ML18153C971

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Summary of 911121 Meeting W/Licensee in Rockville,Md Re Reanalysis of Internal Flooding to Quantify Conservatism in Original Internal Flooding Analysis & Licensee Assessment of Other Flood Initiators,Completed Activities & Future Plans
ML18153C971
Person / Time
Site: Surry  
Issue date: 04/14/1992
From: Buckley B
Office of Nuclear Reactor Regulation
To:
Office of Nuclear Reactor Regulation
References
NUDOCS 9204200118
Download: ML18153C971 (30)
v • d • e


Text

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Docket Nos. 50-280 and 50-281 April l 4, l 99

  • DISTRIBUTION:

See next page LICENSEE: Virginia Electric and Power Company FACILITY: Surry Power Station, Units 1&2

SUBJECT:

MEETING

SUMMARY

OF NOVEMBER 21, 1991 A meeting was held with the representatives of Virginia Electric and Power Company (VEPCO) and the NRC staff in Rockville, Maryland on November 21, 1991.

During the meeting, VEPCO representatives discussed their reanalysis of internal flooding to quantify the conservatism in the original internal flooding analysis as described in their August 30, 1991, Individual Plant Examination report. Also discussed were VEPCO's assessment of other flood initiators, and completed activities and future plans. Meeting handouts and a list of attendees are enclosed.

Enclosures:

1.

List of Attendees

2.

Meeting Handout cc w/enclosures:

See n~xt page OFFICE NAME OFFICIAL R CORD COPY FILENAME: SU112191.MTS 9204200118 920414 PDR

  • ADOCK 05000280 p

PDR

/sf Bart C. Buckley, Sr. Project Manager Project Directorate 11-2 Division of Reactor Projects - 1/11 Office of Nuclear Reactor Regulation Ri~~i'TD

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e Virginia Electric and Power Company cc:

Michael W. Maupin, Esq.

Hunton and Williams Post Office Box 1535 Richmond, Virginia 23212 Mr. Michael R. Kansler, Manager Surry Power Station Post Office Box 315 Surry, Virginia 23883 Senior Resident Inspector Surry Power Station U.S. Nuclear Regulatory Commission Post Office Box 166, Route 1 Surry, Virginia 23883 Mr. Sherlock Holmes, Chairman Board of Supervisors of Surry County Surry County Courthouse Surry, Virginia 23683 Dr. W. T. Lough Virginia State Corporation Commission Division of Energy Regulation Post Office Box 1197 Richmond, Virginia 23209 Regional Administrator, Region II U.S. Nuclear Regulatory Commission 101 Marietta Street N.W., Suite 2900 Atlanta~ Georgia 30323 C.M.G. Buttery, M.D., M.P.H.

State Health Commissioner Office of the Commissioner Virginia Department of Health P.O. Box 2448 Richmond, Virginia 23218 Surry Power Station Attorney General Supreme Court Building 101 North 8th Street Richmond, Virginia 23219 Mr. E. Wayne Harrell Vice President - Nuclear Services Virginia Electric and Power Co.

5000 Dominion Blvd.

Glen Allen, Virginia 23060 Mr. J. P. O'Hanlon Vice President - Nuclear Operations Virginia Electric and Power Company 5000 Dominion Blvd.

Glen Allen, Virginia 23060 Mr. Martin Bowling Manager - Nuclear Licensing Virginia Electric and Power Company 5000 Dominion Blvd.

Glen Allen, Virginia 23060 Mr. W. L. Stewart Senior Vice President - Nuclear Virginia Electric and Power Company 5000 Dominion Boulevard Glen Allen, Virginia 23060

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DISTRIBUTION LIST FOR MEETING

SUMMARY

OF NOVEMBER 21, 1991

  • oocket Fi 1 e Pl22 PDII-2 RDG File JPartlow Glainas BBuckley OGC AThadani AGibson JShackel ford RCampe EButcher KParczewski CMcCracken ADummer DHouston JWechselberger NRC & Local PDRs TMurley/FMiraglia SVarga HBerkow DMiller EJordan FCongel WBeckner JSchiffgens JTatum HNPastis JKopeck GHubbard BLeFave HVanderMolen

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ENCLOSURE 1 LIST OF ATTENDEES FOR THE SURRY IPE MEETING OF:

November 21, 1991 NAME:

AFFILIATION:

