ML20029D627
| ML20029D627 | |
| Person / Time | |
|---|---|
| Site: | Millstone, Arkansas Nuclear, Maine Yankee |
| Issue date: | 04/22/1994 |
| From: | Chaffee A Office of Nuclear Reactor Regulation |
| To: | Grimes B Office of Nuclear Reactor Regulation |
| References | |
| OREM-94-014, OREM-94-14, NUDOCS 9405090072 | |
| Download: ML20029D627 (21) | |
Text
-
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.o April 22, 1994 MEMORANDUM FOR:
Brian K.
Grimes, Director Division of Operating 97cctor Support 1
FROM:
Alfred E.
Chaffee, Chief Events Assessment Branch l
Division of Operating Reactor Support
SUBJECT:
OPERATING REACTORS EVENTS BRIEFING l
APRIL 20, 1994 - BRIEFING 94-14 On April 20, 1994, we conducted an Operating Reactors Events Briefing (94-14) to inform senior managers from offices of the 1
Commission, AEOD, EDO, ACRS, NRR, and regional offices of selected events that occurred since our last briefing on 1
April 13, 1994. lists the attendees.
presents the significant elements of the discussed events.
d j contains reactor scram statistics for the week ending l
April 17, 1994.
No significant events were identified for input i
into the NRC Performance Indicator Program.
ORIGINAL SIGNED BY:
Alfred E.
Chaffee, Chief Events Assessment Branch Division of Operating Reactor Support
Enclosures:
As stated l
cc w/ enclosures:
i See next page i
DISTRIBUTION:
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9405090072 940422 1
PDR ORG NRRB
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l cc:
W.
Russell, NRR (12G18)
G. Kalman (PDIV-1)
F. Miraglia, NRR (12G18)
W. Beckner (PDIV-1) i F.
Gillespie, NRR (12G18)
G.
Vissing (PDI-4)
Acting ADPR, NRR (12G18)
J. Stolz (PDI-4) l S.
Varga, NRR (14E4)
E. Trottier (PDI-3)
J.
Calvo, NRR (14A4)
W. Butler (PDI-3)
)
G.
Lainas, NRR (14H3)
L. Smith (Arkansas SRI) 1 J. Roe, NRR (13E4)
J.
Zwolinski, NRR (13H24)
E. Adensam, NRR (13E4)
A. Thadani, NRR (12G18)
B.
Sheron, NRR (7D26)
M. Virgilio, 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) i S.
Rubin, AEOD (MN-5219)
M.
Harper, AEOD (MN-9112) i W.
Bateman, EDO (17G21)
F.
Ingram, PA (2G5)
E.
A.
Bates, SECY (16G15)
T. Martin, Region I R.
Cooper, Region I S.
Ebneter, Region II J. Johnson, Region II S. Vias, Region II J. Martin, Region III E. Greenman, Region III L.
Callan, Region IV A. Beach, Region IV K. Perkins, Region IV/WCFO l
bec:
Mr. Sam Newton, Manager Events Analysis Department Institute of Nuclear Power Operations 700 Galleria Parkway i
j Atlanta, GA 30339-5957 i
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NUCLEAR REGULATORY COMMISSION l,
WASHING' UN, D.C. 20566-0001
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'2, 1994 l
MEMORANDUM FOR:
Brian K.
Grimes, Director Division of Operating Reactor Support l
FROM:
Alfred E.
Chaffee, Chief l
Events Assessment Branch l
Division of Operating Reactor Support
SUBJECT:
OPERATING REACTORS EVENTS BRIEFING APRIL 20, 1994 - BRIEFING 94-14 On April 20, 1994, we conducted an Operating Reactors Events Briefing (94-14) to inform senior managers from offices of the Commission, AEOD, EDO, ACRS, NRR, and regional offices of selected events that occurred since our last briefing on April 13, 1994. lists the attendees.
presents the significant elements of the discussed events. contains reactor scram statistics for the week ending l
April 17, 1994.
