ML20059K271

Discusses 931027 Operating Reactors Events Briefing Conducted to Inform Senior Managers from Listed Ofcs of Selected Events That Occurred Since Last Briefing on 931020. List of Attendees Encl

ML20059K271
Person / Time
Site:	Beaver Valley, Arkansas Nuclear, Limerick
Issue date:	11/03/1993
From:	Chaffee A Office of Nuclear Reactor Regulation
To:	Grimes B Office of Nuclear Reactor Regulation
References
NUDOCS 9311150268
Download: ML20059K271 (25)

Text

p o aN N OV 0 3 1993 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 OCTOBER 27, 1993 - BRIEFING 93-41 On October 27, 1993, we conducted an Operating Reactors Events Briefing (93-41) to inform senior managers from offices of the Chairman, ACRS, NRR, AEOD, RES, EDO and regional offices of selected events that occurred since our last briefing on >

October 20, 1993. Enclosure 1 lists the. attendees. Enclosure 2 presents the significant elements of the discussed events.

Enclosure 3 contains reactor scram statistics for the week ending October 24, 1993. No significant events were identified for input into the NRC Performance Indicator Program.

Edward Goodwin

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

Enclosures:

As stated DISTRIBUTION:

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T. Murley, NRR (12G18) R. Bevan'(PDIV-1)

F. Miraglia, NRR (12G18) W. Beckner (PDIV-1))

F. Gillespie, NRR (12G18) G. Edison (PDI-3) l J. Partlow, NRR (12G18) W. Butler (PDI-3)

S. Varga, NRR (14E4) F. Rinaldi (PDI-2)

J. Calvo, NRR (14A4) L.-Nicholas (PDI-2)

G. Lainas, NRR (14H3)

J. Roe, NRR (13E4)

J. Zwolinski, NRR (13H24)

E. Adensam, NRR (13E4)

W. Russell, NRR (12G18)

J. Wiggins, NRR (7D26)

A. Thadani, NRR (8E2)

S. Rosenberg, NRR (10E4)

C. Rossi, NRR (9A2)

B. Boger, NRR (10H3)

F. Congel, NRR (10E2)

D. Crutchfield, NRR (11H21)

W. Travers, NRR (11B19)

D. Coe, ACRS (P-315)

E. Jordan, AEOD (MN-3701)

G. Holahan, AEOD (MN-9112)

L. Spessard, AEOD (MN-3701)

K. Brockman, AEOD (MN-3206)

S. Rubin, AEOD (MN-5219)

M. Harper, AEOD (MN-9112)

G. Grant, EDO (17G21)

R. Newlin, GPA (2G5)

E. Beckjord, RES (NLS-007)

A. Bates, SECY (16G15)

T. Martin, Region I W. Kane, Region I R. Cooper, Region I S. Ebneter Region II E. Merschoff, Region II S. Vias, Region II J. Martin, Region III E. Greenman, Region III J. Milhoan,' Region IV B. Beach, Region IV B. Faulkenberry, Region V K. Perkins, Region V bec: Mr. Sam Newton, Manager Events Analysis Department Institute of Nuclear Power Operations 700 Galleria Parkway Atlanta, GA 30339-5957

., S E'cq O s+ . UNITED STATES 3JN)eE 8 NUCLEAR REGULATORY COMMISSION

1. s) v [f,8 45 WASHINGTON, D.C. 20555 g,

NOV 0 31993 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 OCTOBER 27, 1993 - BRIEFING 93-41 On October 27, 1993, we conducted an Operating Reactors Events Briefing (93-41) to inform senior managers from offices of the Chairnan, ACRS, NRR, AEOD, RES, EDO and regional offices of selected events that occurred since our last briefing on October 20, 1993. Enclosure I lists the attendees. Enclosure 2 presents the significant elements of the discussed events.

Enclosure 3 contains reactor scram statistics.for the week ending October 24, 1993. No significant events were identified for input into the NRC Performance Indicator Program.

9 6 h1 Alfred E. Chaffee, Chief Events Assessment Branch ,

Division of Operating  ;

Reactor Support l

Enclosures:

As stated cc w/ enclosures:

See next page E

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-ENCLOSURE 1  !

i LIST OF ATTENDEES

• i c'T 'ATING REACTORS EVENTS FULL BRIEFING - (93-41)

OCTOBER 27, 1993

-f NAME OFFICE NAME OFFICE 1 i

~!

