ML20059H035

Summary of Operating Reactors Meeting 93-40 on 931020

ML20059H035
Person / Time
Site:	Beaver Valley
Issue date:	10/28/1993
From:	Chaffee A Office of Nuclear Reactor Regulation
To:	Grimes B Office of Nuclear Reactor Regulation
References
OREM-93-040, OREM-93-40, NUDOCS 9311090262
Download: ML20059H035 (26)

Text

,h N

.0LT 2 B 1993 l

l MEMORANDITM 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 20, 1993 - BRIEFING 93-40 On October 20, 1993, we conducted an Operating Reactors Events Briefing (93-40) to inform senior managers from offices of the Chairman, ACRS, NRR, AEOD, OIP, EDO and regional offices of selected events that occurred since our last briefing on October 13, 1993. lists the attendees.

presents the significant elements of the discussed events. contains reactor scram statistics for the week ending October 17, 1993.

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

Origin?! Eipd W Alfred E.

Chaffee, Chief Events Assessment Branch Division of Operating Reactor Support

Enclosures:

As stated DISTRIBUTION:

RCentral. Files a cc w/ enclosures:

PDR See next page LKilgore, SECY EAB R/F KGray RDennig EGoodwin DSkeen EBenner TKoshy i

4 4 EAB/ DORS EAB bORS

.Graf

,S EGoodwin AChaffee

/gry /93 10/g /93 10g7/93 OFFICIAL RECORD COPY DOCUMENT NAME:

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aW i E UNITED STATES

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NUCLEAR REGULATORY COMMISSION

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WASHINGTON, D.C. 205540001 0Cl 2 810 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 20, 1993 - BRIEFING 93-40 On October 20, 1993, we conducted an Operating Reactors Events Briefing (93-40) to inform senior managers from offices of the Chairman, ACRS, NRR, AEOD, OIP, EDO and regional offices of selected events that occurred since our last briefing on October 13, 1993. lists the attendees.

presents the significant elements of the discussed events. contains reactor scram statistics for the week ending October 17, 1993.

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

$$I ('

Alfred E.

Chaffee, Chief Events Assessment Branch Division of Operating Reactor Support

Enclosures:

As stated cc w/ enclosures:

See next page

g cc:

T. Murley, NRR (12G18)

W. Huffman (AEOD)

F. Miraglia, NRR (12G18)

J. Giitter (AEOD)

F.

Gillespie, NRR (12G18)

G. Edison (PDI-3)

J.

Partlow, NRR (12G18)

W. Butler (PDI-3)

S. Varga, NRR (14E4)

J.

Calvo, NRR (14A4)

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 (2GS)

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 i

---um

.-iims

--- ---i

ENCLOSURE 1 LIST OF ATTENDEES OPERATING REACTORS EVENTS FULL BRIEFING (93-40)

OCTOBER 20, 1993 l

.NAME OFFICE NAME OFFICE A.

CHAFFEE NRR N. HUNEMULLER NRR T. KOSHY NRR E. BENNER NRR K. GRAY NRR C.

GRIMES NRR M.

CULLINGFORD NRR J.

PARTLOW NRR C. MCCRACKEN NRR J. CALLAN NRR G.

MARCUS NRR S.

VARGA NRR E. GOODWIN NRR W.

BUTLER NRR S.

ROSENBERG NRR W.

HUFFMAN AEOD P. MADDEN NRR J.

GIITTER AEOD A.

PAL NRR H. ORNSTEIN AEOD C.

BERLINGER NRR G.

HOLAHAN AEOD R.

LANDRY NRR J.

IBARRA OCM/IS E. THROM NRR J. MA'-

IS ACRS D. SCALETTI NRR S. MORRIS RI G.

EDISON NRR K.

HENDERSON OIP T. YAMADA NRR L. PLISCO OEDO TELEPHONE ATTENDANCE (AT ROLL CALL)

Recions Resident Inspectors Region I S. Greenlee (Beaver Valley)

Region III Region IV Region V IIT/AIT Team Leaders Misc.