No significant events were identified for input l
into the NRC Performance Indicator Program.
l h
l Alfred E.
Chaffee, Chief i
Events Assessment Branch Division of Operating Reactor Support l
Enclosures:
As stated l
cc w/ enclosures:
See next page
ENCLOSURE 1 l
LIST OF ATTENDEES i
OPERATING REACTORS EVENTS FULL BRIEFING (94-14)
APRIL 20, 1994 l
NAME OFFICE NAME OFFICE A.
CHAFFEE NRR E.
MARINOS NRR T.
KOSHY NRR C.
BERLINGER NRR
)
K.
GRAY NRR L.
REYES NRR l
E. GOODWIN NRR C.
ROSSI NRR l
B.
GRIMES NRR M.
CULLINGFORD NRR l
T.
YAMADA NRR T.
ALEXION NRR S.
ALEXANDER NRR E.
BAKER OCM/IS l
L. NORRHOLM NRR J.
TATUM OEDO l
S. MITRA NRR A. RUBIN OEDO K.
NAIDU NRR V.
BENAROYA AEOD G.
KALMAN NRR G.
HOLAHAN AEOD J
L.
LOIS NRR D.
COE ACRS S. MAZUMDAR NRR TELEPHONE ATTENDANCE (AT ROLL CALL)
Recions Resident Inspectors Region I J. Melfi (Arkansas 1)
Region II D. Lew (Maine Yankee)
Region IV l
l IIT/AIT Team Leaders Misc.
l l
r
ENCLOSURE 2 i
)
OPERATING REACTORS EVENTS BRIEFING 94-14 i
i LOCATION:
10 Bil, WHITE FLINT l
WEDNESDAY, APRIL 20, 1994 11:00 A.M.
i 1
j ARKANSAS NUCLEAR,So-30 PLANT TRIP FROM LIGHTNING UNIT 1 i
i l
MILLSTONE, UNIT 2 snuC MAGNE-BLAST. BREAKER FAILURE MAINE YANKEE so.pg TO LATCH CLOSED i
i i
i i
i i
PRESENTED BY:
EVENTS ASSESSMENT BRANCH DIVISION OF OPERATING REACTOR j
SUPPORT, NRR
~
i
94-14 ARKANSAS NUCLEAR, UNIT 1 l
PLANT TRIP FROM LIGHTNING APRIL 11, 1994 PROBLEM:
PLANT TRANSIENT AND TRIP DUE TO LIGHTNING.
l CAUSE:
l LIGHTNING INDUCED EMERGENCY FEEDWATER ACTUATION.
SAFETY SIGNIFICANCE:
l UNANTICIPATED CHALLENGES TO PLANT AND OPERATORS FROM i
SAFETY GRADE POWER SUPPLY FAILURES.
l EVENT DETAILS:
i o
AT 8:41 P.M. THE OPERATORS OBSERVED MAIN STEAM l
ISOLATION VALVES G0ING CLOSED.
l o
THE INCREASE IN REACTOR COOLANT SYSTEM (RCS) PRESSURE i
TO APPR0X. 2350 PSI. GENERATED AN AUTOMATIC REACTOR l
TRIP FROM "A" & "C" CHANNELS. THE CONTROL ROOM OPERATOR ALMOST SIMULTANE0USLY INSERTED A MANUAL REACTOR TRIP.
o EMERGENCY FEEDWATER (EFW) PUMP "A" STARTED BUT THE AUTOMATIC LEVEL CONTROL FAILED.
o EFW PUMP "B" STARTED AND MODULATED THE FLOW TO THE j
STEAM GENERATORS (SG).
i l
CONTACT:
THOMAS K0 SHY, NRR/ DORS /0EAB AIT:
NO
REFERENCE:
10 CFR 50.72 #27077 SIGEVENT: TBD i
i
ij-ARKANSAS NUCLEAR, UNIT 1 94-14
{
o PRESSURE LEVEL INDICATIONS FROM EFW CHANNEL B & D WERE l
LOST.
j i
i o
ATMOSPHERIC DUMP VALVE (ADV)
"A" AND ASSOCIATED BLOCK i
VALVE CYCLED OPEN AS DESIGNED AND THEN CLOSED AS SG i
PRESSURE DROPPED BY THE OPENING OF THE CODE SAFETY VALVES.
i l
o ADV "B" FAILED OPEN.
