ML20154G776

Summarizes 880429 Enforcement Conference Re Degradation of Nuclear Svc Water Sys & Auxiliary Feedwater Sys Due to Clam Infestation.List of Attendees & Handout Encl

ML20154G776
Person / Time
Site:	Catawba
Issue date:	05/13/1988
From:	Grace J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
To:	Tucker H DUKE POWER CO.
References
NUDOCS 8805250086
Download: ML20154G776 (49)

Text

_ _ - _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ -

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May 13, 1988 Docket Nos. 50-413, 50-414 License Nos. NPF-35, NPF-52 Duke Power Company ATTN: Mr. H. B. Tucker, Vice President Nuclear Production Department 422 South Church Street Charlotte, NC 28242 Gentlemen:

SUBJECT:

ENFORCEMENT CONFERENCE

SUMMARY

(NRC INSPECTION REPORT N0S, 50-413/88-14 AND 50-414/88-14)

This letter refers to the Enforcement Conference held at our request on April 29, 1988.

This meeting concerned activities authorized for your Catawba the Nuclear Service Water (RN) system and Auxiliary Feedwater (CA) gradation of facility. The issue discussed at this conference related to the de system due to clam infestation.

A summary, a list of attendees, and a copy of your handout are enclosed.

We are continuing our review of these issues to determine the appropriate enforcement action.

In accordance with Section 2.790 of the NRC's "Rules of Practice," Part 2, Titir, 10, Code of Federal Regulations, a copy of this letter and its enclosures will be placed in the NRC Public Document Room.

Should you have any questions concerning this matter, please contact us.

Sincerely, Original Signed by J. Nelson Grace J. Nelson Grace Regional Administrator

Enclosures:

1.

Enforcement Conference Summary 2.

List of Attendees

-3.

Handout cc w/encis:

T. B. Owen, Station Manager Senior Resident inspector - McGuire bec w/encis:

(See page 2)

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8805250086 880513 PDR ADOCK 05000413 i

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May 13, 1988 i

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K. N. Jabbour, NRR NRC Resident Inspector DRS, Technical Assistant Document Control Desk State of South Carolina l

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, l 'O s May 13, 1988 3.

y ENCLOSURE 1 ENF0RCEMENT CONFERENCE

SUMMARY

0n April 29, 1988, representatives of Duke Power Company (DPC) met with the NRC in the Regior II office in Atlanta, Georgia to discuss degradation of the Nuclear Service Water (RN) and Auxiliary Feedwater (CA) systems due'to clam infestation at Catawba Unit 2.

The event resulting in the degradation occurred on March 9, 1988, and was investigated by an Augmented Inspection Team (AIT).

Following opening remarks given by M. L. Ernst, NRC, RII Deputy Regional Administrator, DD6 cave a presentation (see Enclosure 3) which addressed NRC conce 's.

The presentation covered a sequence and analysis of the events, a design evaluation Jf the transient and transient trit results, the safety signift:ince, past programs for clam control, and Catawba clam task force activities.

M. McIntosh, DPC, Manager Nuclear Station closed the DPC presentation by statir g that DPC felt tneir actions.were prudent and based on the information available; that DPC had aggressively pursued the probica immediately after the event and their short-term corrective acti'ns had been effective; and that the-AIT was constlJctive cnd beneficial to the short-term solutions.

The h1C is presently considering enforcement action on these issues.

This me.r*1ng served to enhance Region II's understanding of the issues and DPC's corrective actions.

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May 13, 1988 ENCLOSURE 2 LIST OF ATTENDEES U. S. Nuclear Regulatory Commission M. L. Ernst, Deputy Regional Administrator L. A. Reyes, Director, Division of Reactor Projects (DRP)

E. W. Merschoff, Deputy Director, Division of Reactor Safety (DRS)

4. L. Brownlee, Branch Chief, DRP T. A. Peebles, Section Chief, DRP P. K. VanDoorn, Senior Resident Inspector - Catcwba, DRP K. N. Jabbour, Catawba Project Manager, NRR B. R. Bonser, Project Engineer, DRP J. W. Thompson, Reactor Engineer, NRR.