A. CHAFFEE NRR L. NICHOLSON NRR i E.'BENNER NRR S. LONG- NRR -r R. BENEDICT NRR R.-SCHAAF NRR~ l D.'SKEEN NRR G. EDISON NRR R. DENNIG NRR T. YAMADA- NRR '{

K. GRAY NRR G.-ZECH NRR ,

E. GOODWIN -NRR F. RINALDI NRR  !

S. WEISS NRR S.'VARGA ~NRR 'l T. ALEXION NRR J. MATHIS- A C R S'-

R. LOBEL NRR V. BENAROYA

'{

AEOD~  ;{

J. HICKMAN NRR W. MINNERS RES R. BEVAN NRR B..MCCABE 'OEDO-  !

B. GRIMES NRR J. IBARRA 'OCM/IS" -j l

. TELEPHONE ATTENDANCE  !

(AT ROLL CALL) '

-l

. Rections Resident Inspectors

,j Region I T. Easlick-(Limerick) i Region II- S. Greenlee (Beaver Valley)

-Region III .!-

Region IV  !;

l

.i IIT/AIT Team Leaders Misc.

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ENCLOSURE 2- -

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-l OPERATING REACTORS EVENTS BRIEFING 93-41 j LOCATION: 10 Bil, WHITE. FLINT ~ l WEDNESDAY, OCTOBER 27, 1993 11:00 A.M.

J i

ARKANSAS NUCLEAR ONE, POTENTIAL TO RENDER: SAFETY .

UNITS.1 AND 2 INJECTION INOPERABLE DUE T0 SUMP  !

BLOCKAGE  !

5 BEA.VER VALLEY, VAi_VE. STEM UNCOUPLING FROM OPERATOR  !

UNIT 2 i LIMERICK, REACTOR SCRAM CAUSED BY ' SITE  !

UNIT 1 EXCAVATION WORK -l i

i i

. PRESENTED BY: EVENTS 1 ASSESSMENT BRANCH i DIVISION OF OPERATING REACTOR SUPPORT, NRR 1

i

~ _-.1 _ _.. - -

. . . . _ m

, ,[ 93 ARKANSAS NUCLEAR ONE, UNITS 1 AND 2 l POTERTIAL TO RENDER SAFETY INJECTION-INOPERABLE DUE TO SUMP BLOCKAGE

,. OCTOBER 14, 1993 i i

PROBLEM POTENTIAL TO RENDER SAFETY. INJECTION -(SI) AND CONTAINMENT g SPRAY (CS) INOPERABLE DURING A DESIGN BASIS LOSS OF COOLANT ACCIDENT (LOCA).  ;

1 IAUSE D

UNSCREENED OPENINGS IN REACTOR BUILDING SUMP COULD ALLOW FIBERGLASS INSULATION TO BLOCK SI VALVES AND CS N0ZZLES.

SAFETY SIGNIFICANCE SI AND CS'COULD HAVE BEEN INCAPABLE OF PERFORMING THEIR RECIRCULATION FUNCTIONS FOLLOWING A DESIGN BASIS LOCA.

DISCUSSION UNIT 1 10/01: PLANT IN-COLD SHUTDOWN, LICENSEE IDENTIFIES SEVERAL:

L UNSCREENED OPENINGS INTO REACTOR BUILDING SUMP:

e 22 SCUPPER HOLES AT BASE OF SUMP' CURB l

e e

FOUR CONDUIT / PIPE PENETRATIONS SUMP CURB PENETRATION

[ i L e TWO SUMP SCREEN TEARS 1 e REACTOR BUILDING DRAINAGE SYSTEM I CONTACT: E. BENNER, NRR/0EAB 'AIT: RQ_

REFERENCES:

10 CFR 50.72 #26221 AND SIGEVENT: IBD_ i

1. 26261 '

l

. . . . ~ . . . - . . , _ . _ _ - , .