APPROXIMATELY FOUR MINUTES INTO THE EVENT THE OPERATOR OPENED THE ASSOCIATED BLOCK i
VALVE SINCE IT DID NOT AUTO OPEN.
ADV "B" DID NOT CLOSE WHEN THE PRESSURE DECREASED BELOW SETPOINT CAUSING EXCESSIVE C00LDOWN.
o PRESSURIZER LEVEL DROPPED BELOW RANGE FOR APPROX. FOUR MINUTES.
o AT 8:45PM STARTED HIGH PRESSURE INJECTION (HPI) PUMP TO REC 0VER PRESSURIZER LEVEL.
l o
LOSS OF THE B & D POWER SUPPLY FOR EMERGENCY FEEDWATER l
INITIATION AND CONTROL (EFIC) CHANNELS CAUSED RCS l
C00LDOWN.
i j
o THE PRESSURIZER PRESSURE DROPPED TO 1700 PSI.
(SI ACTUATION IS AT 1526 PSI) i o
AT 8:46PM OPFRATOR MANUALLY ACTUATED TRAIN "B" EFW T0 ENABLE TRAIN "B" MAIN FEEDWATER ISOLATION.
i i
o AT 8:48PM SECURED HPI FLOW TO RCS.
l i
i e
t i-ARKANSAS NUCLEAR, UNIT 1 94-14 i
l o
BOTH ADV BLOCK VALVES WERE FIRST CLOSED TO MITIGATE THE l
C00LDOWN.
ADV "A" DID NOT OPEN FROM CONTROL ROOM AFTER l
INITIAL OPENING.
AT 9:27PM IT WAS THEN JACKED OPEN AND THE ADV BLOCK VALVES WERE OPENED MANUALLY AS NEEDED TO CONTROL RCS TEMPERATURE.
o STEAM GENERATOR LEVELS DROPPED TO A MINIMUM OF 30 INCHES IN "A" & "B".
DISCUS _SIDH:
o THE LICENSEE BELIEVES THAT THE LIGHTNING IN THE
!l IMMED7 ATE PR0XIMITY OF CONTAINMENT BUILDING PENE' 4 A ',0NS INDUCED A VOLTAGE SPIKE ON CABLE SHIELuidG.
i THIS INDUCED VOLTAGE REACHED THE SIGNAL COMMON AT THE o
"B" & "D" POWER SUPPLIES FOR EFIC SYSTEM.
o THE R:REASED VOLTAGES CAUSED THE 15 VDC POWER SUPPLY OVERVOLTAGE PROTECTIVE CIRCUITRY TO SHUTDOWN THE POWER SUPPLIES AND DEENERGIZE CHANNELS "B" & "D".
l o
EFW ACTUATED AS EXPECTED FROM THE RESULTING POWER FAILURE.
(FULL ACTUATION ON TRAIN "A" AND HALF ACTUATION ON TRAIN "B")
i e
EFW PUMP "A" FAILED TO CONTROL LEVEL DUE TO LOSS OF CONTROL POWER.
EFW PUMP "B" DELIVERED FULL FLOW.
4 e
ADV "B" FAILED OPEN FROM A LOSS OF THE EFIC POWER.
THE BLOCK VALVE WAS MANUALLY OPEH2D TO REDUCE SG PRESSURE.
(BLOCK VALVE DID NOT AUTO OPEN DUE TO LOSS OF POWER) s
j.