NRC Technical Training Center l

l

ENCLOSURE 2 OPERATING REACTORS EVENTS BRIEFING-93-40 LOCATION:

10 B11, WHITE FLINT WEDNESDAY, OCTOBER 20, 1993, 11:00 A.M.

FOREIGN REACTOR STATION BLACK 0UT

[ PROPRIETARY INFORMATION]

(UPDATE) l l

BEAVER VALLEY, UNIT 1 PLANT TRIP AND LOSS OF 0FFSITE POWER PRESENTED BY:

EVENTS ASSESSMENT BRANCH DIVISION OF OPERATING REACTOR SUPPORT, NRR i

1 l'

l 93-40 BEAVER VALLEY, UNIT 1 PLANT TRIP AND LOSS OF 0FFSITE POWER l

OCTOBER 12, 1993 l

PROBLEM UNIT 1 TRIP AND LOSS OF 0FFSITE POWER (LOOP) TO BOTH UNITS l

CAUSED BY SWITCHYARD MAINTENANCE.

UNIT 2 WAS SHUTDOWN AND l

l DE-FUELED.

CAUSE INADEQUATE WORK CONTROL RESULTED IN SPURIOUS LOAD

~

j SHEDDING.

j i

{

SAFETY SIGNIFICANCE UNANTICIPATED PLANT TRANSIENT AND CHALLENGES TO SAFETY j

SYSTEMS.

SEQUENCE OF EVENTS

~

i e

UNIT 1 WAS AT FULL POWER.

UNIT 2 WAS SHUT DOWN AND DE-1 FUELED.

A MAINTENANCE CREW WAS PERFORMING POST MAINTENANCE CHECKS ON AUXILIARY CONTACTS ON ONE OF TWO l

UNIT 2 MAIN OUTPUT BREAKERS (BK #352).

)

i e

THIS BREAKER WAS TAGGED OUT AT THE HIGH VOLTAGE SIDE

)

BUT CONTROL POWER (DC) REMAINED AVAILABLE.

l 1

CONTACT:

T. KOSHY, NRR/ DORS /0EAB AIT: R0 i

REFERENCE:

10 CFR 50.72 #26209 SIGEVENT: TBD i

j l

BEAVER VALLEY, UNIT 1 93-40 e

WHILE CHECKING OUT UNIT 2 MAIN BREAKER AUXILIARY l

CONTACTS, THE MAINTENANCE CREW INADVERTENTLY ACTUATED THE SUBSTATION UNDERFREQUENCY RELAYS.

j e

THIS OCCURRED WHILE CHECKING AUXILIARY CONTACTS FOR POSSIBLE MISALIGNMENT BY PLACING A LOW IMPEDANCE MULTIMETER, USING A CONTINUITY SCALE, ACROSS EACH OF THE CONTACTS.

THE TECHNICIAN ESTABLISHED A PATH FOR 125 Voc POWER, THROUGH THE METER, TO THE SUBSTATION UNDERFREQUENCY I

TRIPPING RELAYS.

e THE UNDERFREQUENCY RELAYS RESPONDED PER DESIGN,

)

TRIPPING OPEN TEN BREAKERS IN THE BEAVER VALLEY SUBSTATION AND CAUSING A 90% LOAD REDUCTION ON THE UNIT i

1 MAIN GENERATOR AND ISOLATION FROM THE GRID.

e THE UNIT 1 RESPONSE TO THE LOAD REDUCTION AND ISOLATION WAS A RAPID INCREASE IN TURBINE SPEED.

THE INCREASE IN i

MAIN GENERATOR OUTPUT FREQUENCY CAUSED THE REACTOR COOLANT PUMPS TO SPEED UP.

THIS CAUSED INCREASED REACTOR COOLANT FLOW AND A SUBSEQUENT REACTOR POWER 1

EXCURSION.

THE REACTOR TRIPPED ON HIGH NEUTRON FLUX l

RATE.

