ML20058N774

Summary of Operating Reactors Events Meeting 93-45 on 931201

ML20058N774
Person / Time
Site:	Mcguire, Palo Verde, Kewaunee
Issue date:	12/03/1993
From:	Chaffee A Office of Nuclear Reactor Regulation
To:	Grimes B Office of Nuclear Reactor Regulation
References
OREM-93-045, OREM-93-45, NUDOCS 9312220258
Download: ML20058N774 (18)

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December 3, 1993 MEMORANDUM FOR:

Brian K.

Grimes, Director Division of Operating Reactor Support i

FROM:

Alfred E. Chaffee, Chief Events Assessment Branch Division of Operating Reactor Support

SUBJECT:

OPERATING REACTORS EVENTS BRIEFING j

DECEMBER 1, 1993 - BRIEFING 93-45 On December 1, 1993, we conducted an Operating Reactors Events i

Briefing (93-45) to inform senior managers from offices'of the Chairman, ACRS, SECY, OE, NRR, AEOD, and regional offices of.

selected events that occurred since our last briefing on.

November 24, 1993. lists the attendees.

presents the significant elements of the discussed events.

contains reactor scram statistics for the week ending November 28, 1993.

No significant events were identified for input into the NRC Performance Indicator Program.

original signed by Alfred E.

Chaffee, Chief i

Events Assessment Branch

,1-Division of Operating React >r Support

Enclosures:

As stated DISTRIBt ION:

g; Central _ Files cc w/ enclosures:

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OFFICIAL RECORD COPY

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DOCUMENT NAME:

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v 9312220258 931203J O3 170.,u,? 0 eDn one unnB PDR[

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T.'Murley, NRR '(12G18)

R. Laufer (PDIII-3).

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'F. Miraglia, NRR (12G18)

J. Hannon (PDIII-3) l

.F. Gillespie, NRR (12G18)

V. Nerses-(PDII-3)

J.' Callan, NRR (12G18)

L. Plisco (PDII-3)

S. - Varga,.- NRR ' (14 E4 )

B. Holian (PDV)

J. Calvo, NRR~ (14A4)

T. Quay (PDV)-

i G. Lainas, NRR (14H3)

J. Roe, NRR-(13E4)-

J. Zwolinski, NRR (13H24) l E. Adensam, NRR (13E4) l

'W. Russell, NRR (12G18)

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J. Wiggins, NRR (7D26)

A. Thadani, NRR (8E2) j S. Rosenberg, NRR (10E4) 1 C. Rossi, NRR (9A2)

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B..Boger, NRR (10H3).

.F. Congel, NRR (10E2)

D. Crutchfield, NRR (11H21) l W. Travers, NRR (11B19)-

D. Coe, ACRS (P-315)

E. Jordan, AEOD (MN-3701) i G.'Holahan, AEOD (MN-9112)

L. Spessard, AEOD (MN-3701)

K. Brockman,.AEOD (MN-3206) 1 S. Rubin, AEOD (MN-5219) t M. Harper, AEOD (MN-9112)

G. Grant, EDO (17G21)

R. Newlin, GPA (2G5)

'i E. Beckjord, RES (NLS-007)

A. Bates, SECY-(16G15)

T. Martin, Region I l

W. Kane, Region I R. Cooper, Region I S. Ebneter, Region II E. Merschoff, Region II S. Vias, Region.II J. Martin, Region III i

E. Greenman, Region III

.i J. Milhoan, Region IV B. Beach, Region IV

~i B. Faulkenberry, Region V K. Perkins, Region V t

bec:

Mr. Sam Newton, Manager Events Analysis Department Institute of Nuclear Power Operations 700 Galleria Parkway.

Atlanta, GA 30339-5957

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4 UNITED STATES o-j NUCLEAR REGULATORY COMMISSION f

WASHINGTON, D.C. 205504001 December 3, 1993

.....f MEMORANDUM FOR:

Brian K. Grimes, Director Division of Operating Reactor Support FROM:

Alfred E. Chaffee, Chief Events Assessment Branch Division of Operating Reactor Support

SUBJECT:

OPERATING REACTORS EVENTS BRIEFING DECEMBER 1, 1993 - BRIEFING 93-45 On December 1, 1993, we conducted an Operating Reactors Events Briefing (93-45) to inform senior managers from offices of the Chairman, ACRS, SECY, OE, NRR, AEOD, and regional offices of selected events that occurred since our last briefing on November 24, 1993. lists the attendees.

presents the significant elements of the discussed events. contains reactor' scram statistics for the week ending November 28, 1993.