ARKANSAS NUCLEAR, UNIT 1 94-14 i
o ADV "A" BLOCK VALVE OPENED DUE TO TRAIN "A" MAIN STEAM l
LINE ISOLATION.
(THE LICENSEE GENERALLY OPERATES WITH j
THE DOWN STREAM BLOCK VALVE CLOSED.
THIS IS A NON l
SAFETY SYSTEM.)
ADV "A" BLOCK VALVE WAS USED TO CONTROL SG PRESSURE o
j AFTER IT WAS BLOCKED OPEN.
THE PROBLEM WITH ADV "A" l
WAS CAUSED BY IMPROPER ADJUSTMENT OF THE AIR PRESSURE i
REGULATOR AND SOME VALVE DEGRADATION.
i o
TECHNICAL SPECIFICATION (TS) C00LDOWN RATE WAS NOT EXCEEDED (MAXIMUM C00LDOWN WAS 39*F.
TS LIMIT IS 50*F l
IN HALF HOUR).
o 46/62 FUSES BLEW IN THE "B" TRAIN OF INADEQUATE CORE COOLING MONITORING AND DISPLAY SYSTEM (ICCMDS).
THESE ARE 5 MA. FUSES.
i o
LICENSEE'S TROUBLE SHOOTING NARROWED THE FAILURES T0 CABLES ASSOCIATED WITH TWO PENETRATIONS.
)
o LICENSEE CONDUCTED PHYSICAL INSPECTIONS AND i
SURVEILLANCES TO VERIFY THE INTEGRITY OF POTENTIALLY VULNERABLE SYSTEMS.
i I
CERTAIN SURVEILLANCES THAT REQUIRE PLANT AT POWER e
OPERATIONAL STATUS WERE CONDUCTED DURING POWER ASCENSION.
FOLLOWUP:
o NRR AND REGIONAL STAFF CONDUCTED TWO CONFERENCE CALLS WITH THE LICENSEE TO ASSESS THE EVENT AND REVIEW CORRECTIVE ACTIONS.
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94-14 MAINE YANKEE i
MAGNE-BLAST BREAKER FAILURE TO LATCH CLOSED MARCH 23, 1994 PROBLEM i
HIGH PRESSURE SAFETY INJECTION (HPSI) PUMP BREAKER WOULD l
NOT LATCH CLOSED.
OTHER SIMILAR BREAKERS AT MAINE YANKEE l
(MY) AND MILLSTONE (MP) HAVE EXPERIENCED THE PROBLEM.
i l
CAUSE l
PR0XIMATE CAUSE OF LATCHING FAILURE WAS INADEQUATE PROP 4
ACTION IN THE BREAKER CLOSING MECHANISM.
INADEQUATE PROP ACTION CAUSED BY RECENT GENERAL ELECTRIC
}
(GE) REPLACEMENT OF ORIGINAL TUF-LOC PROP BUSHINGS WITH ALUMINUM-BRONZE PROP BUSHINGS.
i SAFETY SIGNIFICANCE j
POTENTIALLY IN0PERABLE 4160-VAC SAFETY-RELATED BREAKERS:
}
E.G.,
EMERGENCY CORE COOLING, CONTAINMENT SPRAY, EMERGENCY l
DIESEL GENERATOR OUTPUTS, VITAL 4160-VAC BUS SUPPLIES AND TIES, COULD LEAD TO COMMON MODE FAILURE OF MULTIPLE SAFETY j
SYSTEMS.