M. S. Lesser, Residtent Inspector - Catawba, DRP B. Uryc, Senior Enforcement Coordinator, Enforcement and Investigation Coordination Staff (EICS)

W. J. Ross, Reactor Inspector, Division of Radiation Safety and Safeguards-(DRSS)

R. J. Goddard, Regional Counsel R. D. Starkey, Reactor Inspector, DRS R. P. Schin, Reactor Inspector, DRS L. M. Slack, EICS, Assistant B. R. Crowley, Reactor Inspector, DRS G. R. Jenkins, Director, EICS K. I. Parezewski, Reactor Engineer, NRR Duke Power Company M. D. McIntosh, Manager Nuclear Station T. B. Owen, Manager Catawba Nuclear Station N. A. Rutherford, Manager Licensing C. L. Hartzell, Compliance Engineer-Catawia P. G. LeRoy, Licensing Engineer W. A. Heller, Manager Technical Services D. Tower, Shift Operating Engineer E. W. Fritz, Design Engineer J. A. Karner, Test Engineer J. E. Col Jr., Technical Systems Manager J. C. Knight, Supervising Scientist G. B._ Swindlehurst, Supervising Design Engineer dI

m ENCLOSURE 3

.o OPENING REMARKS CATAWBA NUCLEAR STATION'S FIRST PRIORITY WAS NUCLEAR SAFETY.

THIS WAS DEMONSTRATED BY THE FACT THAT UNIT 1 WAS REMOVED FROM SERVICE WHEN THE PROBLEM WAS DETERMINED TO BE GENERIC.

THE ROOT CAUSE OF THE CA SYSTEM RESPONSE WAS THOROUGHLY REVIEWED AND UNDERSTOOD PRIOR TO RESTART.

THE DESIGN Basis FOR THE OPERATION OF THE CA SYSTEM WAS REVIEWED AND DEMONSTRATED SOUND DURING TRANSIENT TESTING.

THE OPERABILITY OF THE CA SYSTEM UNDER DEGRADED FLOW WAS THOROUGHLY ANALYZED.

THE COMMITMENTS FOR INSPECTION AND TESTING OF-CATAWBA NUCLEAR STATION IN RESPONSE TO IE BULLETIN 81-03 WERE FOLLOWED.

PROGRAMS ASSOCIATED WITH THESE COMMITMENTS NEED STRENGTHENINJ.

SHORT TERM ACTION TO INSURE PIPING IS FREE OF CLAMS HAS ALREADY BEEN TAKEN.

LONG TERM PLANS ARE UNDER REVIEW,

s 4

i S:EQU:EXC:E OF

EV U TS oAUXI

A R Y F E E J W A T ; E R S Y S '; H D E S

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i oVARCH 9

SEQUENCE 0: 7

IVENTS a

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CATAWBA NUCLEAR STATION SYSTEM ABBREVIATIONS ABBREVIATION SYSTEM DESCRIPTION CA AUXILIARY FEEDWATER CS CONDENSATE STORAGE KC COMPONENT COOLING KF SPENT FUEL P0OL COOLING NS CONTAINMENT SPRAY NW CONTAINMENT VALVE INJECTION WATER RC CONDENSER COOLING WATER RF FIRE PROTECTION RL LOW PRESSURE SERVICE WATER RN NUCLEAR SERVIVE WATER l

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i CATAWBA NUCLEAR STATION AUXILIARY FEEDWATER SYSTEM CA SYSTEM SUCTION SOURCES:

e AUXILIARY FEEDWATER CONDENSATE STORAGE TANK (CACST) eUPPER SURGE TANK (UST) eCONDENSER HOTWELL eNUCLEAR SERVICE WATER SYSTEM (RN) e CONDENSER CIRCULATING WATER SYSTEM (RC).

MOTOR DRIVEN CA PUMP AUTO-STARTS:

e 1/4 STEAM GENERATORS AT LO-LO LEVEL e LOSS OF BOTH FEEDWATER PUMPS eS I

ECTION M NE DRIVEN CA PUMP AUTO-STARTS:

e 2/4 STEAM GENERATORS AT LO-LO. LEVEL e BLACKOUT.

