee was also questioned on recent issues concerning the use of Thermo-Lag insulating materials.

The licensee 9210290253 921027 PDR ADOCK 05000275 P

'DR

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Pacific Gas and Electric Company 2

stated that it plans to address the NUREG/CR-5088 issues in the IPEEE analysis.

Potential problems with salt water systems and the circulating water system concerning pipe wall thinning were also discussed.

The licensee stated that this phenomena is currently being evaluated, and the results of this study will be used to determine how pipe thinning will be addressed in the IPEEE report.

Enclosures:

1. Attendees 2.

PG&E Viewgraphs cc w/enclosures:

See next page Harry R

d, Senior Project Manager Project Directorate V

Division of Reactor Projects III/IV/V Office of Nuclear Reactor Regulation

C

Pacific Gas and Electric Company Diablo Canyon CC:

NRC Resident Inspector Diablo Canyon Nuclear Power Plant c/o U.S. Nuclear Regulatory Commission P. 0.

Box 369 Avila Beach, California 93424 Dr. Richard Ferguson, Energy Chair Sierra Club California 6715 Rocky Canyon

Creston, California 93432 Hs.

Sandra A. Silver Mothers for Peace 660 Granite Creek Road Santa Cruz, California 95065 Hs. Jacquelyn C. Wheeler 3303 Barranca Court San Luis Obispo, California 93401 Managing Editor The County Telegram Tribune 1321 Johnson Avenue P. 0.

Box 112 San Luis Obispo, California 93406 Chairman San Luis Obispo County Board of Supervisors Room 370 County Government Center San Luis Obispo, California 93408 Christopher J.

Warner, Esq.

Pacific Gas

& Electric Company Post Office Box 7442 San Francisco, California 94120 Hr. Hank Kocol Radiologic Health Branch State Department of Health Services Post Office Box 942732 Sacramento, California 94234 Regional Administrator, Region V

U.S. Nuclear Regulatory Commission 1450 Maria Lane, Suite 210 Walnut Creek, California 94596 Hr.'eter H. Kaufman Deputy Attorney General State of California 110 West A Street, Suite 700 San

Diego, Cal iforni a 92101 Ms. Nancy Culver 192 Luneta Street San Luis Obispo, California 93401 Michael H. Strumwasser, Esq.

Special Assistant Attorney General State of California Department of Justice 3580 Wilshire Boulevard, Room 800 Los Angeles, California 90010 Hr. Gregory H. Rueger Nuclear Power Generation, B14A Pacific Gas and Electric Company 77 Beale Street, Room 1451 P.O.

Box 770000 San Francisco, California 94177 Diablo Canyon Independent Safety Committee ATTN:

Robert T. Wellington, Esq.

Legal Counsel 857 Cass Street, Suite D

Monterey, California 93940

Se tember 17 1992 PG&E IPEEE Meetin List of Attendees Enclosure 1

Charles Ader John T.

Chen Nilesh Chokshi Thomas Leserman Y. Justin Liu Jocelyn Mitchell Terry Nelson Christopher Regan Harry Rood Robert Rothman Bimal Sarkar Phyllis Sobel David Sokolsky Raymond Thierry Duke Wheeler ORGANIZATION NRC/RES/SAIB NRC/RES/SAIB NRC/RES/SSEB PG&E PG&E NRC/RES/SAIS PG&E NRC/NRR/DONRR NRC/NRR/PD5 NRC/NRR/ESGB PG&E NRC/NRR/ESGB PG&E PG&E NRC/RES/SAIB

~

~

Enclosure 2

PACIFIC GAS AND ELECTRIC COMPANY PRESENTATION TO THE NRC ON THE IPEEE SEPTEMBER 17, 1992 dd01

IPEEE INTRODUCTION Purpose Oescribe PG8 E's approach for performing IPEEE Key Points

~

Present proposed report approach

~

Review IPEEE requirements (9 issues)

~

Summarize LTSP analysis

~

identify additional analyses PG&E plans as part of IPEEE

IPEEE MEETING Presentation format

~

IPEEE report

~

Long-term seismic program history

~

Seismic analyses

~

Fire analysis

~

"Other" external events

~

Conclusions

IPEEE REPORT The general approach for the report will be to

~

Provide complete response to information requested following format in NUREG-1407, Appendix C

~

Reference additional detailed information in the LTSP

LONG-TERM SEISMIC PROGRAM HISTORY November 1984 NRC license condition, 4 elements