3 MILLISECONDS BEFORE THE REACTOR TRIP, THE TURBINE e

TRIPPED ON MECHANICAL OVERSPEED (110%).

THE TURBINE ELECTRICAL OVERSPEED TRIP ALSO FUNCTIONED WHEN THE TURBINE REACHED 111% SPEED.

l

-... w

I BEAVER VALLEY, UNIT 1 93-40 5

e THE SUBSTATION LOAD SHEDDING AND THE UNIT 1 TRIP CAUSED A LOOP AT BOTH UNITS.

OFFSITE POWER WAS RECOVERED AT BOTH UNITS WITHIN NINE MINUTES.

ALL SAFETY SYSTEMS AT UNIT 1 FUNCTIONED AS DESIGNED.

UNIT 2 HAD ONE AVAILABLE EMERGENCY DIESEL GENERATOR THAT STARTED AND SEQUENCED POWER TO NECESSARY SHUTDOWN LOADS.

l PLANT REC 0VERED FORCED CIRCULATION WITHIN APPR0XIMATELY e

10 MINUTES.

]

DISCUSSION j

e THE FUNCTION OF THE UNDERFREQUENCY RELAYS IS TO ISOLATE j

DESIGNATED LOADS WHEN GRID FREQUENCY DROPS DUE TO SYSTEM OVERLOAD.

THE INTENT WAS TO SHED EN0 UGH LOAD TO RESTORE GRID FREQUENCY AND THUS ALLOW THE BEAVER VALLEY UNITS TO REMAIN ONLINE.

THE LICENSEE IS REEVALUATING THE DESIGN.

e THE LICENSEE MADE A FOUR HOUR REPORT TO THE OPERATIONS CENTER BECAUSE OF THE REACTOR TRIP AND ENGINEERED SAFETY FEATURE ACTUATION (EDG START).

l e

THE LICENSEE'S EMERGENCY PLAN DID NOT REQUIRE DECLARATION OF AN UNUSUAL EVENT (UE) FOR THIS OCCURRENCE.

THE LICENSEE IS NOW REEVALUATING THEIR j

CRITERIA FOR EMERGENCY CLASSIFICATIONS FOR A LOOP USING THE NUMARC GUIDANCE.

2 t

BEAVER VALLEY, UNIT 1 93-40 e

THE CONDITIONAL CORE DAMAGE PROBABILITY (CCDP) IS ESTIMATED TO BE 6E-05 ASSUMING PLANT CENTERED (SWITCHYARD INITIATED) LOOP, 2 HOUR BATTERY DEPLETION TIME, AND WESTINGHOUSE OLD REACTOR COOLANT PUMP 0-RING i

DESIGN.

e DOMINANT ACCIDENT SEQUENCE IS LOOP WITH FAILURE OF EDGs j

AND SUBSEQUENT SEAL LOSS OF COOLANT ACCIDENT.

e UNIT 1 IS IN COLD SP"TDOWN TO FIX A MINOR REACTOR C0OLANT SYSTEM (RCS, LEAK IDENTIFIED FOLLOWING SHUTDOWN.

A UE WAS DECLARED FOR THE RCS LEAKAGE.

FOLLOWUP REGION I IS MONITORING THE LICENSEE'S SHORT TERM AND LONG

)

TERM ACTIONS.

N

BRIEFING 93-40 BEAVER VALLEY, UNIT 1 laev.. mesi waghtt g, nt ut t

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~

e a

ENCLOSURE 3 REACTOR SCRAM Reporting Period: 10/11/93 to 10/17/93 YTD YTD ABOVE BELOW YTD

[,Al[

P'. Aw' ! LIWIT POWER E

CAUSE COMPLfCAff0ws M

E 10/12/93 BEAVER VALLEY 1 100 SA Maintenance Error YES 1

0 1

10/14/93 RIVER BEND 1 95 SA Equipment fatture wo 2

0 2

t P

P k

DESCRIPTIDW OF COMPLICAT!Dh(S) 10/11/93 10 10/17/93 g

pf]T, CPPLICATIONS T

BEAVER VA;tEY 1

LOSS OF OFFSITE PC9ER CAUSED SCRAM AeID LASTED 1.25 MOURS.