MOTOR DRIVEN PUMPS LOW SUCTION PRESSURE PROTECTION!

AUTO-SWAP TO RN:

EUMP TRIP!

l e 2/3 SUCTION PRESSURE o 2/3 SUCTION PRESSURE l

SWITCHES INDICATE LOW FOR 3 SWITCHES LOW FCR 3 TO 5 i

TO 5 SECONDS SECONDS l

e PUMP BREAKER IS CLOSED e PUMP BREAKER IS CLOSED j

e AUTO-START SIGNAL IS e No AUTO-START SIGNAL l

8 PRESENT.

PRESENT.

TURBINE DRIVEN PUMP LOW SUCTION PRESSURE PROTECTION:

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AUTO-SWAP To RN:

PUMP TRIP:

e 2/3 SUCTION PRESSURE e 2/3 SUCTION PRESSURE SWITCHES LOW FOR 3

,'O 5 SWITCHES LOW FOR 3 TO 5 SECONDS SECONDS e SA 2 OR SA 5 ARE e SA 2 OR SA 5 ARE "NOT CLOSED" "NOT CLOSED" e TRIP AND THROTTLE VALVE e TRIP AND THROTTLE VALVE l

OPEN OPEN e AUTO-START SIGNAL IS e NO AUT0-START SIGNAL IS PRESENT.

PRESENT, l

^

c CATAWBA NUCLEAR STATION AUXILIARY FEEDWATER AUT0-SWAP TO ASSURED SOURCE l

l SEQUENCE OF EVENTS MARCH 9, 1988 TIME MIN:SEC EVENT DESCRIPTION S/G HI-HI LEVEL (P-14)

SIGNAL TURBINE TRIP MAIN FEEDWATER PUMP TRIP 0

CA MOTOR DRIVEN PUMPS AUT0-START ON LOSS OF MAIN FEED PUMPS 3

L0 CA SUCTION PRESSURE INDICATION ON OPERATOR AfD COMPUTER (0AC) 7 RN-CA AUTO-SWAP INITIATED 7

CA 15A INDICATES "NOT CLOSED" l

7 RN 250A INDICATES "NOT CLOSED" 12 CA 15A INDICATES "0 PEN" 21 RN 250A INDICATES "0 PEN" 28 2/4 S/G LO-L0 SIGNAL 32 SA 2 INDICATES "NOT CLOSED" 35 SA 5 INDICATES "NOT CLOSED" 54 L0 CA SUCTION PRESSURE INDICATION CLEARS ON 0AC 1:53 SA 2 INDICATES CLOSED 13:09 RN 250A INDICATES "NOT OPEN" 13:18 RN 250A INDICATES "CLOSED" l

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ANALYSIS OF IVEXT o:~YYIJ:ATI POST TRIP ANAiYSIS o'30 ST TR : ~3 IXVESTIGATION

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oCONCLUSIONS

n POST TRIP ANALYSIS

• OPERATOR INTERVIEWS REVEALED LOW CA FLOWS

• OPERATOR INTERVIEWS REVEALED CA "A" TRAIN SWAP TO RN

• TRANSIENT MONITOR DATA INDICATED DEGRADED FLOW TO STEAM GENERATORS A AND B e POST-TRIP CA FLOW VERIFICATION YlELDED THE FOLLOWING RESULTS:

FLOW VERIFICATION ALIGNMENT STEAM STANDBY ALIGNED GENERATOR READINESS INDIVIDUALLY S/G A 220 GPM 320 GPM S/G B 100 GPM 190 GPM S/G C 310 GPM N/A S/G D 310 GPM N/A l

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GPM CATAW8A 2 TRANSIENT at 18: 25: 37 on 3-9-88 GPM 700.000 i i i i

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9 TRIP MAX MIN PID MESSAGE

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~~ 4.12500 311.250 3.75000 A0977 CA Fu.UW TO S/G D 154.125 617.625 3.75000 A0976 CA FLOW TO S/G C

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.375000 617.625.375000 A0975 CA "LON TO S/G B

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18G.065 319.o56 78.1632 A1035 CF FLOW TO S 'G A C A fl07.ZLE Initiating point was D2720 CF PUMP TURB A