~

Evaluate geologic and seismic data

~

Evaluate maximum magnitude of the earthquake

~

Evaluate ground motion

~

Utilize PRA* and deterministic studies to assure adequacy of seismic margin July

1988, submitted final report June

1991, SSER 34 issued

• PRA included internal and external events and Level 1

scope

SEISMIC HAZARDS ANALYSIS IPEEE requirement

~

Define seismic hazard

~

Perform sensitivity studies to determine effect of hazard uncertainty on seismic PRA sequences LTSP analysis

~

Site specific seismic source identification

~

Uncertainty treated by developing family of hazards curves Proposed additional analysis

~

None -- use existing hazards curves

/

SEISMIC FRAGILITIES IPEEE requirement

~

Determine plant, dominant-sequence, component level fragiiities, and (optional) HCLPFs LTSP analysis

~

Component and plant level fragilities and component HCLPFs developed

~

Sensitivity studies performed to identify dominant risk contributors on PRA Proposed additional analysis

~

None -- utilize fragilities determined for LTSP

SEISMIC WALKDOWNS IPEEE requirement

~

Perform supplementary walkdown in conformance with EPRI NP-6041, revision 1

LTSP and other programs

~

LTSP seismic walkdowns predate EPRI NP-6041;

however, walkdowns meet the objective of EPRI NP-6041

~

NRC and their consultants conducted LTSP walkdowns

~

Multiple walkdowns performed for systems interactions,

Hosgri, and IDVP programs provide high confidence that as-built conditions are reflected in plant seismic evaluations Proposed additional analysis

~

None -- previous plant walkdowns meet intent of IPEEE requirements

J

RELAY CHATTER IPEEE requirement

~

Assess relay chatter effects on risk LTSP analysis

~

Relay chatter was studied and explicitly considered in seismic probabilistic risk analysis Proposed additional analysis

~

None relay chatter assessed in LTSP

NONSEISMIC FAILURES/HUMANACTIONS 1PEEE requirement

~

Nonseismic failures and human actions that might affect seismic sequences should be defined based on internal events analysis LTSP analysis

~

The seismic PRA explicitly considered nonseismic failures and human actions

~

Effect of seismic acceleration level on human action failure rates was considered Proposed additional analysis

~

None -- utilize existing seismic PRA models

SOIL LIQUEFACTION IPEEE requirement

- ~

The potential for soil liquefaction and associated effects on the plant need to be examined for some sites LTSP analysis

~

Not applicable (rock site)

Proposed additional analysis

~

None

SEISMIC CONTAINMENT PERFORMANCE IPEEE requirement

~

Perform a seismic containment performance analysis of containment integrity, containment isolation and bypass LTSP analysis

~

Focused on Level 1

PRA Evaluated containment for gross seismic failure and failure of selected containment systems Proposed additional analysis

~

Additional analysis to be performed for containment isolation, bypass and penetrations to meet IPEEE requirements dds12

~

~

FIRE ANALYSIS IPEEE requirement

~

Use of existing fire PRA is acceptable provided it reflects the current as-built and as-operated status of the

plant, and the potential deficiencies identified in NUREG/CR-5088 are addressed LTSP analysis

~

Fire PRA used NVREG/CR-2300 methodology and relied on expert judgement Proposed additional analysis

~

Address NUREG/CR-5088 potential deficiencies

~

Review Appendix R update for. impact on fire PRA

J V

"OTHER" EXTERNAL EVENTS IPEEE requirement

~

Assess the following "other" external events High winds and tornadoes External floods Transportation and nearby facility accidents Plant unique external events

"OTHER" EXTERNAL EVENTS cont'd LTSP analysis

~

A PRA for "other" external events was performed 47 external events reviewed Screening process used Proposed additional analysis

~

None --

LTSP evaluated specified events

1

CONCLUSIONS Most of the IPEEE requirements are satisfied by the LTSP PG&E will perform additional analysis as necessary to meet remaining IPEEE requirements PG&E will submit IPEEE Report by June 1994 consistent with NUREG-1407 Appendix C format

rl V.

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Paci fic Gas and El ectri c Company October 27, 1992 stated that it plans to address the NUREG/CR-5088 issues in,the IPEEE analysis.

Potential problems with salt water systems and the circulating water system concerning pipe wall thinning were also discussed.

The licensee stated that this phenomena is currently being evaluated, and the results of

'his study will be used to determine how pipe thinning will be addressed in the IPEEE report.

e Original signed by Harry Rood, Senior Project Hanager Project Directorate V

Division of 'Reactor Projects III/IV/V Office of Nuclear Reactor Regulation

Enclosures:

l. Attendees 2.

PG&E Viewgraphs cc w/enclosures:

See next page DISTRIBUTION Qlo.cket Fi.l.ed PDV Reading File

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