i i

hete: 'eae Tc Cate (YTC) Totals inctuck Eventt Within the Calendar Year Indicated By The End Date of The Specified Reporting Period E15-10 page:1 10/22/93

I i

COMPARISON OF WEEKLY SCRAM STATISTICS WITH INDUSW Y AVERAGES PERIOD E 61NG 10/17/93 NUMBER 1993 1992 1991*

1990*

1989*

OF WEEKLY WEEKLY WEEKLY WEEKLY WEEKLY SCRAM CAUSE 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 /lWSTALLATION ERROR

• O 0.0 CPERATING ERROR

• O 0.3 0.2 0.6 0.5 1.0 MAINTEbANCE ERROR

• 1 0.6 0.4 EXTEFhAL*

0 0.1 OThER*

O 0.0 0.2 0.1 Subtotal 2

2.8 3.4 3.5 3.9 4.2 POWER LESS THAN 15%

r EQUIPMENT FAILURE

• 0 0.3 0.4 0.3 0.4 0.3 DESIGN / INSTALLATION ERROR

• 0 0.0 i

OPERATING ERROR

• 0 0.2 0.1 0.2 0.1 0.3 MAlhTEhANCE ERROR

• 0 0.0 0.1 EXTERhAL*

0 0.0 CTHER*

0 0.0 0.1 Suttotal 0

0.5 0.7 0.5 0.5 0.6 i

TOTAL 2

3.3 4.1 4.0 4.4 4.8 1993 1992 1991 1990 1989 NO. OF WEEKLY WEEKLY WEEKLY WEEKLY WEEKLY scrap TWE SCRAMS AVE R AGE AVERAGE AVERAGE AVERAGE AVERAGE (YTD)

TOTAL AUTOMATIC SCRAMS 2

2.5 3.1 3.3 3.2 3.9 j

TOTAL MANUAL SCRAMS 0

0.9 1.0 0.7 1.2 0.9 10iALS MAY DIFFER BECAUSE OF ROUNDlWG OFF

• Detailed breakdown net in database for 1991 and earlier

- EXTERhAL cause included in EQ'JIPMENT FAILURE

- MAthTEhANCE ERROR and DESIGN /IkSTALLATION ERROR causes included in OPERATING ERROR

- OTHER cause included in EQUIPMENT FAILURE 1991 and 1990 ETS-14 Page: 1 10/22/93

.E 1

NOTES i

1.

PLANT SPECIFIC DATA BASED ON INITIAL REVIEW OF 50.72 REPORTS FOR THE WEEK OF INTEREST.

PERIOD IS MIDNIGHT SUNDAY THROUGH MIDNIGHT SUNDAY.

i SCRAM 3 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.

2.

PERSONELL RELATED PROBLEMS INCLUDE HUMAN' ERROR, PROCEDURAL DEFICIENCIES, l

AND MANUAL STEAM GENERATOR LEVEL CONTROL PROBLEMS.

l 3.

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

4.

"OTHER" INCLUDES AUTOMATIC SCRAMS ATTRIBUTED TO ENVIRONMENTAL CAUSES l

(LIGHTNING), SYSTEM DESIGN, OR UNKNOWN CAUSE.

J OEAB SCRAM DATA Manual and Automatic Scrams for 1987 ------------------ 435 Manual and Automatic Scrans for 1988 ------------------ 291 Manual and Automatic Scrams for 1989 ------------------ 252 Manual and Automatic Scrans for 1990 ------------------ 226 Manual and Automatic Scrams for 1991 ------------------ 206 Manual and Automatic Scrans for 1992 ------------------ 212 Manual and Automatic Scrams for 1993 --(YTD 10/17/93)-- 142 j

4

~

e j

^%

i

.CCI 2 8 1933 MEMORANDUM FOR:

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

Alfred E.