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~30ST TR.: P I NV;EST.: G AT.: 0N oCA 0:3E RA3IL :TY INVEST: GAT:0N RN ASSLRED SOLRCE VER: 4' CAT.ON o ACTO SWAP INV;ESTIGAT.:0N T R.-.A,N,.., I _.N r.i 1i<

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r-CA SYSTEM CLEANUP AND OPERABILITY VERIFICATION SYSTEM CLEANUP:

RESULTS:

• CA LINES TO STEAM GENERATORS e "B" FLOW CONTROL VALVE FLUSHED ALMOST CLEAN "A" FLOW CONTROL FOULED WITH CLAMS, REFLUSHED AND REINSPECTED BOTH VALVES CLEAN, e INSPECTED FLOW CONTROL e BOTH FLOW CONTROL VALVES VALVES FROM CAPT TO S/G'S B

CLEAN, AND C e INSPECTED CAPT LUBE OIL e PRESSURE REDUCTION ORIFICE COOLER LINE PRESSURE

CLEAN, REDUCTION ORIFICE e INSPECTED AND REPLACED CA e MINIFLOW FLOW VALVE WAS PUMP 2A MINIFLOW VALVE

.FOUND TO HAVE A "GUMMY" SUBSTANCE ON IT WHICH RESTRICTED FREE TRAVEL, l

OPERABILITY VERIFICATIONS:

RESULTS:

o CA PUMP 2A HEAD CURVE e NO APPARENT DEGRADATION.

VERIFIED e FLOW BALANCED CA LINES T0 e ALL LINES SUCCESSFULLY FLOW l

STEAM GENERATORS A, B AND C BALANCED.

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• SETUP AND STROKE TIMED ALL e ALL VALVES SUCCESSFULLY I

VALVES DISASSEMBLED.

SETUP AND RETIMED, l

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r RN ASSURED SOURCE OPERABILITY VERIFICATION SYSTEM:

RESULTS:

• RN TO NW FLOW

• FLOW RATES OBTAINED WERE ACCEPTABLE, VERIFICATION e RN TO KC LINES

• KC 1A, N0 FLUSHING REQUIRED, RADIOGRAPHED THEN FLUSHED AS e KC IB, THE LINE WAS FLUSHED AND REQUIRED RERADIOGRAPHED e KC 2A, THE LINE WAS FLUSHED AND RERADIOGRAPHED e KC 2B, THE LINE WAS FLUSHED AND RERADIOGRAPHED TWICE

• RN TO KF LINES

• KF 1A, THE LINE WAS FLUSHED AND RADIOGRAPHED THEN RERADIOGRAPHED.

FLUSHED AS

s M 4%,

REQUIRED e KF IB, N6 u.m:r vaatnycu, cfNE FLUSHED AND RERADIOGRAPHED,

• KF 2A, NO CLAMS OBSERVED, LINE FLUSHED AND RERADIOGRAPHED,

• KF 2B, THE LINE WAS FLUSHED AND RERADIOGRAPHED,

• RN TO CA LINES e BOR0 SCOPIC EXAMINATION OF THE RN/CA FLUSHED SUCTION PIPING REVEALED NO CLAMS REMAINING.

SPOT RADIOGRAPHS OF UNIT 2 RN SUPPLY PIPING TO CA REVEALED NO

CLAMS,

M h

G s

DESIGN EVALUATION OF TRANSIENT I DESIGN BASIS OF RN-CA SWITCHOVER LOGIC 8 INVESTIGATION OF LOW SUCTION HEADER PRESSURE CONDITIONS 0 TRANSIENT TEST RESULTS i

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DESIGN BASIS OF RN-CA SWITCH 0VER LOGIC O SAFETY FUNCTION - ENSURE ADEQUATE SOURCE OF EMERGENCY FEEDWATER IN THE EVENT OF FAILURE OF NORMAL CONDENSATE SOURCES.

CRITICAL PARAMETER - ACCOMPLISH SWITCHOVER To RN WITHOUT VIOLATING CA PUMP NPSH REQUIREMENTS.

O OPERATIONAL CONSIDERATION - PROVIDE ADEQUATE OPERATING MARGIN TO PRECLUDE INADVERTENT SWITCHOVER TO RN.