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- ANO,-UNITS 1 AND.2 93-41 10/14: ENGINEERING EVALUATION DETERMINES LOW PRESSURE INJECTION (LPI) COULD HAVE BEEN RENDERED IN0PERABLE DURING RECIRCULATION PHASE OF DESIGN BASIS LOCA, BASED ON:

e FIBERGLASS INSULATION DISLODGED FROM REACTOR COOLANT SYSTEM PIPING e

INSULATION MIGRATES T0. REACTOR BUILDING SUMP e

INSULATION BLOCKS FLOW THROUGH LPI COOLER OUTLET VALVES e

COOLER BYPASS VALVES -(AIR OPERATED VALVES)

CANNOT BE OPENED SINCE' INSTRUMENT AIR 4 COMPRESSORS NOT AVAILABLE DURING DESIGN-BASIS LOCA WITH ONLY ONE OPERABLE DIESEL GENERATOR AND LOSS-OF-OFFSITE PmdER' (LOOP).

DEFICIENCIES CORRECTED DURING OUTAGE BY BLOCKING SCREEN OPENINGS.WITH PLATE AND INSTALLING SCREENS OVER HOLES.

LICENSEE ESTIMATES THAT 11-15 FT '0F FIBROUS MATERIAL WOULD MIGRATE-INTO SUMP DURING DESIGN BASIS'LOCA WITH IDENTIFIED OPENINGS; 1/2 FT NEEDED TO CLOG COOLER OUTLET VALVES. .

UNIT 2 (ALL TIMES ARE CDT) 10/22: UNIT AT 100% POWER,: INSPECTION IDENTIFIES SEVERAL UNSCREENED OPENINGS INTO REACTOR BUILDING SUMP:.

e SEVEN 1" X 3" HOLES IN SUMP SCREEN GROUT

. ANO, UNITS 1 AND 2 93-41 17:19: LICENSEE CONSERVATIVELY DECLARES RECIRCULATION SUMP IN0PERABLE, ENTERS TECHNICAL SPECIFICATION 3 (TS) 3.0.3, OPERABILITY EVALUATION IS ONGOING.

17:50: LICENSEE CONTACTS NRC TO REQUEST ENFORCEMENT DISCRETION RATHER THAN SHUT DOWN 20:13: ENFORCEMENT DISCRETION GRANTED BY NRC, LICENSEE >

GIVEN 36 HOURS TO CORRECT CONDITION 10/23: EXITED TS 3.0.3 AT 03:22 INSPECTION OF SUMP REVEALED A FLASHLIGHT APPARENTLY LEFT FROM THE PREVIOUS REFUELING OUTAGE; HOWEVER VORTEX PREVENTION SCREENS OVER RECIRCULATION SUCTION PIPING WO HAVE PREVENTED TRANSPORT INTO SUCTION PIPING.

FOLLOWUP LICENSEE ACTIONS:

• IN RESPONSE TO GENERIC COMMUNICATIONS, LICENSEE REVISED UNIT 1 " PLANT HEATUP AND PRECRITICALITY CHECKLIST" PROCEDURE TO ADD THE FOLLOWING STATEMENT:

" PERFORM A VISUAL INSPECTION OF THE REACTOR BUILDING SUMP, ITS GRATING, LPI SUCTION INLETS AND THE GENERAL AREA. ENSURE THAT NO TRASH, RAGS OR OTHER DEBRIS IS PRESENT WHICH WOULD INTERFERE OR RESTRICT THE LPI SUCTION LINE, OR CLOG GRATINGS AND INSTRUMENT LINES"

i

'ANO, UNITS 1 AND 2 93-41 o- PREVIOUS LICENSEE INSPECTIONS HAVE FOCUSED ON j '

GENERAL AREA CLEANLINESS VERSUS GRATING INTEGRITY.

NRC ACTIONS: )

1 e- REGION IV HAS CONDUCTING A SPECIAL INSPECTION.

e REGION IV AND CONTAINMENT SYSTEMS & SEVERE ACCIDENT BRANCH ARE PREPARING AN INFORMATION NOTICE ON THIS q EVENT. )

l PAST GENERIC C0l#4UNICATIONS:

e GENERIC LETTER 85-22: " POTENTIAL FOR LOSS OF POST- 1 LOCA RECIRCULATION CAPABILITY DUE TO INSULATION- l DEBRIS BLOCKAGE." j e INFORMATION NOTICE 88-28: " POTENTIAL FOR LOSS OF

' POST-LOCA RECIRCULATION CAPABILITY DUE TO j

. INSULATION DEBRIS BLOCKAGE." q e INFORMATION NOTICE 89-77: " DEBRIS IN CONTAINMENT. I EMERGENCY SUMPS & INCORRECT SCREEN CONFIGURATION."  !

e INFORMATION NOTICE 92-71: " PARTIAL PLUGGING 0F .)