]
BACKGROUND MAGNE-BLAST BREAKER MANUFACTURER, GE SPECIALTY BREAKER o
l PLANT (SBP), ISSUED SERVICE ADVICE LETTER (SAL) 318.1-IN FEBRUARY 1977, " REPLACEMENT OF TUF-LOC SLEEVE
{
BEARINGS WITH ALUMINUM-BRONZE SLEEVE BEARINGS ON SELECTED RATINGS OF MAGNE-BLAST BREAKERS" BECAUSE OF l
UNACCEPTABLE WEAR PATTERNS ON SOME TUF-LOC SLEEVE l
BEARINGS [ BUSHINGS]
l 1
CONTACT:
S. ALEXANDER, NRR/DRIL/VIB AIT:
NQ i
REFERENCE:
VIB IR 99901001/94-01 SIGEVENT: TBD l
l-1 l'
MAINE YANKEE 94-14 REPLACEMENT BUSHING KIT DID NOT CONTAIN PROP BUSHINGS CALLED FOR RELUBRICATING WITH THE D50H15 " WHITE" j
i GREASE (MECHANICAL PARTS ONLY)
PROP BUSHINGS ONLY BEING REPLACED RECENTLY I
l o
GE SBP ISSUED SAL 348.1, DECEMBER 1990, " PROP SPRINGS, i
ML-13, ML-13A MECHANISMS, ALL 5KV, 7.2KV AND 13.8KV j
TYPE AM AND VVC BREAKERS" DEALT WITH PROBLEMS OF MAIN PROP SPRING FAILURE MENTIONED 2-PROP SPRING CONFIGURATION, BUT DID NOT l
RECOMMEND ADDITION OF SECOND PROP SPRING WHERE ONLY j
A SINGLE ONE WAS INSTALLED i
l D_ISCUSSION o
PROBLEM DISCOVERED DURING POST OVERHAUL TESTING AT l
i MILLSTONE AND DURING TESTING FOR LIMIT SWITCH PROBLEM i
AT MAINE YANKEE.
i l
o GE SBP AND GE NUCLEAR ENERGY HAVE CONDUCTED FAILURE j
ANALYSIS INSPECTION AND TESTING (0BSERVED BY LICENSEE i
AND NRC) AND ARE EVALUATING THE ISSUE FOR MY, MP AND l
SCOPE OF PRODUCT SUSCEPTIBILITY.
SUBSEQUENT DISASSEMBLY AND DETAILED PARTS EXAMINATION WERE OBSERVED BY MY AND YANKEE NUCLEAR SERVICES DIVISION.
COMBINATION OF FACTORS MUST EXIST FOR A BREAKER TO BE PRESENTLY CONSIDERED SUSCEPTIBLE:
[
(1) POTENTIALLY AFFECTED MODELS i
ALL AM-4.16-350 SERIES l
AM-4.16-250-6, -7,
-8,
-9HB
MAINE YANKEE 94-14 (2) 0F THESE MODELS, ONLY THOSE EQUIPPED WITH ONE y
l PROP SPRING (IN PRODUCTION WITH TWO SINCE 1969) j (3) 0F THE 1-PROP SPRING BREAKERS OF THE j
POTENTIALLY AFFECTED MODELS, ONLY THOSE IN i
WHICH THE PROP BUSHINGS (IN ADDITION TO ALL THE i
OTHERS) HAVE BEEN REPLACED WITH ALUMINUM BRONZE HAVE EXPERIENCED, OR ARE EXPECTED TO EXPERIENCE l
THIS MODE OF LATCHING FAILURE.
i o
MY HAS MOVED ITS 10 2-PROP SPRING MAGNE-BLASTS INTO I
MOST CRITICAL POSITIONS (REQUIRING CLOSING RELIABILITY FOR DESIGN BASIS EVENT -(DBE)), SOME OF THE 14. WITH ONE PROP SPRING MAY ALSO HAVE TO BE ABLE TO CLOSE RELIABLY IN A DBE.