CRITICAL PARAMETER - ALLOW FOR PUMP START TRANSIENT WITHOUT CAUSING SWITCHOVER TO RN.

IIME DELAY CIRCUIT ON PUMP START LOGIC.

f.

4 INVESTIGATION OF LOW SUCTION HEADER PRESSURE CONDITIONS O INSTRUMEWTATION/ CIRCUITRY VERIFICATIONS PRESSURE SWITCH CALIBRATIONS VERIFIED TIME DELAYS VERIFIED INSTRUMENT IMPULSE LINES VERIFIED OPERABLE WIRING TO 0AC VERIFIED RN-CA SWITCH 0VER LOGIC VERIFIED SUCTION PRESSURE SWITCH OUTPUT RELAY CONTACTS VERIFIED 0

0 INSPECTION OF SUCTION HEADER VALVES 2 CA 129 2 CA 3 2 CA 1 2 CS 19 i

l 8 MEASURE ACTUAL CONDITIONS IN SUCTION HEADER (TRANSIENT TEST)

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TRANSIENT TEST RESULTS LA$f CALCULATED PRESSURE fSbDfhkkfh CAMDP'S ONLY 13-21 PSIG 17.6 PSIG CACST ISOLATED CAMDP's ONLY 25-38 PSIG 30.2 PSIG CACST OPEN CAMDP's & TDP 17-29 PSIG 21 PSIG CACST OPEN CAMDP's a TDP 2-7 PSIG 4.1 PSIG CACST ISOLATED UST 60 - 80% FULL CACST 80 - 100% FULL

1 CATAVBA NUCLEAR STATION TRANSIENT TEST RESULTS UST

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CA6 CLOSED So 45 l

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TIME - SECONDS 7

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CATAVBA NUCLEAR STATION TRANSIENT TEST RESULTS UST

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TIME - SECGNOS l

CONCLUSIONS oCA SYSTEM OPERABLE AFTER FLUSHING 3ASED ON FLOW BALANCE RESULTS i

o CA SYSTEM NOT DEGRADEJ FROM CLAM

'ASSAGE BASED ON PUMP HEAD CURVE 1

o RN ASSURED SOURCES VERIFIED OPERABLE

)

o"A" TRA X

AUTO SWAP OCCURED DUE TO CACST BEING ISOLATED AND SHORT TIME DELAY SETTING I

1 CORRECTIVE ACTIONS i

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oMAINTAIN CACST ALIGNED TO CA PUMP SUCTION i

OR MAINTAIN UST LEVEL GREATER THAN 907.

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oINCREASED TIME DEL /V SETTING "A"

TRAIN TIMER i

oREPEATED RN TO CA SWAPOVER TEST.

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oREPEAT TRANSIENT TEST l

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SAFETY ANALYSIS CONSEQUENCES ANALYSIS OF THE IMPACT OF A DEGRADED AUXILIARY FEEDWATER SYSTEM ON THE LIMITING FSAR TRANSIENT e

BACKGROUND e

TRANSIENT SCENARIO AND ANALYSIS METHODOLOGY e

SIMULATION RESULTS C0ljCLUSIONS_

e

l BACKGROUND e FSAR STATES THAT AT LEAST TWO STEAM GENERATORS CAN BE SUPPLIED WITH A MINIMUM 0F 491 GPM OF AUX FEEDWATER e MINIMUM FLOW WITH A NORMAL ALIGNMENT IS 499 GPM AT 1210 PSIG, BASED ON ONE MOTOR-DRIVEN PUMP SUPPLYING TWO SfEAM GENERATORS e DUE TO CLAM. FOULING, THE IMMEDIATELY AVAILABLE AUX FEEDWATER FLOW IS:

STEAM GENERATOR A = 220 GPM STEAM GENERATOR B = 100 GPM NOTE: THE TURBINE-DRIVEN PUMP IS ASSUMED TO FAIL, AND THE B MOTOR-DRIVEN P, UMP SUPPLIES THE FAULTED D STEAM GENERATOR e AT 30 MINUTES C.REDIT IS TAKEN FOR THE OPERATOR MANUALLY REALIGNING THE B MOTOR-DRIVEN PUMP TO STEAM GENERATOR C.

