ML20006D410

Summary of 891204 Meeting W/Numarc Re Individual Plant Exam for External Events (IPEEE) Schedule & NUMARC Comments on Draft IPEEE Generic Ltr

ML20006D410
Person / Time
Issue date:	02/05/1990
From:	Bagchi G NRC - EXTERNAL EVENTS STEERING GROUP
To:	Shao L NRC
References
NUDOCS 9002130156
Download: ML20006D410 (20)

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e HEMORANDUM FOR:-

Distribution FROM:-

Goutam Bagch'i, Secretary

. External Events Steering Group

SUMMARY

OF DECEMBER 4, 1989 MEETING WITH NUMARC ON INDIVIDUAL PLANT EXAMINATION FOR EXTERNAL EVENTS (IPEEE)

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The NRC staff met with the Nuclear Management and Resources Council (NUMARC) representatives on December 4, 1989, to discuss the IPEEE schedule and NUMARC coments on the draf t IPEEE Generic Letter. is a list of meeting attendees.- The summary of the meeting is as follows, Mr. W. Rasin of NUMARC made the-leading presentation stressing the following:

-1.

IPEEE Schedule:

(a) Based on a review of the responses to the IPE generic letter on internal events, it is evident that only a few utilities plan to submit both the internal and external events examination reports-within the next three years; they plan to use probablistic risk

' assessment (PRA)methodsandnotthealternativemethods.

(b) Licensees need guidance documents prior to the issuance of the IPEEE Generic Letter.

(Mr. Shao, NRC, pointed out that a guidance document will be issued at the same time as the IPEEE GL)

(c) Licensees need schedule flexibility for the IPEEE submittal and the Accident Management Program Implementation due to resource limitations such that they could be performed sequentially.

(Dr. Murley, NRC, indicated that it is feasible to issue both.the IPEEE -

GL and its associated guidance documents and still consider a flexible schedule for. licensees to submit their IPEEE reports. Dr. Speis, NRC, indicated that prior to plant life extension and license renewal a licensee is required to close the severe accident issues for its specific plant.)

2.

A brief listing of NUMARC and NRC meetings and the subjects of discussion during the past year.

3.

Industry. position on. seismic IPEEE:

(a) The EPRI seismic hazard study provides a reasonable basis for the assessment of seismic hazards for the eastern U.S. (EUS) plants.

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(Mr. Richardson, NRC, pointed out that there was no rational basis I

for discarding LLNL's seismic hazard study.)

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(b)- The Seismicity Owners Group (S0G/EPRI) work also resolved the Charleston. issue.

(NRC staff indicated that plant specific actions steming from resolution of the Charleston Earthquake issue, which it is still working.on, will be implemented within the framework of IPEEE.)

(c) EPRI seismic margin assessment method is a justifiable approach for i

determining the seismic capacity of a plant. -

(d) Using generic plant fragility parameters and a site specific EPRI seismic hazard a uniform hazard review level earthquake can be determined and related to quantitative safety goals. This provides an adequate basis for " grouping" plants in a corponent screening level to be used in-conjunction with the EPRI seismic margin assessment method.

(The NRC staff indicated that the review level earthquake is to be used to report the seismic capacity to the NRC and does not imply any correlation = to core damage frequencies or any quantitative safety goals.)

4.

Fire IPEEE:

(a) The development of an alternative fire evaluation method and improved data bases is proceeding well with a draft report scheduled for February 1990, demonstration (probably for two plants, a PWR.

and a BWR) by June 1990, and a final report for industry use by August 1990. NUMARC will provide the draft report to the NRC staff in March to support NRC's. internal review of the IPEEE generic letter package.

(NRC staff indicated that the IPEEE generic letter will provide flexibility to allow the use of NUMARC's alternative fire evaluation method once developed and justified.)

(b)- NUMARC needs more detailed and specific documentation in the IPEEE generic letter on the disposition of and necessary responses to issues identified in Fire Scoping Study.

(Mr. Sniezek, NRC, questioned the need for providing detailed requirements in the generic letter and suggested that additional guidance could be provided in the supporting documents.)