SUPPRESSION POOL. STRAINERS AT A FOREIGN BWR."  !

• INFORMATION NOTICE 93-34: . " POTENTIAL. FOR LOSS'0F EMERGENCY COOLING FUNCTION DUE TO A COMBINATION OF j OPERATIONAL'AND' POST-LOCA DEBRIS IN CONTAINMENT." R

.]

e BULLETIN 93-02: " DEBRIS PLUGGING OF EMERGENCY-CORE COOLING SUCTION STRAINERS." l 1

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BEAVER VALLEY, UNIT 2 i VALVE STEM UNCOUPLING FROM OPERATOR i OCTOBER 17, 1993 PROBLEM l NO FLOW FROM RECIRCULATION SPRAY PUMP WHEN TESTED. j CAUSE. j PUMP SUCTION VALVE STAYED CLOSED BECAUSE VALVE STEM HAD i UNC00 PLED FROM MOTOR OPERATOR. 1 j

SAFETY SIGNIFICANCE il POSSIBLY DEGRADED POST-ACCIDENT COOLING CAPABILITY (VALVES ARE NORMALLY OPEN DURING PLANT OPERATION).  ;

DISCUSSION I e

VALVE STEM.UNC00PLING IDENTIFIED BY VISUAL INSPECTION. j A

e PROBLEM COMMON TO ALL FOUR RECIRCULATION SPRAY PUMP -!

SUCTION VALVES.  !

~

- e 12-INCH. MOTOR-OPERATED BUTTERFLY VALVES WITH LIMITORQUE j HBC-1 OPERATORS.

• CYLINDRICAL SPLINE ADAPTOR COUPLES OPERATOR DRIVE GEAR i TO VALVE STEM. j L

o SPLINE ADAPTOR FELL DOWN THROUGH'OVER-SIZED HOLES IN  !

OPERATOR MOUNTING PLATE AND VALVE BONNET.

l l

CONTACT: R. BENEDICT, NRR/0EAB AIT: NO

REFERENCE:

MORNING REPORT DATED 10/19/93 SIGEVENT:- TBD q

-~=,-.-.Le.---- * * , -

. E BEAVER VALLEY, UNIT 12 - 93-41 e MOUNTING PLATE AND BONNET WERE PROVIDED BY VALVE'VENDORL (HENRY PRATT).

• HOUNTING PLATE AND-BONNET' HOLES WERE 1/2 INCH WIDER:

TRAN DESIGN SPECIFICATION.

.e LICENSEE MEASURED MOUNTINF PLATE AND BONNET-HOLES FOR' ALL HENRY PRATT BUTTERFLY VALVES.

• PROBLEM EXISTS ONLY ON THE FOUR RECIRCULATION SPRAY PUMP SUCTION VALVES.

e LICENSEE'S TEMPORARY FIX IS A SPLIT RETAINING CLAMP'ON-VALVE STEM.

• LICENSEE WILL NOTIFY INDUSTRY.

• LICENSEE IS PREPARING 10 CFR 21 SUBMITTAL.

FOLLOWUP e VENDOR INSPECTION BRANCH IS HANDLING THIS UNDER 10 CFR PART 21.

e OEAB/ REGION I CONSIDERING INFORMATION NOTICE.

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, _ *~i LIMERICK, UNIT 11 REACTOR SCRAM CAUSED BY SITE EXCAVATION WORK-SEPTEMBER 7, 1993 :l i

PROBLEM REACTOR SCRAM AND PARTIAL LOSS OF 0FFSITE POWER.

l CAUSE j INADEQUATE CONTROL OF SITE EXCAVATION WORK.

SAFETY SIGNIFICANCE ,

UNNECESSARY CHALLENGES TO ENGINEERED SAFETY FEATURE. (ESF) 'I COMPONENTS AND SYSTEMS. j i

DISCUSSION  !

e 2:32 P.M. - ONE OF TWO 0FFSITE POWER SUPf1.IES WAS LOST-  !