B. Buckley NRC/NRR H. Berkow NRC/NRR G. Lainas NRC/NRR

s. Varga NRC/NRR F. Miraglia NRC/NRR F. Congel NRC/NRR A. Gibson NRC/RI I
w. Beckner NRC/NRR J. Shackelford NRC/RII J. Schiffgens NRC/NRR R. Campe NRC/NRR J. Tatum NRC/NRR T. Lough State Corporation Commission
w. Ruberry Richmond Times E. Butcher NRC/NRR H. N. Pastis RES/IPE (Detailed)

K. Parczewski NRC/NRR/EMCB J. Kopeck GPA C. Baab Virginia Power R. Ng NUMARC H. M. Fonticella Virginia Power D. M. Bucheit Virginia Power C. McCracken NRR/SPLB G. Hubbard NRR/SPLB D. Stellfox McGraw Hill/Nodeonics Week A. Dummer SPLB/DST/NRR B. LeFave SPLB/DST/NRR D. Houston NRC/ACRS H. VanderMolen NRC/RES/PRAB A. Price Virginia Power/Surry M. L. Bowling Virginia Power

w. L. Stewart Virginia Power F. Mpore Virginia Power R. M. Berryma 11 Virginia Power L. N. Hartz Virginia Power D. Cohn Washington Post J. Wechselberger NRC/OEDO

PICLf'JSURE 2 STATUS UP*DATE ON SURRY IPE / INTERNAL FLOODING NOVEMBER 21, 1991

  • e

I INTRODUCTION AND CURRENT STATUS*

e VIRGINIA POWER

.e W. L. STEWART SENIOR VICE PRESIDENT - NUCLEAR

  • AGENDA

. INTRODUCTION AND CURRENT STATUS

. REANALYSIS OF INTERNAL FLOODING TO

  • QUANTIFY CONSERVATISM IN ORIGINAL INTERNAL FLOODING ANALYSIS ASSESSMENT OF OTHER FLOOD INITIATORS REVIEW OF COMPLETED ACTIVITIES, FUTURE PLANS, AND CONCLUSIONS W. L. STEWART R. M. BERRYMAN.

M. L. BOWLING

  • M. L. BOW.LING -

INTRODUCTION SEVERAL PHYSICAL ENHANCEMENTS WHICH SIGNIFICANTL V REDUCE THE PROBABILITY FOR

MADE INTERNAL FLOODING REANAL VSIS IDENTIFIED

. SUBSTANTIAL CONSERVATISM IN THE ORIGINAL*

ANALYSIS

  • e e

INTERNAL FLOODING ANALYSIS OVERVIEW

  • ORIGINAL ANAL VSIS ORIGINAL ANAL VSIS/CURRENT PLANT CONFIGURATION CREDIT TAKEN FOR

- EX.PANSION JOINT REPLACEMENT AND MOV

. REPLACEMENT/SOLT INSPECTION

- 7 OF 9 SUMP PUMPS OPERABLE

. - CHARGING PUMP CUBICLE DRAIN LINE BACKFLOW PREVENTION DEVICE INSTALLATION

. - EXPANSION JOINT SHIELD INSTALLATION.

INTERNAL FLOODING REANAL VSIS CDF (PER YR) **

1.1 E-3 9.9E-5

  • 5.1 E-5
e.

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REANALYSIS OF INTERNAL FLOODING'* *

  • MANAGER - NUCLEAR ANALYSIS AND FUEL*

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INTERNAL FLOODING REANALYSIS THE PURPOSE OF THE REANALYSIS WAS TO QUANTIFY THE CONSERVATISM IN THE ORIGINAL ANAL VSIS,

THIS OVERVIEW WILL.PRESENT

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  • -
  • METHODOLOGY FOR' THE ORIGINAL ANAL VSIS AND THE REANALYSIS SIGNIFICANT DIFFERENCES BETWEEN THE ORIGINAL ANAL VSIS AND THE REANALYSIS ESTIMATE OF CONSERVATISM IN THE ORIGINAL ANAL VSIS COMPARISON OF RESULTS FROM THE*

ORIGINAL ANAL VSIS TO THE REANALYSIS*.