No significant events were identified'for input into the NRC Performance Indicator Program.

Sf5 Al red E. Chaffee, Chief Events Assessment Branch Division of Operating Reactor Support

Enclosures:

As stated cc w/ enclosures:

See next page

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ENCLOSURE'l LIST OF ATTENDEES OPERATING REACTORS EVENTS FULL BRIEFING-l(93-45)'

DECEMBER 1, 1993 f

NAME OFFICE NAME OFFICE E. GOODWIN NRR G.

ZECH.

NRR l

E.'BENNER NRR B. GRIMES NRR T.-KOSHY NRR-J. ROE

'NRR K. GRAY NRR J. IBARRA OCM L. TRAN NRR H. ORNSTEIN

.AEOD l

'G.-WEST-NRR J. MATHIS ACRS-S. WEISS

.NRR J. BEALL OE.

A. RAMEY-SMITH

'NRR-K. HART SECY i

T. YAMADA NRR

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i TELEPHONE ATTENDANCE (AT ROLL CALL) i Reaions Resident Inspectors Region.I

' G. Maxwell (McGuire).

j Region II A. MacDougall-(Palo Verde).

I Region III Region IV Region V L

P IIT/AIT Team Leaders Misc.

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i OPERATING REACTORS EVENTS BRIEFING 93-45 LOCATION:-

10 Bil, WHITE-FLINT-WEDNESDAY, DECEMBER 1, 1993 11:00 A.M.

l KEWAUNEE AND STEAM GENERATOR WELDED j

MCGUIRE, UNIT 1 TUBE PLUG LEAKS f

PALO VERDE, UNIT-1 UNCONTROLLED REACTOR COOLANT

-i SYSTEM DRAINDOWN i

i i

l PRESENTED BY:

EVENTS ASSESSMENT BRANCH DIVISION OF OPERATING REACTOR.

j SUPPORT, NRR l

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1 93-45 i

l KEWAUNEE AND MCGUIRE, UNIT 2 STEAM GENERATOR WELDED TUBE PLUG LEAKS l

APRIL 17, 1993 AND OCTOBER 5, 1993 l

PROBLEM 1

WHILE INCREASING POWER AFTER OUTAGES, KEWAUNEE AND MCGUIRE, UNIT 2 IDENTIFIED SIGNIFICA!!T PRIMARY-T0-

-SECONDARY LEAKAGE.

CAUSE LEAKAGE WAS CAUSED BY LEAKING WELDED STEAM GENERATOR (SG)

. TUBE PLUGS.

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SAFETY SIGNIFICANCE i

EVENTS CALL-INTO QUESTION PROGRAMS TO ASSURE QUALITY OF SG j

TUBE PLUGGING OPERATIONS.

SEQUENCE OF EVENTS i

KEWAUNEE:

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04/17/93 PLANT GENERATOR SYNCHRONIZED TO GRID, PRIMARY-

)

T0-SECONDARY LEAKAGE OF 50 GPD.

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4 06/04/93 PLANT SHUT DOWN TO REPAIR LEAK.

LEAK RATE HAD l

INCREASED TO 125 GPD.

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CONTACT:

E. BENNER, NRR/ DORS AIT:

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REFERENCE:

PN0 II-93-053 AND SIGEVENT: IBA MORNING. REPORTS 3-93-0136,

-0173, AND -0179

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KEWAUNEE & MCGUIRE-93-45 o

'L'EAK WAS FROM FIRST WELDED TUBE PLUG INSTALLED IN TUBESHEET IN PREVIOUS OUTAGE.

PLUG REMOVED, THREE CONSUMABLE POLY INSERTS INSTALLED, o

REPLACEMENT PLUG WELDED IN PLACE.

o WELD VISUALLY ACCEPTED AND SG RETURNED TO SERVICE.

i MCGUIRE:

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10/5/93 PLANT ESCALATING IN POWER, OPERATORS DETECTED INCREASING ACTIVITY FROM CONDENSER AIR EJECTOR RADIATION MONITOR.

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CHEMISTRY SAMPLES INDICATE POTENTIAL PRIMARY-TO-SECONDARY LEAKAGE OF UP TO 410 GPD, PLANT SHUTDOWN INITIATED.

10/6/93 PLANT ENTERS MODE 3, HOT STANDBY LEAK WAS FROM A WELDED TUBE PLUG INSTALLED IN TUBESHEET o

IN PREVIOUS OUTAGE.