MY IS EVALUATING THEIR CONTINUED l
MY T0-PERFORM SPECIAL INSPECTIONS WITH GE l
TO IDENTIFY ANY BREAKERS FOR WHICH OPERABILITY MAY BE l
DOUBTFUL.
i FOLLOW UP j
e MY WILL BE ADDING SECOND PROP SPRING TO REST OF j
o RESIDENT INSPECTORS, REGION, AND NRR ARE FOLLOWING ISSUE CLOSELY.
l o
VENDOR AND ELECTRICAL BRANCH VISITED MY TO EXAMINE j
BREAKER LATCHING FAILURES AND LIMIT SWITCH PROBLEMS.
i SITE VISIT FOLLOWED BY INSPECTION AT GE APPARATUS SERVICE SHOP IN PHILADELPHIA TO OBSERVE EXAMINATION AND l
FAILURE ANALYSIS TESTING OF ONE OF MY's AFFECTED l
BREAKERS.
i l
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j' 1;'
MAINE YANKEE 94-14
}
i o
VENDOR BRANCH PREPARING INFORMATION NOTICE.
i o
VENDOR BRANCH WILL BE INSPECTING GE NUCLEAR ENERGY (SAN I
JOSE) WEEK OF APRIL 25-29.
3 4
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... -., _... - _. _ _ _.... _. ~,. _ _ _....... _.. _.....
1 BRIEFING 94-14 MAGNE-BLAST OPERATING MECHANISM PROP O!AGRAM
'1 e.
-l
/5
~
1.
Handle 2
2 Trip Coil Suppri
'.I
[A 3.
Trip Coil 3
/? <
4.
Trip Armature L /;//
c..,~
5.
Prop Spring
/ '..r.
SA. Second Prop Spring T.' g /-
?
A (if fitted)
..gg_;j 9
6.
Cam Follower Roller C-
_. _ :. l.'.
C..,..._.r 7.
Trip Shaft 7
~
gj 5
8.
Trip Latch Q
./
[M 9.
Trip Latch Roller
/
'i
- 10. Roller Support
} ~c
. Cr s
i k
-d
- '7k
~8 Pro Pin e
i U -
hb
- 15. Drive Shaft
{Q/
- 16. Cam t.
w. % p u h m.
g' 1
/
r' FotvARP Qgsk figure 1 (Adapted From Figure 7 of GE Instruction Book gel-88761)
M(All-1
- 09 91N t
N.
x me J
', :'.V # '
Wi@
J Are ion of inspection hole
^-
E_
through which prop position
. I age can be viewed
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Figure 2: Right Side View of ML-13 Operating Mechanism (f rom Figure 4 of GE Instruction Book gel-88761) m-.
~. - -
1 BRIEFING 94-14 Scre MI.13 sectanisns used an GI vartical lift breakers manufme = red in Philadelphia aftar 1968 with close and latch ratings of 77kA er 78kA have an additional spring, above and in parallel with the lover prop spr_.g as sacvn in Figure 2.
Both springs are illustrated in in -. :cc books GZZ-7320 and GZZ-7347 in Figure 7 Itans 12 and 14 fer these tjpes of breakers.
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There have been repc.~ s of string failures (Cat. No.
0137A9211P001) Uniet have resulted in tne inabilitf of the breeAer te
,re=ain clesed.
These reper s indiezza that failures have occurred on broaXers hav:.nq exceeded 2000 operatiens.
The springs which failed vore of tae earlies: design (riq=re 3A) which was in production
{
batveen 1963 and 1971.
Since 1971, a spring with modified ends as chcun in figure 3B bas been used.
Infrequan; failures in industr:.a1 (non-nuclear) applicaticns have oc=urred with these anwer type springs
- Lth E=dLIL *d *=ds
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t f 4 uke 3 A t
FIGatE 36 5
In 1990, the prep spring was redesigned to be interchangeable with both varia::.cns.
The new spring (cat. No. 0275A7211P001) has certain changes in tae manuf ac~aring and finishing operations for the purpcse of inpreving the f atigue strancth of the spring.
The new spr:ng has been teseec satt sf acterily ;,.n a life test of 10,000 cperations.
It is rec __ =- f-d ttzt all nuclear safet/ related or critical breakers be i..spected as seen as possible to caeck that thaDp opring is still f u..c icning.
It is recc=cended that replacament springs be cMered, and during scheduled maintenance, the prop spring be replaced.
tnis is espec:. ally critical on breaxars approaching 2000 Dec.t.=ulative operaticns.