1 (c). Containment parformance associated with fire hazard is not necessary because of the extremely low fire induced core melt probability based on industry PRA performed to date.

~(Dr. Beckner, NRC, pointed out that containment performance needs to be assessed only if significant sequences are identified and the are different from those obtained in internal events analyses.) y u

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5.

-Other Events IPEEE (a) NUMARC concurs with the staff position that the current design basis requirements (cresria for plants licensed subsequent to 1974) are conservative and can be used as a basis for screening out external 1

initiators such as high wind and external flooding.

J (b) NUMARC requested explicit statements in a staff guidance document about the estimated recurrence frequencies of the current design basis flood and tornado.

(NRC. staff agreed to provide such explicit information in the guidance document; for example, frequency of external floods when they are based on RG 1.59.)

(c). NUMARC considers it inappropriate to subsume GI-103, " Design for Probable Maximum Precipitation."

(Mr. Snierek, NRC, pointed out that the NRC has given its position in the generic letter on this subject (GL89 22).

It should be noted that the GL does not call for any.backfit and the licensees 1

should-consider the information and voluntarily take any action that 1

water on roofs.)priate for its plant such as preventing ponding of it decides appro 6.

NUMARC had the following coments on the IPEEE generic letter:

(a) More detailed and specific description of the IPEEE Scope should be 1

rovided in the guidance decument.

p(NRC' staff indicated that the guidance documents currently being developed would contain the details.)

-l (b) NUMARC was concerned that the scope of review is being expanded; e.g.,

level 1 PRA sensitivity study, relay chatter effects, and containment performance for flooding and fire.- (NRC staff does not agree. The containment issue has been addressed previously.

Seismic related issues should be trivial as explained in the guidance document.)

(c)

It is acceptable to subsume generic issues, e.g., GI-131, " Potential Seismic Interaction Involving Movable In-Core' Flux Mapping System Used in Westinghouse Plants," and GI-57, " Effects of Fire l

Protection System Actuation on Safety Related Equipment," if the j

resolution to these issues becomes obvious during the conduct of the

-l IPEEE.

(The NRC staff indicated that currently it does not intend to include GI-57 resolution through IPEEE, With respect to the movable in-core flux mapping system, the seismic walkdown by itself j

should be able to determine if a vulnerability exists and whether or notcost-effectivefixesarefeasible.)

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Mr. J. Whiteraft of NUMARC presented the highlights of its proposed seismic-examination approach. The salient point in this approach is that using generic plant fragility parameters and site specific EPRI seismic hazard, a plant-specific uniform hazard review level earthquake can be determined and related to quantitative safety goals. This point led to a significant amount of discussion about the use of plant specific hazard to perform a seismic review in lieu of a generic review level earthquake for all plants in the eastern U.S., appropriateness of the use of safety goals on a plant specific basis and ignoring the seismic hazard estimates from the NRC sponsored study by LLNL. Mr. W. Lindblad of NUMARC stated that the industry has been very -

responsive to the NRC concerns in coming up with its proposed seismic approach.

Dr. Murley, NRC, indicated that the NRC will take a close look at NUMARC proposal vis a vis the NRC review level earthquake.

The material presented by NUMARC is provided as Enclosure 2.

15l Goutam Bagchi, Secretary External Events Steering Group

Enclosures:

1.

Meeting Attendees I

2.

Presentation Material by NUMARC l

DISTRIBUTION:

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- W. Houston T. Novak'

'J Richardson G. Bagchi-J. Mitchell W. Minners E. Beckjord D. Ross

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' T. Murley -

F. Miraglia C. Seiss, ACRS

.W. Beckner -

' A. Murphy L. Reiter

. N. Chokshi -

D.Jeng G. Kelly C. McCracken.

t J. Whiteraft,- NUNARC

-J. Sniezek T. King E. Fotopoulos, Bechtel

' E. igne, ACRS.

D. Modeen,NUMARC L. Gifford,- GE/NUMARC/SAWG S. Schuhz, Yankee Atomic W. Rasin, NUMARC -

C. Reed, Commonwealth Edison B. Lindblad, NUMARC/SIWG/ Portland R. Ng, NUMARC-K. Vavrek, Westinghouse J.Chen-PDR 5

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-NUMARC/SAWG/SIWG/NRC SENIOR MANAGEMENT MEETING ON.