DISCUSSION 1

KEWAUNEE:

o LICENSEE PULLED THREE COLD LEG TUBES-IN PREVIOUS REFUELING OUTAGE TO PROVIDE INPUT FOR REVISED PLUGGING CRITERION.

PLUGS WERE TO BE WELDED DIRECTLY INTO TUBESHEET.

o

. KEWAUNEE & MCGUIRE 93-45 l

DURING FIRST WELD, AUT0 WELDING MACHINE. UNABLE TO e

MAINTAIN COVER GAS; PERFORMED MANUAL WELD REPAIR.

o MANUALLY WELDED REMAINING TWO PLUGS IN TUBESHEET.

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SG RETURNED TO SERVICE AFTER VISUAL INSPECTION OF 1

PLUGS.

'o WELD REPAIR DID NOT REQUIRE PRF.SSURE-TEST.

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TEST WOULD NOT BE VALID DUE TO USE OF CONSUMABLE POLY INSERTS DURING PLUG INSTALLATION: POLY INSERTS DISSOLVE

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AT ELEVATED TEMPERATURES DURING POWER 0PERATIONS.

1 HCGUIRE:

o LICENSEE PULLED TWO-TUBES IN PREVIOUS OUTAGE TO PROVIDE DA'A FOR PLUGGING CRITERION.

PLUGS WERE MANUALLY WELDED DIRECTLY INTO TUBESHEET; AUTO WELD NOT USED; MANUAL WELD WAS NOT COMPLETE.

o SG RETURNED TO SERVICE AFTER VISUAL INSPECTION OF PLUGS.

o WE!DED PLUGS DID NOT REQUIRE PRESSURE TEST.

o TEST WOULD NOT BE-VALID DUE TO USE OF PLASTIC PLUGS-DURING PLUG INSTALLATION: PLASTIC PLUGS DISSOLVE AT:

350 *F.

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KEWAUNEE & MCGUIRE 93-45 o

IN THE FUTURE LICENSEE WILL USE CERAMIC PLUGS DESIGNED TO BREAK AT-1500 PSI INSTEAD OF PLASTIC PLUGS.

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o SG WAS PRESSURE TESTED TO VERIFY THAT PLUGS WERE LEAK TIGHT AFTER REPAIR OF PLUG WELDS.

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P 93-45 PALO VERDE, UNIT 1 i

UNCONTROLLED REACTOR COOLANT SYSTEM DRAINDOWN NOVEMBER 12, 1993 PROBLEM REACTOR COOLANT SYSTEM (RCS) DRAINDOWN RESULTED IN UNEXPECTED ENTRY INTO REDUCED INVENTORY OPERATION. -

CAUSE OPERATOR DISTRACTION SAFETY-SIGNIFICANCE I

POTENTIAL LOSS OF SHUTDOWN COOLING DISCUSSION RCS LEVEL MAINTAINED BETWEEN JUST BELOW FLANGE-(112 -

q 113 FT) TO WORK ON STEAM GENERATORS.-

1 OPERATORS WERE DRAINING 200 GALLONS 0F RCS ABOUT THREE' o

TIMES A SHIFT BY DIVERTING APPROXIMATELY 110 GPM FROM LOW PRESSURE SAFETY INJECTION (LPSI) PUMP THROUGH THE-MINIMUM FLOW RECIRCULATION PATH TO THE REFUELING WATER j

TANK. (RWT).

o THIS EVOLUTION WAS NORMALLY DONE IN 2 MIN.

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THE INCREASE IN INVENTORY WAS BACK LEAKAGE:FROM l

REFUELING WATER TANK THROUGH THE LPSI: SUCTION ISOLATION, VALVE.

THIS LEAKING VALVE IS NORMALLY OPEN AND CLOSED ONLY-WHEN THAT LOOP IS'USED FOR SHUTDOWN COOLING.

' CONTACT:

- THOMAS KOSHY, NRR/ DORS /0EAB

-AIT: _ liq

REFERENCE:

- MORNING REPORT 5-93-0077 SIGEVENT: IBQ q

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PALO VERDE, UNIT 1 93-45 O'N NOVEMBER 3, 1993 AT 1:20.A.M,.0PERATOR BEGAN ROUTINE o

DRAINDOWN OPERATION T0 REDUCE LEVEL TO 112' 6" AND WAS 1

DISTRACTED PRIOR TO SECURING THE DRAIN.