Chaffee, Chief Events Assessment Branch i

Division of Operating Reactor Support

SUBJECT:

OPERATING REACTORS EVENTS BRIEFING 1

OCTOBER 20, 1993 - BRIEFING 93-40 On October 20, 1993, we conducted an Operating Reactors Events Briefing (93-40) to inform senior managers from offices of the j

Chairman, ACRS, NRR, AEOD, OIP, EDO and regional offices of selected events that occurred since our last briefing on October 13, 1993. lists the attendees.

presents the significant elements of the discussed events. contains reactor scram statistics for the week ending October 17, 1993.

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

Origint siped W Alfred E.

Chaffee, Chief Events Assessment Branch Division of Operating Reactor Support

Enclosures:

As stated DISTRIBUTION:

Central Files cc w/ enclosures:

PDR i

See next page LKilgore, SECY EAB R/F KGray RDennig EGoodwin DSkeen EBenner TKoshy

)l0.

(m

/$

SE EAB/ DORS /

EAB/DORd dra/DO S f

EGoodwin AChaffee 10/

/93 10/2/, /93 10S[/93 OFFICIAL RECORD COPY DOCUMENT NAME:

ORTRANS.KAG (G:\\KAG)

e i

l,

-r i

l l=

cc:

T. Murley, NRR (12G18)

W. Huffman (AEOD) i F. Miraglia, NRR (12G18)

J. Giitter (AEOD)

F. Gillespie, NRR (12G18)

G. Edison (PDI-3)

J. Partlow, NRR (12G18)

W. Butler (PDI-3)

S. Varga, NRR (14E4)

J. Calvo, NRR (14A4)

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)

I 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) j S. Rubin, AEOD (MN-5219)

M.

Harper, AEOD (MN-9112) l G.

Grant, EDO (17G21)

I R. Newlin, GPA (2G5)

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

Bates, SECY (16G15)

T. Martin, Region I I

W.

Kane, Region I R.

Cooper, Region I S. Ebneter, Region II E.

Merschoff, Region II l

S.

Vias, Region II J. Martin, Region III i

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 i

~-.

,p* %,

3e

.7t

f*fE UNITED STATES Q,'j('g,, f NUCLEAR REGULATORY COMMISSION t

-J.-*

P WASHINGTON, D.C. 20555-0001 f

g[ t 819D t

MEMORANDUM FOR:

Brian K. Grimes, Director Division of Operating Reactor Support

[

FROM:

Alfred E. Chaffee, Chief l

Events Assessment Branch i

Division of Operating Reactor Support

SUBJECT:

OPERATING REACTORS EVENTS BRIEFING OCTOBER 20, 1993 - BRIEFING 93-40 l

l i

i on October 20, 1993, we conducted an Operating Reactors Events i

Briefing (93-40) to inform senior managers from offices of the

[

Chairman, ACRS, NRR, AEOD, OIP, EDO and regional offices of selected events that occurred since our last briefing on October 13, 1993. lists the attendees.

presents the significant elements of the discussed events. contains reactor scram statistics for the week ending

[

October 17, 1993.

No significant events were identified for i

input into the NRC Performance Indicator Program.

2+1

(' <

Alfred E.

Chaffee, Chief j

Events Assessment Branch Division of Operating Reactor Support

Enclosures:

As stated cc w/ enclosures:

See next page i

.]

l -

o I

r t

ENCLOSURE 1 l

LIST OF ATTENDEES OPERATING REACTORS EVENTS FULL BRIEFING (93-40)

OCTOBER 20, 1993 L

NAME OFFICE NAME OFFICE A. CHAFFEE NRR N. HUNEMULLER NRR T. KOSHY NRR E.

BENNER NRR K. GRAY NRR C.

GRIMES NRR M.

CULLINGFORD NRR J.

PARTLOW NRR C. MCCRACKEN NRR J.

CALLAN NRR G.

MARCUS NRR S.

VARGA NRR E. GOODWIN NRR W.