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. ORIGINAL FLOODING ANALYSI.S APPROACH FOR THE TURBINE BUILDING FLOODING DATA COMPILED FOR CW AND SW SYSTEMS APPLICABLE TO SURRY INDUSTRY DATA CONSERVATIVELY EXTRAPOLATED TO DETERMINE FREQUENCY OF WATER HAMMER SEVERE ENOUGH TO CAUSE COMPONENT FAILURE FLOOD HAZARD DEVELOPED BASED ON LOG LINEAR CORRELATION AND KNOWLEDGE OF MAXIMUM BREAK SIZES DOMINANT CONTRIBUTORS WERE MEDIUM SIZE BREAKS IN* Pl.PE, VALVE, OR EXPANSION JOINT

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INTERNAL FLOODING REANAL VSIS METHODOLOGY FOR THE TURBINE BUILDING

CORROSION, FATIGUE, MANUFACTURER DEFECTS)

MAINTENANCE ACTIVITIES INADVERTENT STOP LOG REMOVAL

- - WATERBOX MAINTENANCE

SUMMARY

OF SIGNIFICANT DIFFERENCES BETWEEN ORIGINAL INTERNAL FLOODING ANALYSIS AND REANALYSIS.

FOR THE TURBINE BUILD-ING SIGNIFICANT FACTOR.

. OVERPRESSURE TRANSIENT FREQUENCY OF WATER HAMMER.

FREQUENCY OF RUPTURE CONDITIONAL PROBABILITY OF RUPTURE ORIGINAL ANALYSIS ASSUMED -400 PSI PEAK PRESSURE REANALYSIS CALCULATED PEAK PRESSURE FOR SW

& CW 96",42", AND 36" PIPE AND COMPONENTS ONLY EVENTS CAUSING

- ALL EVENTS w*1TH VALVE WATER HAMMER SEVERE DISC SEPARATION FROM

  • ENOUGH TO CREATE OPERATOR FLOOD EVENT FREQUENCY OF WATER HAMMER

-1 FREQUENCY OF WATER HAMMER TIMES PROBABILITY OF RUPTURE BASED ON INDUCED STRESS PER NUREG/

CR-5102 RESIDUAL INTERNAL MECHANISMS. NEGLIGIBLE I

QUANTIFIED/INCLUDED MAINTENANCE ERRORS HEAVY LOADS FIRE NEGLIGIBLE NEGLIGIBLE NEGLIGIBLE QUANTIFIED/INCLUDED QUALITATIVELY ASSESSED QUALITATIVELY ASSESSED

ESTIMATE OF CONSERVATISM IN ORIGINAL ANALYSIS FOR TURBINE BUILDING FLOODING A. BASE CASE AS OF 8/30/91 B. STATUS AS OF 10/31/91 C. CURRENT STATUS AS OF 11/22/91 GOVERNING ASSUMPTIONS

1. FREQ OF WATER HAMMER DOES NOT ACCOUNT FOR SURRY SPECIFIC FACTORS
2. 2 OF 9 SUMP PUMPS
1. FREQ OF WATER HAMMER ACCOUNTS FOR SURRY SPECIFIC FACTORS
2. CRITICAL EXPANSION JOINTS RECENTLY REPLACED
3. 7 OF 9 SUMP PUMPS
1. FREQ OF WATER HAMMER ACCOUNTS FOR SURRY SPECIFIC FACTORS.
2. CRITICAL EXPANSION JOINTS RECENTLY REPLACED
3. 7 OF 9 SUMP PUMPS 4.. SW EXPANSION JOINT SHIELDS WHICH ARE NOW INSTALLED ORiGINAL ANA~YSIS CDF(PER YB>

1.0IE-3 1.0E-4 4.0E-5 BASE CASE. CONSERVATISM= ONE ORDER OF MAGNITUDE REANALYSIS CDF (PER YB>

1.2E-4 3.0E-5 *

  • 2.1E-5 e

COMPARISON OF OVERALL INTERNAL FLOODING ANALYSIS RESULTS ORIGINAL ANALYSIS CDF (PER YR)

ORIGINAL CASE (8/30/91) 1.1 E-3 FLOOD HAZARD PREDOMINANTLY WATER HAMMER WATER HAMMER FREQUENCY/PLANT RESPONSE BASED ON GENERIC DATA AND LOG LINEAR MODEL 2 OF 9 SUMP PUMPS CURRENT CASE (11/22/91) 9.9E-5

.BACKFLOW PREVENTION DEVICES 7 OF 9 SUMP PUMPS FLOOD HAZARD BASED ON CALCULATED PRESSURE INSPECTION PROGRAMS CRITICAL EXPANSION JOINTS RECENTLY REPLACED SHIELDS ON SW MOV EXPANSION JOINTS

. REANALYSIS CDF (PER YR) 2.2E-4 5.1E-5 e

i I

INTERNAL FLOODING REANALYSIS CONCLUSIONS TURBINE BUILDING CONTRIBUTION WAS

  • CONSERVATIVE BY APPROXIMATELY A FACTOR OF TEN USING THE ORIGINAL.ANALYSIS METHODOLOGY OVERALL INTERNAL FLOODING ANALYSIS WAS CONSERVATIVE BY APPROXIMATELY A FACTOR OF FIVE FOR THE ORIGINAL ANALYSIS..