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o AT 1:28 A.M. SECONDARY OPERATOR OBSERVED RCS LEVEL I

DROPPED TO FIVE FEET AB0VE HOTLEG (INDICATED 108' 5")

l AND SECURED THE DRAINDOWN.

o RCS LEVEL WAS RECOVERED AT 1:32 A.M.

o ACTUAL LEVEL DROP WAS ONLY TO 111' 8" (REDUCED INVENTORY BEGINS AT 111' 0'9.

DRAINDOWN EVOLUTION DID NOT HAVE AN OPERATOR BACKUP.

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FREQUENT DRAINDOWNS COULD HA'!F BEEN AVOIDED BY CLOSING o

A SECOND ISOLATION VALVE.

o PROCEDURE ALLOWED THREE OPTIONS FOR DRAINDOWN PATH.

THE OTHER PATHS WERE THROUGH THE PURIFICATION SYSTEM OR 1

THROTTLING THE SHUTDOWN HEAT EXCHANGER BYPASS VALVE.

o THIS OPERATOR HAD DONE DRAINDOWN OPERATION NINE TIMES IN THE LAST TWO SHIFTS.

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OPERATOR DISTRACTIONS:

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e RESPONDING TO CALL ON VALVE TESTING l

i ATTENDING TO AN OPERATOR REQUEST TO VERIFY RWI e

BORON CALCULATION.

THIS REQUEST WAS MISINTERPRETED AND HE PROCEEDED TO VERIFY THE NUMBERS USED IN THE CALCULATION USING THE TECHNICAL SPECIFICATIONS.

PALO VERDE, UNIT 1 93-45 j

TiiE LICENSEE PROJECTS THE FOLLOWING TO HAVE OCCURRED IF o'

DRAINDOWN CONTINUED-i e

ALARMS AT THREE AND ONE INCH ABOVE MID-LOOP SHUTDOWN COOLING PUMP VORTEXING IN 138 MIN. FROM l

e THE LOWEST LEVEL REACHED.

l 34 MIN. FOR CORE BOILING AFTER LOSING SHUTDOWN COOLING (SDC).

(BASED ON 60.DAYSLAFTER SHUTDOWN AND A CONCURRENT COLD LEG BREAK) t CORE UNC0VERY 4 HOURS AFTER LOSING SDC.

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DURING THIS EVENT THE LICENSEE MAINTAINED THE CAPABILITY FOR GRAVITY FEED AND' CONTAINMENT CLOSURE.

I IMMEDIATE LICENSEE' ACTIONS CREW WAS REMOVED FROM SHIFT AND IS CURRENTLY INVOLVEDL l

o IN HIGH INTENSITY TEAM TRAINING.

o-BRIEFED UNIT 1 OPERATIONAL STAFF ON IMPROVING TEAM WORK-1

& COMMUNICATIONS, EMPHASIZED THE NEED TO~ CONTROL l

CRITICAL' SAFETY FUNCTIONS AND REVIEWED POTENTIAL j

RESULTS OF THE INCIDENT.

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. PLANNED LICENSEE ACTIONS o

UNITS 2 AND 3 PLANT MANAGERS SCHEDULED TO CONDUCT U

BRIEFINGS FOR OPERATIONAL STAFF.

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PALO VERDE, UNIT 1 93-45

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o UNIT 1.0PERATIONS MANAGEMENT WILL CLOSELY-REVIEW THE PERFORMANCE.OF ALL CREWS DURING HIGH INTENSITY TEAM TRAINING AND ENSURE EXPECTATIONS REGARDING COMMUNICATIONS STANDARDS AND TEAMWORK ARE MAINTAINED.

INCORPORATE LESSONS LEARNED INTO OPERATOR TRAINING.

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EVALUATE A DESIGN CHANGE TO ADD AN ALARM WHEN ENTERING.

o REDUCED INVENTORY.

EVALUATE IMPROVEMENTS TO ELIMINATE RWT ISOLATION VALVE o

LEAKAGE.

l FOLLOW UP A MANAGEMENT CONFERENCE WAS HELD IN THE REGION.

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ENCIDSURE. 3 REACTOR SCRAM eeportIng Period: 11/22/93 to 11/28/93

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YTD YTD ABOVE BELOW YTD E.