BUTLER NRR S. ROSENBERG NRR W.

HUFFMAN AEOD P. MADDEN NRR J. GIITTER AEOD A. PAL NRR H. ORNSTEIN AEOD C.

BERLINGER NRR G.

HOLAHAN AEOD R. IANDRY NRR J.

IBARRA OCM/IS E. THROM NRR J. MATHIS ACRS D.

SCALETTI NRR S.

MORRIS RI G.

EDISON NRR K. HENDERSON OIP T. YAMADA NRR L. PLISCO OEDO TELEPHONE ATTENDANCE (AT ROLL CALL)

Reaions Resident Inspectors Region I S. Greenlee (Beaver Valley)

Region III Region IV Region V IIT/AIT Team Leaders Misc.

NRC Technical Training Center

ENCLOSURE 2 l

i 4

i i

OPERATING REACTORS EVENTS BRIEFING 93-40 LOCATION:

10 B11, WHITE FLINT WEDNESDAY, OCTOBER 20, 1993, 11:00 A.M.

i FOREIGN REACTOR STATION BLACK 0UT

[ PROPRIETARY INFORMATION]

(UPDATE) i BEAVER VALLEY, UNIT 1 PLANT TRIP AND LOSS OF 0FFSITE POWER I

1 i

I PRESENTED BY:

EVENTS ASSESSMENT BRANCH DIVISION OF OPERATING REACTOR SUPPORT, NRR

- -, \\

93-40 BEAVER VALLEY, UNIT 1 PLART TRIP AND LOSS OF 0FFSITE POWER OCTOBER 12, 1993 PROBLEM UNIT 1 TRIP AND LOSS OF 0FFSITE POWER (LOOP) TO BOTH UNITS CAUSED BY SWITCHYARD MAINTENANCE.

UNIT 2 WAS SHUTDOWN AND DE-FUELED.

CAUSE INADEQUATE WORK CONTROL RESULTED IN SPURIOUS LOAD SHEDDING.

SAFETY SIGNIFICANCE UNANTICIPATED PLANT TRANSIENT AND CHALLENGES TO SAFETY SYSTEMS.

SEQUENCE OF EVENTS e

UNIT 1 WAS AT FULL POWER.

UNIT 2 WAS SHUT DOWN AND DE-FUELED.

A MAINTENANCE CREW WAS PERFORMING POST i

MAINTENANCE CHECKS ON AUXILIARY CONTACTS ON ONE OF TWO UNIT 2 MAIN OUTPUT BREAKERS (BK #352).

e THIS BREAKER WAS TAGGED OUT AT THE HIGH VOLTAGE SIDE BUT CONTROL POWER (DC) REMAINED AVAILABLE.

CONTACT:

T. K0 SHY, NRR/ DORS /0EAB AIT: 80

REFERENCE:

10 CFR 50.72 #26209 SIGEVENT: TBD

f BEAVER VALLEY, UNIT 1 2-93-40 l

WHILE CHECKING OUT UNIT 2 MAIN BREAKER AUXILIARY e

CONTACTS, THE MAINTENANCE CREW IMADVERTENTLY ACTUATED THE SUBSTATION UNDERFREQUENCY RELAYS.

THIS OCCURRED WHILE CHECKING AUXILIARY CONTACTS FOR l

e POSSIBLE MISALIGNMENT BY PLACING A LOW IMPEDANCE MULTIMETER, USING A CONTINUITY SCALE, ACROSS EACH OF 1

THE CONTACTS.

THE TECHNICIAN ESTABLISHED A PATH FOR 125 Voc POWER, THROUGH THE METER, TO THE SUBSTATION UNDERFREQUENCY TRIPPING RELAYS.

l e

THE UNDERFREQUENCY RELAYS RESPONDED PER DESIGN, TRIPPING OPEN TEN BREAKERS IN THE BEAVER VALLEY SUBSTATION AND CAUSING A 90% LOAD REDUCTION ON THE UNIT 1 MAIN GENERATOR AND ISOLATION FROM THE GRID.