CURRENT OVERALL CDF FOR SURRY SHOWS THAT THE VULNERABILITY DUE TO FLOODING HAS BEEN SIGNIFICANTLY REDUCED

ASSESSMENT OF OTHER FLOOD INITIATOR'S

  • VIRGINIA POWER M. L. BOWLING MANAGER -NUCLEAR -LICENSING & PROGRAMS

REVIEW OF OTHER FLOOD INITIATORS PURPOSE WAS TO QUALITATIVELY ADDRESS THE POTENTIAL TO CREATE FLOODING FROM OTHER INITIATING EVENTS NO SIGNIFICANT FLOOD INITIATORS WERE IDENTIFIED RESPONSE TO G. L. 88-20 SUPP. 4 (IPEEE), DUE BY.JUNE 1994, WILL QUANTITATIVELY ADDRESS THE FOLLOWING ASPECTS

'SEISMIC EV.ENTS INTERNAL FIRES HIGH WINDS AND TORNADOES

-

  • EXTERNAL FLOODS TRANSPORTATION AND NEARBY FACILITY ACCIDENTS

QUALITATIVE REVIEW OF OTHER FLOOD INITIATORS -

SERVICE WATER & CIRCULATING WATER SYSTEMS

  • . SEISMIC ASSESSMENT.

CW INLET PIPING AND ISOLATION MOVs ARE DESIGNED TO SEISMIC CLASS I CRITERIA

. SW INLET PIPING AND ISOLATION MOVs ARE DESIGNED TO SEISMIC CLASS I CRITERIA

!EMERGENCY POWER SUPPLIES FOR CW AND SW MOVs CONDENSER WELL SUPPORTE-D AND WILL MAINTAIN STRUCTURAL INTEGRITY FOLLOWING DBE TURBINE BUILDING STRUCTURAL FRAME WILL NOT COLLAPSE AND, TH-EREFORE, WILL NOT DAMAGE e

SAFETY RELATED EQUIPMENT EXISTING SCAFFOLDING HAS BEEN ASSESSED FOR

.POTENTIAL INTERACTION WITH COMPONENTS THAT COULD INITIATE FLOODING.* FUTURE SCAFFOLDING WILL LIKEWISE BE REVIEWED

QUALITATIVE REVIEW OF OTHER FLOOD INITIATORS-SERVICE WATER & Cl,RCULATING WATER SYSTEMS continued FIRE POTENTIAL TO CREATE A FLOODING EVENT*IN THE TURBINE

  • BUILDING IS VERY LOW BECAUSE'OF MITIGATION AND PREVENTION MEASURES.

AREA SPRINKLERS, DELUGE SYSTEMS, AND CO2 SYSTEMS FLOW SHIELDS AROUND EXPANSION JOINTS ALSO SERVE TO SHIELD DEVICES FROM FIRE SOURCES FIRE WATCH REQUIRED FOR HOT WORK, SUCH AS CUTIING OR WELDING TRAINED FIRE BRIGADE ONSITE STATION PROCEDURES CONTROL THE AMOUNT OF COMBUSTIBLES PERMITTED IN THE AREA OIL SYSTEMS SURROUNDED BY CONTAINMENT DIKES

QUALITATIVE REVIEW OF OTHER FLOOD INITIATORS-SERVICE WATER & CIRCULATING WATER SYSTEMS continued*

VEHICLE DAMAGE

-. VAL VE PITS ARE NOT DIRECTLY ACCESSIBLE TO VEHICLE TRAFFIC PATTERNS

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MOTORIZED VEHICLES ARE NOT ROUTINEL V USED IN TURBINE BUILDING BASEMENT WHICH IS THE AREA CONTAINING THE MOST IMPORTANT FLOOD INITIATING COMPONENTS HEAVY LOADS

  • PROTECTION FOR LOADS CARRIED BY TURBINE BUILDING CRANE PROVIDED BY NINE INCH CONCRETE

.TURBINE DECK WHICH COVERS THE INTERIOR OF MOST OF THE TURBINE BUILDING EVALUATION WILL BE PERFORMED USING NUREG-061.2 AS A GUIDELINE e