PtANT & UNIT POWER TYPE-CAUSE COMPLICATIONS} jj] . TOTAL 11/22/93 c'WWA 1 0 SA Equipment Failure No 1 1 2 11/23/93 BYRON 2 99 SA Equipment Faiture No 2 0 2 b Year.To Date (YTD) Totals include Events Within The Calendar Year Indicated By The Erd Date of The Speelfled Reporting Period .e: 10 page:1 12/02/93-

COMPARISON OF WEEKLY SCRAM STATISTICS WITN INDUSTRY AVERAGES PERIOD ENDING ~ 11/28/93 l' kUMBER 1993 1992 1991* 1990* -1989* OF WEEKLY WEEKLY WEEKLY WEEKLY . WEEKLY SCRAM CAU$E SCRAMS AVERAGE AVERAGE AVERAGE AVERAGE AVERAGE (YTD) POWER GREATER THAN OR EQUAL TO 15% EQUIPMENT FAILURE

• 1 1.8 2.6 2.9 3.4 3.1 DESIGN / INSTALLATION ERROR
• 0 0.0 OPERATING ERROR *

.0 0.3 0.2 0.6 0.5 1.0 MAINTENANCE ERROR

• 0 0.5 0.4 ExfERNAL*

0 0.1 OTHER* 0 0.0 0.2 0.1 Subtotal 1 2.7 3.4 3.5 3.9 4.2 POWER LESS THAN 15% EQUIPMENT FAILURE

• 1 0.4 0.4 0.3 0.4 0.3 DESIGN /INSTALLAi!DN ERROR
• O 0.0 OPERATING ERRDR*

O 0.1 0.1 0.2 0.1 0.3 MAINTENANCE ERROR

• 0 0.0 0.1 Ex1ERNAl*

0 0.0 01NER* 0 0.0 0.1 subtotal 1 0.5 0.7 0.5 0.5 0.6 TOTAL 2 3.2 4.1 4.0 4.4 4.8 1993 1992 1991 1990 1989 NO. OF WEEKLY WEEKLY WEEKLY WEEKLY WEEKLY (( RAM TYPE SCRAMS AVERAGE AVERAGE AVERAGE AVERAGE AVERAGE (YTD) -TOTAL AUTOMATIC SCRAMS 2 2.4 3.1 3.3 3.2 3.9 TOTAL MANUAL SCRAMS 0 0.9 1.0 0.7 1.2 0.9 TOTALS MAY DIFFER BECAUSE OF ROUNDING OFF

• Detailed breakdown not in database for 1991 and earlier EXTERNAL cause included in EDU1PMENT FAILURE

. MAINTENAkCE ERROR and DE$1GN/INSTALLAfl0N ERROR causes included in OPERAf!NG ERROR OTHER cause included in EQUIPMENT FAILURE 1991 and 1990 Page: 1 12/02/93

TI.E - PLANT SPECIFIC DATA BASED ON INITIAL REVIEW OF 50.72 REPORTS FOR THE WEEK OF INTEREST. PERIOD IS MIDNIGHT SUNDAY THROUGH MIDNIGHT SUNDAY. SCRAMS ARE DEFINED AS REACTOR PROTECTIVE ACTUATIONS WHICH RESULT IN ROD M7T10N, AND EXCLUDE PLANNED TESTS OR SCRAMS AS PART OF PLANNED SHUTDOWN IN.'ACCORDANCE WITH A PLANT PROCEDURE. THERE ARE 111 REACTORS HOLDING AN OFF. RATING LICENSE. PERSONNEL RELATED PROBLEMS INCLUDE HUMAN ERROR, PROCEDURAL DEFICIENCIES, AND MANUAL STEAM GENERATOR LEVEL CONTROL PROBLEMS. COMPLICATIONS: RECOVERY COMPLICATED BY EQUIPMENT FAILURES OR PERSONNEL ERRORS UNRELATED TO CAUSE OF SCRAM. "OTHER" INCLUDES AUTOMATIC SCRAMS ATTRIBUTED TO ENVIRONMENTAL CAUSES (LIGHTNING), SYSTEM DESIGN, OR UNKNOWN CAUSE. OEAB SCRAM DATA lual and Automatic Scrams for 1987 ------------------ 435 lual and Automatic Scrams for 1988 ------------------ 291 Tual and Automatic Scrams for 1989 ------------------ 252 lua) and Automatic Scrams for 1990 ------------------ 226 lual and Automatic Scrams for 1991 ------------------ 206 sual and Automatic Scrams for 1992 ------------------ 212 lual and Automatic Scrams for 1993 --(YTD 11/28/93)-- 158 t i}}