DUE TO.A DIFFERENTIAL OVERCURRENT CONDITION ON THE 10 l

. STATION AUXILIARY BUS.  !

e ALL PLANT SAFEGUARD BUSES TRANSFERRED TO THE ALTERNATE l OFFSITE SOURCE. TWO EDGs FROM EACH UNIT STARTED AND RAN UNLOADED, AS DESIGNED.

e 2:33 P.M. - THE REACTOR SCRAMED ON LOW LEVEL DUE TO l LOSS OF CONTROL SIGNAL TO TWO 0F THREE FEEDWATER PUMPS. j FOLLOWING THE SCRAM, LEVEL WAS RESTORED BEFORE ANY q EMERGENCY CORE COOLING SYSTEM ACTUATIONS. OCCURRED.  ;

I l

-CONTACT: D. SKEEN, NRP '0EAB- AIT: _ND_ i 10 CFR 50.72 #26031

REFERENCE:

SIGEVENT: NO j

LIMERICK, UNIT 1 93-41 j 2:37 P.M. OPERATOR NOTICED NON-SAFETY RELATED- 1~

MOTOR CONTROL CENTER (NCC) FEEDER BREAKER-DID NOT RECLOSE-FOLLOWING REENERGIZATION OF THE D11 l SAFEGUARD BUS AND MANUALLY CLOSEDETHE BREAKER. j q

THE LOSS OF FEEDWATER CONTROL. SIGNAL WAS CAUSED BY- l THE FAILURE 0F THE MCC BREAKER TO AUTOMATICALLY RECLOSE.

e 7:00 P.M. - ALL SITE EXCAVATION WORK WAS STOPPED AFTER LICENSEE IDENTIFIED POTENTIAL CORRELATION BETWEEN WORK INVOLVING FIRE HYDRANT NO. 5 AND THE SCRAM.

e LOSS OF THE 10 STATION AUXILIARY BUS WAS CAUSED BY-WORKERS CHIPPING CONCRETE DUCT BANK AROUND 13.8 KV CABLE DURING' SHORING ENHANCEMENT WORK AT FIRE HYDRANT NO. 5.

• A CONTRACTOR WORK GROUP PERFORMING REPAIR WORK:0F THE SITE FIRE PROTECTION SYSTEM INSTALLED INADEQUATE-SHORING AT SOME OF THE EXCAVATION SITES.

e THE STATION WORK GROUP PERFORMING THE BACKFILL.OF.THE  ;

TRENCHES WENT BEYOND THE ORIGINAL SCOPE OF WORK BY PERFORMING SHORING ENHANCEMENTS AND INSTALLING THRUST i BLOCKS. -

FOLLOWUP e LICENSEE IDENTIFIED SEVERAL CAUSES THAT CONTRIBUTED TO i THE EVENT: u INADEQUATE CONTROL OF NON-ROUTINE WORK UNCLEAR SUPERVISION AND WORKER EXPECTATIONS ~

f LIMERICK, UNIT 1 93-41 INADEQUATE CONTROL OF EXCAVATIONS  !

INADEQUATE. SHORING PROCEDURE i e THE LICENSEE COULD NOT DETERMINE THE- CAUSE OF THE HCC I t

FEEDER BREAKER FAILURE TO RECLOSE. THE RECLOSURE-CIRCUIT COMPONENTS:WERE REPLACED.

e REGION I DISPATCHED A TWO MAN TEAM TO PERFORM A SPECIAL j '

INSPECTION.

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FIRE PUMP :

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ENCLOSURE 3 i

REACTOR SCRAM Reporting Period: 10/18/93 to 10/24/93 YTD YTD ABOVE BELOW ~~ YTD pfli Ptaw? 8 tutit PMP lYP1 f,Alffi COMPLfCATIO8tS $ $ $$

10/18/93 SEQUOYAN 2 0 SM Equipment Failure N0 0 1 1-10/22/93 MatCM 1 100 SM Eg.sipment Fellure so 3 1 4 10/24/93 OCOWEE 2 100 SA Ecpipnent Failure k0 2 1 .3 10/24/93 $EQUOTAN 2 0 SM fcNipraent Failure NO O 2 2 tote:

Tear to Oste (YTD) totals incluse Events Within The Calendar Year Indicated 8y The Erd Date Of the specified Reporting de ETS 10 p*De:1 10/27/93