A MINIMUM DEGRADED FLOW 0F 190 GPM IS ASSUMED.

e THE AVAILABLE AUXILIARY FEEDWATER FLOWRATE IS LESS THAN THAT ASSUMED IN THE FSAR CHAPTER 15 TRANSIENT AND ACCIDENT ANALYSES e THE SAFETY CONCERNS TO BE AVOIDED ARE:

- BULK B0llliG IN THE RCS

- RCS OVERPRESSURIZATION

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TRANSIENT SCENARIO AND ANALYSIS METHODOLOGY e THE LIMITING TRAliSIENT IS THE MAIN FEEDWATER LINE BREAK

- BREAK IN D FEEDWATER LINE AT TIME ZERO

- ALL MAIN FEEDWATER FLOW LOST OUT BREAK

- DEGRADED AUXILIARY FEEDWATER FLOW DUE TO CLAM FOULING

- MAXIMUM DECAY HEAT

- OPERATOR ACTION TO MANUALLY REALIGN AUXILIARY FEEDWATER TO STEAM GENERATOR C AT 30 MINUTES e PLANT SPECIFIC SIMULATION OF CATAWBA UNIT 1 USING A THREE-LOOP RETRAN-02 MODEL

-e THE ANALYSIS APPROACH CONSISTS OF A REALISTIC SIMULATION WITH REALISTIC.AND CONSERVATIVE ASSUMPTIONS e

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RESULTS t

SEQUENCE OF EVENTS TIME (SEc)

EVENT 0

FEEDWATER LINE BREAK AT SG D 2.7 PRESSURIZER SPRAY ON 14.5 RX TRIP ON LOW-LOW SG LEVEL 14.8 TURBINE TRIP 19.5 MOTOR-DRIVEN AUX FDW PUMP A STARTS 63 SG D BOILS DRY 171 SAFETY INJECTION ON LOW PZR PRESSURE 181 SAFETY INJECTION PUMPS DELIVERING 300 MINIMUM RCS PRESSURE = 1816 PSIG 393 STEAM LINE ISOLATION a 725 esto 390 MINIMUM PZR LEVEL = 7.7%

420 MINIMUM RCS T-AVE = 520 F 1100 SG PORVs BEGIN CYCLING 1430 PZRISWAJERSOLID 1435 PZR PORVs BEGIN CYCLING 1800 MOTOR-DRIVEN AUX FDW PUMP B ALIGNED TO SG C 2400 END OF SIMULATION

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W CONCLUSIONS e

THE RCS T-AVE NEVER EXCEEDS 570 F POST-TRIP, WHICH IS THE NORMAL POST-TRIP TEMPERATURE FOLLOWlHG ANY TRANSIENT THAT RESULTS IN A MAIN STEAM ISOLATION SIGNAL e

THE INITIALLY AVAILABLE AUXILIARY FEEDWATER FLOW IS 320 ces (a 1000 esic).

WITH OPERATOR ACTION TO REALIGN MOTOR-DRIVEN AUX FDW PUMP B AT 30 MINUTES, THE AVAILABLE TOTAL FLOW IS 510 GPM (a 1000 PSIG).

AT THE MhXIMUM SG PRESSURE THAT RESULTS DURING THE TRANSIENT, THE TOTAL AVAILABLE FLOW IS 452 seM.

e THE AUX FEEDWATER FLOW REQUIRED TO REMOVE DECAY HEAT AND REACTOR COOLANT PUMP HEAT AT 40 MINUTES IS 443 GPM e

AT 40 MINUTES THE AVAllABLE HEAT SINK EXCEEDS THE HEAT LOAD AND THEREFORE THE TRANSIENT HAS SEEN SUCCESSFULLY MITIGATED e

RESTORING A NORMAL POST-TRIP CONDITION WOULD BE ACHIEVED BY

- TERMINATING SAFETY INJECTION

- ESTABLISHING A PRESSURIZER BUBBLE

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- RESTORING STEAM DUMP TO CONDENSER

- RESTORING NORMAL STEAM GENERATOR LEVELS USING MAIN OR AUXILIARY FEEDWATER

x CONCLUSI0i1S (CONT.)