THE UNIT 1 RESPONSE TO THE LOAD REDUCTION AND ISOLATION WAS A RAPID INCREASE IN TURBINE SPEED.

THE INCREASE IN MAIN GENERATOR OUTPUT FREQUENCY CAUSED THE REACTOR COOLANT PUMPS TO SPEED UP.

THIS CAUSED INCREASED REACTOR COOLANT FLOW AND A SUBSEQUENT REACTOR POWER EXCURSION.

THE REACTOR TRIPPED ON HIGH NEUTRON FLUX l

RATE.

i MILLISECONDS BEFORE THE REACTOR TRIP, THE TURBINE e

TRIPPED ON MECHANICAL OVERSPEED (110%).

THE TURBINE l

ELECTRICAL OVERSPEED TRIP ALSO FUNCTIONED WHEN THE i

TURBINE REACHED 111% SPEED.

4 n

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BEAVER VALLEY, UNIT 1 93-40 THE SUBSTATION LOAD SHEDDING AND THE UNIT 1 TRIP CAUSED i

e j

A L00? AT BOTH UN7TS.

e 0FFSITE POWER WAS RECOVERED AT BOTH UNITS WITHIN NINE MINUTES.

ALL SAFETY SYSTEMS AT UNIT 1 FUNCTIONED AS

}

DESIGNED.

UNIT 2 HAD ONE AVAILABLE EMERGENCY DIESEL i

i GENERATOR THAT STARTED AND SEGUENCED POWER TO NECESSARY l

SHUTDOWN LOADS.

PLANT RECOVERED FORCED CIRCULATION WITHIN APPR0XIMATELY e

j 10 MINUTES.

j DISCUSSION e

THE FUNCTION OF THE UNDERFREQUENCY RELAYS IS TO ISOLATE l

i DESIGNATED LOADS WHEN GRID FREQUENCY DROPS DUE TO l

I SYSTEM OVERLOAD.

THE INTENT WAS TO SHED EN0 UGH LOAD TO RESTORE GRID FREQUENCY AND THUS ALLOW THE BEAVER VALLEY 3

UNITS TO REMAIN ONLINE.

THE LICENSEE IS REEVALUATING THE DESIGN.

j e

THE LICENSEE MADE A FOUR HOUR REPORT TO THE OPERATIONS 1

CENTER BECAUSE OF THE REACTOR TRIP AND ENGINEERED l

SAFETY FEATilRE ACTUATION (EDG START).

I i

e THE LICENSEE'S EMERGENCY PLAN DID NOT REQUIRE 1

DECLARATION OF AN UNUSUAL EVENT (UE) FOR THIS j

OCCURRENCE.

THE LICENSEE IS NOW REEVALUATING THEIR i

CRITERIA FOR EMERGENCY CLASSIFICATIONS FOR A LOOP USING THE NUMARC GUIDANCE.

1 I

BEAVER VALLEY, UNIT 1 93-40 THE CONDITIONAL CORE DAMAGE PROBABILITY (CCDP) IS ESTIMATED TO BE 6E-05 ASSUMING PLANT CENTERED (SWITCHYARD INITIATED) LOOP, 2 HOUR BATTERY DEPLETION TIME, AND WESTINGHOUSE OLD REACTOR COOLANT PUMP 0-RING DESIGN.

DOMINANT ACCIDENT SEQUENCE IS LOOP WITH FAILURE OF EDGs e

AND SUBSEQUENT SEAL LOSS OF COOLANT ACCIDENT.

UNIT 1 IS IN COLD SHUTDOWN TO FIX A MINOR REACTOR COOLANT SYSTEM (RCS) LEAK IDENTIFIED FOLLOWING 4

SHUTDOWN.

A UE WAS DECLARED FOR THE RCS LEAKAGE.

FOLLOWUP REGION I IS MONITORING THE LICENSEE'S SHORT TERM AND LONG TERM ACTIONS.