QUALITATIVE REVIEW OF OTHER FLOOD INITIATORS-SERVICE WATER & CIRCULATING WATER SYSTEMS continued TORNADO TURBINE BUILDING SUPERSTRUCTURE DESIGNED TO WITHSTAND DESIGN BASIS TORNADO GENERATED LOADS CW AND SW VALVES AND PIPING LOCATED BELOW GROUND ADJACENT STRUCTURES WOULD SHIELD THREE SIDES OF THE

. MAINTE.NANCE INDUCED FLOODS BOTH HIGH FREQUENCY AND HIGH CONSEQUENCE MAINTENANCE INDUCED FLOODS WERE CON~IDERED IN THE REANALYSIS CURRENT PLANT FLOOD CONTROL MEASURES PROCEDURALIZED TAGOUT CONTROLS TO INCLUDE INDEPENDENT VERIFICATION DOUBLE ISOLATION OR OTHER COMPENSATORY MEASURES UTILIZED e

REVIEW OF COMPLETED ACTIVITIES, FUTURE PLANS, AND CONCLUSIONS VIRGINIA POWER

COMPLETED PHYSICAL MODIFICATIONS AND ACTIVITIES

  • . ENHANCED FLOODING RESPONSE/PREVENTION
  • PROCEDURES ABNORMAL ANNUNCIATOR AND RESPONSE PROCEDURES ANNUAL PM PROCEDURES FOR FLOOD PROTECTION DEVICES REFUELING PROCEDURES FOR TESTING FLOOD PROTECTION AND ALARM SYSTEMS INSTALLATION OF CHARGING PUMP CUBICLE DRAIN LINE BACKFLOW PREVENTION DEVICES FLOW SHIELD INSTALLATION ON EXPANSION

- JOINTS IN SERVI.CE WATER SUPPLY LINES FOR BEARING COOLING AND COMPONENT COOLING REPAIR/REPLACEMENT OF CERTAIN BACKFLOW.

PREVENTION DEVICES IN NEED OF REPAIR COMMUNICATION OF IMPORTANCE OF FLOOD PROTECTION PROGRAM TO STATION PERSONNEL

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ONGOING ACTIVITIES

  • IMPROVED SUMP PUMP RELIABILITY-MAINTAIN AT LEAST 7 PUMPS OPERABLE -AS AN INTERIM MEASURE, MAINTAINING 9 PUMPS OPERABLE. '
  • . INSPECTION PROGRAM AND SERVICE LIFE REPLACEMENT PROGRAM FOR EXPANSION. JOINTS INSPECTION PROGRAM FOR VALVES (BOLTING AND CONNECTING PINS) AND SW PIPING FOUR STANDBY DIESEL DRIVEN SUMP PUMPS STOP LOG STAGING, PROCEDURES, AND ASSIGNED PERSONNEL AND EQUIPMENT

,e

FUTURE PLANS RELOCATION OF POWER SOURCE FOR EXISTIN'G TURBINE BUILDING SUMP PUMPS ASSESSMENT OF SUBMERSIBLE OPERATORS FOR

, BC/CC MOVs.

EXPANS.ION JOINT FLOW SHIELDS INSPECTION AND MAINTENANCE (INCLUDING REPAIRS, AS REQUIRED)

REPLACEMENT OF EXPANSION JOINTS NOT PREVIOUSL V REPLACED

  • .PROCEDURE REVISIONS*FOR ISOLATION OF CW AND SW PIPING FOR MAINTENANCE DURING OUTAGES

. FUTURE PLANS.

continued*

ASSESS THE NEED FOR A FLOOD MITIGATION EQUIPMENT RELIABILITY.

PROGRAM PROCEDURES VALIDATION OF OPERATOR ACTIONS FOR FLOOD MITIGATION

..

  • A REASSESSMENT OF CW/SW PIPING INSPECTION

.SCHEDULES.

INDEPENDENT REVIEW OF LICENSING DESIGN BASIS

CONCLUSIONS CURRENT CDF DUE TO INTERNAL FLOODING IS 9.9E-5 PER.

REACTOR VEAR*

CURRENT CDF IS CONSERVATIVE BY APPROXIMATELY A FACTOR OF TWO (5.1 E-5)

  • . CURRENT OVERALL CDF FOR SURRY SHOWS THAT THE VULNERABILITY DUE TO FLOODING HAS BEEN SIGNIF!CANTL V REDUCED OTHER EVENTS ARE NOT SIGNIFICANT FLOOD INITIATORS
  • ADDITIONAL ACTIONS PLANNED OR BEING EVALUATED WILL FURTHER REDUCE THE LIKELIHOOD AND/OR CONSEQUENCES OF INTERNAL FLOODING

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