IPE OF EXTERNAL EVENTS i

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DECEMBER 4, 1989 ROCKVILLE, MARYLAND L

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IPE-0F EXTERNAL EVENTS SCHEDULE 0

ONLY SMALL NUMBER OF UTILITIES PLAN SUBMISSION H

0F-BOTH INTERNAL AND EXTERNAL EVENTS IPEs.WITHIN 1

NEXT 3 YEARS-THESE IPEEEs TO BE PERFORMED USING PRA g

METHODS NONE EXPECTED TO USE ALTERNATIVE EVALUATION L

METHODOLOGIES j

0 NEED' AVAILABILITY OF IPEEE NUREG DOCUMENTS PRIOR c

TO ISSUANCE OF GENERIC LETTER 0

SCHEDULE FLEXIBILITY FOR LICENSEE IPE SUBMISSIONS l

AND ACCIDENT MANAGEMENT PROGRAM IMPLEMENTATION l

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IPE OF EXTERNAL EVENTS PREVIOUS SAWG/SIWG/NRC MEETING CONCLUSIONS AND ACTION ITEMS O

STAFF WILL PROVIDE IPEEE GENERIC LETTER BY END 0F SUMMER-FOR COMMENT AND STRIVE TO ISSUE FINAL BY END OF 1989 0

NRC WILL NOT REQUIRE PRAs FOR IPEEEs (I.E., NO REQUIREMENT FOR CORE DAMAGE FREQUENCY VALUES)

O EPRI SEISMIC MARGINS METHOD IS ACCEPTARi.E WITH "SOME FINE TUNING" 0

FOLLOW-UP DIALOGUE NECESSARY TO DETERMINE

-DISPOSITION OF SANDIA FIRE RISK SCOPING STUDY ISSUES 0

INDUSTRY TO DEVELOP SIMPLIFIED FIRE EVALUATION METHODOLOGY, ALLOWING FOR STAFF INPUT AND REVIEW O

NRC AND INDUSTRY STAFF TO HAVE: FOLLOW-ON MEETING

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TO FURTHER DISCUSS METHODOLOGIES FOR SCREENING 1

AND EVALUATION OF OTHER EXTERNAL EVENTS 0

FOLLOW-ON MEETINGS DURING SUMMER T0 RESOLVE THE FOLLOWING SEISMIC ISSUES:

REVIEW LEVEL GROUND MOTION EARTHQUAKE HIGH FREQUENCY GROUND MOTION TREATMENT EASTERN SEISMICITY (I.E., CHARLESTON EARTHQUAKE)

H IPE F0R SEISMIC EVENT INDUSTRY POSITION 0-STUDIES PERFORMED ON EASTERN US PLANTS BY EPRI FOR THE SEISMICITY OWNERS. GROUP PROVIDED A REASONABLE BASIS FOR ESTABLISHING SEISMIC HAZARD IN THE EASTERN US (EPRI NP-4726) 0 THE S0G WORK ALSO RESOLVED THE EASTERN US L

SEISMICITY (CHARLESTON) ISSUE (EPRI NP-6395) 0 THE EPRI SEISMIC MARGIN ASSESSMENT METHODOLOGY IS A JUSTIFIABLE APPROACH FOR DETERMINING THE SEISMIC CAPACITY 0F A PLANT (EPRI NP-6041) 0 USING GENERIC PLANT FRAGILITY PARAMETERS AND SITE-SPECIFIC EPRI SEISMIC HAZARD, A UNIFORM HAZARD REVIEW LEVEL EARTHOUAKE CAN BE DETERMINED AND RELATED TO QUANTITATIVE SAFETY GOALS-(EPRI NP-2356-52) 0 EXCEPT FOR BRITTLE STRUCTURES-AND RELAYS, THE EFFECTS 0F HIGH FREQUENCY GROUND MOTION ARE NOT IMPORTANT TO PLANT SEISMIC PERFORMANCE (EPRI RP-2733-23)