~
f Ro n.A S A L.F 33'. l A
ENCLOSURE 3 REACTOR SCRAM i
Reporting Period: 04/11/94 to 04/17/94 l
1 i
YID YTD ABOVE BELOW YTD E
PLANT & UNIT POWE R M
CAUSE COMPLICATIONS M
TOTAL l
04/11/94 AREANSAS WUCLEAR 1 100 SM External YES 1
0 1
l 04/11/94 NINE MILE PolN1 1 0
SA Equipment Failure NO 1
1 2
04/15/94 BROWNS FERRY 2 100 SA operating Error No 1
0 1
04/15/94 MONilCELLO 1 100 SA External NO 1
0 1
1 DESCRIPfl0N OF COMPLICAfl0N(S) 04/11/94 10 04/17/94 E
UE COMPLICATIONS ASKANSAS NUCLEAR 1
OVERC00 LING TRANSIENT DUE TO FW CONTROL AND ATMOSPHERIC DUMP VALVE PROBLEMS.
Veer To Date (YTC) Totals include Events Within The Caterdar Year Indicated By the Erd Date of The Specified Reporting Period dote:
's-10 Page:1 04/18/94
- i
i COMPARISON OF WEEKLY SCRAM STAT!STICS WITH INDUSTRY AVERAGES PERIOD ENDING 04/17/94 NUMBER 1994 1993 1992 1991*
1990*
OF WEEKLY WEEKLY WEEKLY WEEKLY WEEKLY j
SCRAM CAUSE SCRAMS AVERAGE AVERAGE AVERAGE AVERACE AVERAGE (YTD)
POWER GREATER THAN OR EQUAL TO 15%
f EQUIPMENT FAILURE
- O 1.70 1.83 2.62 2.88 3.38 j
DESIGN / INST ALLATION ERROR
- 0 0.00 0.04 l
OPERATING ERROR
- 1 0.20 0.27 0.23 0.58 0.48 MAINTENANCE ERROR
- 0 0.39 0.52 0.40 EXTERNAL
- 2 0.13 0.13 OTHER*
0 0.00 0.02 0.23 Subtotal 3
2.42 2.81 3.48 3.46 3.86 l
POWER LESS THAN 15%
EQUIPMENT FAILURE
- 1 0.20 0.38 0.40 0.29 0.40 DES!CN/lNSTALLATION ERROR
- 0 0.07 OPERATING ERROR
- 0 0.13 0.13 0.13 0.15 0.08 MAINTENANCE ERROR
- 0 0.00 0.02 0.06 EXTERNAL
- 0 0.00 0.04 OTHER*
0 0.00 0.06 Subtotal 1
0.40 0.57 0.65 0.44 0.48 TOTAL 4
2.82 3.38 4.13 3.90 4.34 1994 1993 1992 1991 1990 No OF WEEKLY WEEKLY WEEKLY WEEKLY WEEKLY SCRAM TYPE SCRAMS AVERAGE AVERAGE AVERAGE AVERAGE AVERACE (VTD)
TOTAL AUTOMATIC SCRAMS 3
2.16 2.44 3.06 3.25 3.21 TOTAL MANUAL SCRAMS 1
0.65 0.94 1.02 0.65 1.19 TOTALS MAY DIFFER BECAUSE OF ROUkDING OFF
- Detailed breakdown not in database for 1991 and earlier
- EXTERNAL cause included in EQUlPMENT FAILURE
- MAINTENANCE ERROR and DESIGN / INSTALLATION ERROR causes included in CPERATINC ERROR
- OTHER cause included in EQUlPMENT FAILURE 1991 and 1990
.15 14 Page: 1 04/18/94
NOTES i
e 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.
j 2.
PERSONNEL 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 Scrams for 1988 ------------------ 291 Manual and Automatic Scrams 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 175 Manual and Automatic Scrams for 1994 --(YTD 04/17/94)-- 43
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