+ # .. '

l

.e COMPARISDN OF WEEKLY SCRAM STATISTICS WITH INDUSTRY AVERAGES

• PERIOD ENDING 10/24/93 NUMBER 1993 1992 1991* 1990* 1969*

+

OF WEECLT WEEKLY WEEKLY WEEKLT WEEKtY SCRau CAUSE SCRAMS

{

AVERACE AVERAGE AVERAGE AVERAGE AVERAGE (YTC) l POWER GREATER ThAN OR EQUAL TO 15%

EDUIPMENT FAILURE

• 2 1.8 2.6 2.9 3.4 3.1 DESIGh/!NSTALL ATIDW ERRDR* 0 0.0 - - . -

OPERATING ERROR

• 0 0.3 0.2 0.6 0.5 1.0 I MAINTEhANCE ERROR

• O 0.6 0.4 - - -

EXTERbAL* 0 0.1 - - - -

OTHER* 0 0.0 0.2 - -

0.1 i subtotal 2 2.8 3.4 3.5 3.9 4.2 I

POWER LES$ ThAN 151 i EDVIPMENT F AILURE* 2 0.4 0.4 0.3 0.4 0.3 DESIGN /lkSTALLATIDN ERRDR* O 0.0 - - - -  !

DPERAtlkG ERROR

• 0 0.2 0.1 0.2 0.1 0.3  !

KAthTEhAhCE ERRDR* O 0.0 0.1 - - -

EXTERNAL

• 0 0.0 - - - -

OTHER* 0 0.0 0.1 - - * #

l Subtotal 2 0.6 0.7 0.5 0.5 0.6 &

T0TAL 4 3.4 4.1 4.0 4.4 4.8 1

1993 1992 1991 1990 1989 t

No. OF WEEKLY bEEKLY WEEKLY WEEKLY WEEKLY l 1 $CPau type -

SCRAMS AVERAGE AVERAGE AVERAGE AVERAGE AVERAGE j (YTC) 1 TOTAL AUTDMATIC SCRAMS 1 2.5 3.1 3.3 3.2 3.9 i

TDTAL MANUAL SCRAM 5 3 0.9 i 1.0 0.7 1.2 0.9  !

I TOTALS MAY DIFFER BECAUSE OF ROUNDlWG OFF

• Detailed treakdown not in databese for 1991 and earlier

. EKTERhAt cease included in EQUIPMENT FAILURE

- MAINTEhAhCE ERROR and OESIGN/INSTALLATIDN ERROR Causes included in OPERATING ERROR  ;

OTHER cesse included in EQu!PMENT FAILURE 1991 and 1990 i

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ETS-14 Page: 1 10/27/93  !

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< NOTES

.1.

PLANT SPECIFIC DATA BASED ON INITIAL REVIEW OF 50.72 REPORTS FOR THE WEEK OF INTEREST. PERIOD IS MIDNIGHT SUNDAY THROUGH MIONIGHT SUNDAY.

SCRAMS ARE DEFINED AS REACTOR PROTECTIVE ACTUATIONS WHICH RESULT IN ROD MOTION, AND EXCLUDE PLANNED TESTS OR SCRAMS AS PART OF PLANNED SHUTDOWN IN ACCORDANCE WITH A PLANT PROCEDURE. THERE ARE 111 REACTORS HOLDING AN '

OPERATING LICENSE. I 2.

PERSONELL RELATED PROBLEMS INCLUDE HUMAN ERROR, PROCEDURAL DEFICIENCIES, AND MANUAL STEAM GENERATOR LEVEL CONTROL PROBLEMS.

3.

COMPLICATIONS: RECOVERY COMPLICATED BY EQUIPMENT FAILURES OR PERSONNEL ERRORS UNRELATED TO CAUSE OF SCRAM.

4.

"OTHER" INCLUDES AUTOMATIC SCRAMS ATTRIBUTED TO ENVIRONMENTAL CAUSES (LIGHTNING), SYSTEM DESIGN, OR UNKNOWN CAUSE.

OEAB SCRAM DATA Manual and Automatic Scrams for 1987 ------------------ 435 Manual and Automatic Scrans for 1988 ------------------ 291 Manual and Automatic Scrans for 1989 ------------------ 252 Manual and Automatic Scrams for 1990 ------------------ 226 Manual and Automatic Scrams for 1991 ------------------ 206 Manual and Automatic Scrams for 1992 ------------------ 212 '

Manual and Automatic Scrams for 1993 --(YTD 10/24/93)-- 146 e

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