O USE OF A REVIEW LEVEL EARTHQUAKE, MODIFIED FOR HIGH FREQUENCY GROUND MOTION, PROVIDES AN ADEQUATE BASIS FOR 'BINNING' PLANTS IN A COMPONENT SCREENING LEVEL TO BE USED IN CONJUNCTION WITH THE EPRI SEISMIC MARGIN ASSESSMENT METHODOLOGY (EPRI RP-2733-23) i

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IPE OF FIRE EVENTS 0

INTERACTIONS ON DEVELOPMENT OF ALTERNATE FIRE

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VULNERABILITY EVALUATION METN0DOLOGY AND IMPROVED DATA BASES PROCEEDING WELL DRAFT ALTERNATIVE FIRE VULNERABILITY EVALUATION METHODOLOGY AND DATA BASE REPORT i

L TO BE ISSUED FEBRUARY 1990 i

COMPLETE DEMONSTRATION 0F ALTERNATE METHODOLOGY BY JUNE 1990 l

-ISSUE FINAL METHODOLOGY AND DATA BASES FOR INDUSTRY USE BY AUGUST 1990 l

0 DISPOSITION AND NECESSARY INDUSTRY RESPONSES ON SANDIA FIRE SCOPING STUDY' ISSUES NEED MORE DETAILED AND SPECIFIC DOCUMENTATION IN IPEEE.

GENERIC LETTER

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0' IPE OF OTHER EXTERNAL EVENTS INDUSTRY POSITION o

O CONCUR WITH STAFF POSITION--CURRENT DESIGN-1 BASIS REQUIREMENTS HIGHLY CONSERVATIVE l

L CONSISTENT WITH IDCOR POSITION ALL PLANTS RECEIVING.0PERATING LICENSES L

SUBSEQUENT TO 1974 NEED DRLY CONFIRM NO L

SIGNIFICANT CHANGES AND PERFORM SITE L

WALKDOWN l

0 INDUSTRY EFFORTS TO IDENTIFY / DEVELOP ALTERNATIVE.

SCREENING METHODS NOT SUCCESSFUL o

0 REQUE11_ EXPLICIT STATEMENTS IN STAFF GUIDANCE USE REGULATORY GUIDE 1.59 T0 DEFINE LICENSING BASIS FLOOD LEVEL (I.E.,

RECURRENCE FREQUENCY OF E-5)

USE REGULATORY GUIDE 1.76 TO DEFINE LICENSING BASIS WIND VELOCITIES (I.E.,

RECURRENCE FREQUENCY OF E-7)

INAPPROPRIATE TO SUBSUME GI-103,

" DESIGN FOR PROBABLE MAXIMUM PRECIPITATION,"

(GENERIC LETTER 89-R$)XX J:

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DRAFT IPEEE GENERIC LETTER GENERAL COM4ENTS

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1 DISPOSITION 0F SANDIA FIRE RISK SCOPING l

ISSUES USE OF: INDUSTRY DEVELOPED ALTERNATIVE FIRE VULNERABILITY EVALUATION NETHODOLOGY AND IMPROVED / UPDATED DATA BASES L

0 NEED AVAILABILITY OF NUREG DOCUMENTS PRIOR TO 4

ISSUANCE OF IPEEE GENERIC LETTER 0

NEW EVALUATION SCOPE, E.G.,

LEVEL 1 PRA SENSITIVITY STUDY TO IDENTIFY l

EQUIPMENT FOR SEISMIC MARGINS METHODS INCLUSION OF RELAY CHATTER EFFECTS IN SEISMIC PRAs AND CALCULATIONS FOR BOTH-q,V EPRI AND LLNL HAZARD CURVES d

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EVALUATE FLOODING AND FIRE EFFECTS ON CONTAINMENT PERFORMANCE

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0-SUBSUMPTION OF GENERIC ISSUES, E.G.,

GI-131, " POTENTIAL SEISMIC INTERACTION...IN-

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GI-57, " EFFECTS OF FIRE PROTECTION SYSTEM

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REVIEW' LEVEL GROUND MOTION 0