I i

4

BRIEFING 93-40 BEAVER VALLEY, UNIT 1

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tutsetect eus ter tastaotect suo eat hTRIPPEDBREAKER rie e S-t ELECTRICAL INTERCONNECTIONS SWITCHYARD-POWER STATION SEAVtft VALLEY POWER STAfgDef (pet 880.1 IM)AftD FW8AL SAFETY AftALY94 furoset L

Ef? CLOSURE 3 REA: tor sCRA=

Reporting Feriod: 10/11/93 to 10/17/93 YTD YTD ABDVE BELOd YTD E

PLANT & Lik1T PMR g

g CCMPit:AT1045 TOTAL 10/12/93 EEAVER VALLEY 1 100 5A Maintename Error YES 1

0 1

1 10/h/c3 R;5ER EEhD 1 95 SA Eq.aipment failure ho 2

0 2

CESCEIFTIDh DF C &8i1 CAT 10 hts) 10/11/93 TO 10/17/93 g

yQT

[PPLICAT10k$

EE AVER h ALLEY 1

LOSS OF OFFSITE POWER CAttSED SCRAM AND LASTED 1.25 Ma>RS.

. g.

Arte: Tea-it Cate (YTC) Tctais In::voe Eve-ts Wittin Se Calenda" Tear Indicated By Tre End Cate Of The Specified Repeating Feriod ET5 10 p89':1 10/22/G3

COMFAR150N OF WEEKLY SCRAM STATISTICS WITH INDUSTRY AVERAGES PERIOD ENDING 10/17/93 N'JMBER 1993 1992 1991*

1990*

1929' 0F WEEKLY WEEKLY WEEKLY WEEKLY WEEKLY SCR&w CAUSE SCRAMS AVERAGE AVERAGE AVERAGE AVERAGE AVE R AGE (YTD)

POWER GREATER ThAh OR EQUAL TO 15%

EQUIPMEET FAILURE

• 1 1.8 2.6 2.9 3.4 3.1 CESIGN/ INSTALLATION ERROR

• O 0.0 OPERAT1kG ERROR

• 0 0.3 0.2 0.6 0.5 1.0 MAlhfEhAh:E ERROR

• 1 0.6 0.4 EXTER h AL*

O 0.1 CThER*

O 0.0 0.2 0.1 SAtetet 2

2.8 3.4 3.5 3.9 4.2 PJ.!ER LESS TMAh 15%

EQUIPMEhT FAILURE

• 0 0.3 0.4 0.3 0.4 0.3 CESIGh/!bSTALLAT!Dh ERROR

• O 0.0 OrERAT!hG ERROR

• 0 0.2 0.1 0.2 0.1 0.3 MAthTEhAh;E ERROR

• 0 0.0 0.1 EXTERhAL*

0 0.0 CTeER*

0 0.0 0.1 Ssbtetat 0

0.5 0.7 0.5 0.5 0.6 TCTAL 2

3.3

,1 4.0 4.4 4.8 1993 1992 1991 1990 1989 hD. OF WEEKLY WEEKLY WEEKLY WEEKLY WEEKLY S088" TvrE 50 RAMS AVERAGE AVE R AGE AVERAGE AVERAGE AVERAGE (YTD)

TCTAL AUT 7.ATIC SCRAMS 2

2.5 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 SECAJSE OF ROUND!bG OFF

• Detailed breakdann act in ciatabase for 1991 and earlier

- EXTE8hAL cause incluoed in EQUIPMEh1 FAILURE

- MAlkTEkan;E ERROR and DESIGh/IEST ALL ATIOh ERROR causes included in OF'ERATING ERROR

- CTPER casse inctuced in EQUIPMENT FAILUEE 1991 and 1993 l

i E'0- 4 Fage: 1 10/22/93

.)

u NOTES 1.

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 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.

2.

PERSONELL RELATED PROBLEMS INCLUDE HUMAN ERROR, PROCEDURAL DEFICIENCIES, AND !UiNUAL 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 Scrans for 1993 --(YTD 10/17/93)-- 142