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e THE TRANSIENT RESPONSE OF THE UNIT FOR THE LIMITING FSAR CHAPTER 15 TRANSIENT WITH DEGRADED AUXILIARY FEEDWATER FLOW DUE TO CLAM FOULING DOES NOT RESULT IN ANY UNACCEPTABLE CONSEQUENCES f

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J e

L PAST PROGRAMS.FOR CLAM CONTROL

RESPONSE

TO I.E BULLETIN 81-03 1

oCLAM EXPERIENCE AT CATAWBA RAW WATER MONITORING PROGRAM oCONCLUSIONS

{

9

j RESPONSE TO IE BULLETIN 91-03 i

JULY 8.

1981 PERFORMANCE MONITORING FROGRAM i

l INSPECTION.: D'.!E !: 3 E..:T O E MA INTENANCE 1

r MARC!! I '.~.

1983 DIFFERENTIAL PRESSURE MONITORING l

aNS HEAT EXCHANGER l

aASPSU CHILLER CONDENSER INSPECTIONS DURING ROUTINE MAINTENANCE SEFTEMPER IS.

I983 DIFFERENTIAL PRESSURE MONITORING aKC HEAT EXCHANGER aD/G AIR COMPRESSOR AFTERC00LER INSPECTIONS DURING ROUTINE NAINTENANCE i

OCTOPER 17.

1983 INTERNAL MEMO RECOMMENDING PERIODIC l

FLUSHING OF SNSNP SYSTEM e

l CLAM EXPERIENCE AT CATAWBA PRE 1982 LOW PRESSURE SERVICE WATER SYSTEM e MOTOR COOLER LINES

• RADWASTE AREA "Y" STRAINER

• SUPPLY PIPING TO PLANT FIRE PROTECTION SYSTEM e CLAM SHELLS FOUND IN A FEW DELUGE N0ZZLES

• CLAM SHELLS FOUND IN STRAINER NUCLEAR SERVICE WATER SYSTEM

• NO CLAMS LOCATED SAMPLING 0F LAKE WYLIE AND NUCLEAR SERVICE WATER POND VERIFY CLAMS PRESENT IN VICINITY OF CATAWBA NUCLEAR STATION 8/82 - 2/83 ROUTINE CHILLER MAINTENANCE REVEALS ONE SLIGHT CASE OF CLAM INFESTATION '

SEPTEMBER 82 FIRE PROTECTION STRAINER BASKET INSPECTION REVEALS NO CLAMS OCTOBER 82 SMALL CLAMS FOUND IN MULSIFYRE N0ZZLES DURING FIRE PROTECTION SYSTEM INSERVICE TESTING 82 TO 87 CLAMS PERIODICALLY FOUND IN LOW PRESSURE SERVICE WATER SYSTEM CLAMS FOUND RARELY IN NUCLEAR SERVICE WATER SYSTEM APRIL 87 RN TO CA SUPPLY LINE RADIOGRAPHED FOR CLAMS IN RESPONSE TO TESTING REVIEW COMMITTEE CONCERNS OCTOBER 8'7 CLAMS FOUND IN NUCLEAR SERVICE WATER PUMP LUBE INJECTION LINES MARCH 88 RN TO CA SUPPLY LINE ON UNIT 1 RADIOGRAPHED FOR CLAMS

4 RAW WATER MONITORING PROGRAM MA:

W DIFFERENTIAL 3 PRESS.URE MONITORING THE F0LLOWING HEAT EXCHANGERS OF THE NUCLEAR SERVICE WATER SYSTEM ARE MONITORED FOR DIFFERENTIAL PRESSURE ON A QUARTERLY BASIS:

• COMPONENT COOLING HEAT EXCHANGER e CONTAINMENT SPRAY HEAT EXCHANGER e AUXILIARY SHUTDOWN PANEL AIR HANDLING UNIT CONDENSERS