HIGH FREQUENCY GROUND MOTION 1

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. PHILOSOPHY ON SEISMIC EVALUATIONS p-0 IMPLEMENTATION ACTIONS SHOULD BE BASED ON EPRI-SEISMIC HAZARD AND PLANT DESIGN BASIS O

REVIEW LEVEL GROUND MOTION SHOULD BE BASED-l ON REALISTIC ENGINEERING ANALYSIS 0-FLEXIBILITY SHOULD BE ALLOWED IN THE CH0 ICE 0F SPECTRAL SHAPE 0

HIGH FREQUENCY GROUND N0 TION IS NOT SIGNIFICANT-TO SAFETY l

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POSITION ON SEISMIC EVALUATIONS 0

STUDIES PERFORMED ON EASTERN US PLANTS BY EPRI FOR THE SEISMICITY 0WNERS GROUP PROVIDE l

A REASONABLE BASIS FOR ESTABLISHING SEISMIC 1

HAZARD IN THE EASTERN US (EPRI NP-4726) 0 THE 50G WORK ALS0-RESOLVED THE EASTERN US SEISMICITY (CHARLESTON) ISSUE (ERPI NP-6395) 1 0

THE EPRI SEISMIC MARGIN ASSESSMENT.

a METHODOLOGY IS A JUSTIFIABLE APPROACH FOR DETERMINING THE SEISMIC CAPACITY 0F A PLANT (EPRI NP-6041) 0 USING GENERIC PLANT FRAGILITY. PARAMETERS

.AND SITE-SPECIFIC EPRI SEISMIC HAZARD, A UNIFORM HAZARD REVIEW LEVEL EARTHQUAKE CAN BE DETERMINED AND RELATED.T0 QUANTITATIVE SAFETY G0ALS (EPRI RP-2356-52)-

0 EXCEPT FOR BRITTLE STRUCTURES AND RELAYS, THE EFFECTS:0F HIGH FREQUENCY GROUND MOTION ARE NOT IMPORTANT TO PLANT SEISMIC PERFORMANCE (EPRI RP-2733-23) 0 USE OF A REVIEW-LEVEL EARTHQUAKE, MODIFIED FOR:HIGH FREQUENCY GROUND MOTION, PROVIDES AN ADEQUATE BASIS FOR 'BINNING' PLANTS IN A COMPONENT SCREENING LEVEL TO BE USED IN CONJUNCTION WITH THE EPRI SEISMIC MARGIN ASSESSMENT METHODOLOGY (EPRI RP-2733-23)

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-.3-IPE FOR SEISMIC EVENTS POSITION.0N REVIEW LEVEL GROUND H0 TION 0.

USE A GENERIC CORE DAMAGE FREQUENCY OF 2E-5'FOR SEISHIC INITIATORS i

0 USE EPRI SEISMIC NAZARD'RESULTS AND GENERIC PLANT FRAGILITY PARAMETERS 0

CALCULATE A SITE-SPECIFIC REVIEW LEVEL i

EARTHQUAKE AND UNIFORM HAZARD SPECTRUM (UHS) SHAPE I

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POSITION ON HIGH FREQUENCY GROUND N0 TION 0

TRUNCATE UHS-AT GROUND NOTION DISPLACEMENTS AB0VE 0.020" AND RETURN THE SPECTRUM TO R

ZERO PERIOD ACCELERATION 0

USE.THE-RESULTING-SITE-SPECIFIC REVIEW i

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LEVEL GROUND MOTION-(RLGM) T0 DETERMINE THE GROUND MOTION BIN FOR SEISMIC MARGIN s

L ASSESSMENT l

0 USE THE GROUND MOTION BIN AS THE EVALUATION AND REPORTING LEVEL-FOR PLANT L

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fA,4a FOR RLGM AB0VE THE SSE, PERFORM A I

SEISMIC MARGIN ASSESSMENT AT 0.3 G 4

INTEGRATE USI A-46 RESOLUTION AS NEEDED i

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PROVIDE.HIGH CONFIDENCE OF LOW PROBABILITY l

0F FAILURE GROUND MOTION FOR COMP 0NENTS-BELOW THE REVIEW. LEVEL GROUND MOTION 8

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