• DIESEL GENERATOR COOLING WATER HEAT EXCHANGER e DIESEL GENERATOR AIR COMPRESSOR AFTERC00LERS HEAT EXCHANGER PERFORMANCE MONITORING THE FOLLOWING HEAT EXCHANGERS ARE PERIODICALLY TESTED FOR HEAT TRANSFER CAPABILITIES:

e COMPONENT COOLING HEAT EXCHANGERS e CONTAINMENT SPRAY HEAT EXCHANGERS e DIESEL GENERATOR COOLING WATER HEAT EXCHANGERS NUCLEAR SERVICE WATER SYSTEH FLOW BA XNCINb THE NUCLEAR SERVICE WATER SYSTEM CURRENTLY IS BEING FLOW BALANCED ON A YEARLY FREQUENCY OR AS REQUIRED FOR RETESTS DUE TO STATION MODIFICATIONgORMAINTENANCE.

l

CONCLUSIONS o ALL COMMITMENTS RELATIVE TO IE BULLETIN 81-03 HAVE BEEN MET OR EXCEEDED o BASED ON PAST EXPERIENCE CLAMS HAVE NOT BEEN A SIGNIFICANT PROBLEM'IN THE NUCLEAR SERVICE WATER SYSTEM INTERNAL RECOMMENDATIONS RELATIVE TO PERIODIC o

FLUSHING OF THE

~SNSWP" SYSTEM HAVE BEEN MET OR EXCEEDED

I Catawba Clam Task Force Objectives

1. Provide Recommendations to Prevent Inadvertent Swap Over of Auxiliary Feedwater Supply to Nuclear Service Water

2. Review Near Term Raw Water Controls and Provide Appropriate Recommendations

3. Develop a Long Term Solution to Resolve the Clam Problem at Catawba

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Catawba Clam Task Forc.e Near Term Plan

1. Define Clam Life-cycle and Control Mechanisms

2. Brief Review of Catawba's History /

Problems with Clams

3. Review Industry and Duke Fossil Experience and. Solutions

4. Review Past Responses and Commitments l

to NRC on Clams l

5. Review Catawba's Recent Event in Regard to Clams

6. Review Catawba's Recent Event in Regard to Auxiliary Feedwater, Condensate Storage, and Nuclear Service Water System Interaction

Catawba Clam Task Force Near Term Conclusions

1. The Potential for Clam Larvae to Get into RN Systems at Catawba is High

2. The Potential for Adult Clams to Get into RN Systems at Catawba is Low

3. No Significant Clam Infestation Has Been Experienced in High Flow Areas of Catawba RN Systems

4. Significant Clam Fouling Can Occur in Low Flow and Stagnant Areas ofCatawba's RN Systems

5. Catawba's Present Flushing Velocities are Adequate for Near Term Clam Control

6. The Near Term Problem with Clams Potentially l

Degrading Safety Systems at Catawba is in Low Flow and Stagnant Lines I

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Catawba Clam Task Force Near Term Recommendations

1. Add Analog Point to OAC with 2 Alarms

1. UST < 66 %

Level

2. CA6 Closed & UST < 90%

2. Clam Findings Should Be Better Documented

3. RN to CA Lines - Flush Monthly

- Install Strainer to Collect Clams During Flush l

4. RN to KC Lines - Flush Quarterly RN to KF Lines RN to NW Lines

Results of Latest RN to CA Flush April 8,9, & 10 Procedure - Flush 3 Times for 15 Minutes with a Strainer Flush for 30 Minutes without Strainer Flush for 5 Minutes with a Strainer with Condensate l

l Results

- 1 Live Clam 1/4 inch 341/2 Clam Shells ( 251/2.from 2B Line )

101/2 Shell Pieces l

Conclusion - Lines were Relatively Clean Consider Extending RN to CA Flush Frequency After the Next l

Monthly Flush

O Catawba Clam Task Force Long Term Solution Development

1. Develop Long Term Alternatives to Resolve Problems Found in Near Term Review.

Consider:

a. Design Modifications

b. Chemical Treatment

c. Mechanical Techniques

d. Operational Changes t

2. Provide Cost. Benefit Analysis of Potential Solutions

3. Confirm Optimum Solution by Test and/or Analysis

4. Define Method to Track Effectiveness of Solution

5. Provide Report to Management r--.,-,--

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