ML20205H752
| ML20205H752 | |
| Person / Time | |
|---|---|
| Site: | Braidwood, Surry, Diablo Canyon, Cook, Rancho Seco, 05000000 |
| Issue date: | 10/18/1988 |
| From: | Jaudon J Office of Nuclear Reactor Regulation |
| To: | Rossi C Office of Nuclear Reactor Regulation |
| References | |
| OREM-88-041, OREM-88-41, NUDOCS 8810310165 | |
| Download: ML20205H752 (20) | |
Text
-
,g 007 2 8 268 MEMORANDUM Fbn:
Charles E. Rossi, Director Division of Operational Events Assessment FROM:
Johns P. Jaudon, Acting Chief Events Assessment Branch Division of Operational Events Assessment
SUBJECT:
THE OPERATlhG REACTORS EVENTS HEETING October 18, 1988 - HEETING 88 41 On October 16, 1988, an Operating Reactors Events meeting (88 41) was held to brief senior managers from NRR. OSP, AE00, RES, Commission Staff, and Regional Offices on events which occurred since our last meeting on October 11, 1988.
The list cf attendees is included as Enclosure 1.
The events discussed and the significant elements of these event.s are presented in Enclosure 2. presents a summary of reactor scrams.
No significant events were identified for input to NRC's performance indicator program.
Johns P. Jaudon, Acting Chief Events Assessment Branch Division of Operational Events Assessment
Enclosures:
As stated cc w/ Encl.:
See Next Page OlSTRibOT10N Central f1 R f
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T. Murley, 12G-18 C. Pate). 14H-22 F. Miraglia, 12G-18 H. Berkow. 24H-22 J.'$niezek. 12G-16 S. Sands 130-1 E. Jordan. AEOD D. Muller, 130-1 J. Taylor, 17G-13 G. Kalman 13E-16 E. Beckjord NL-007 G. Knighton, 13E-16 W. Russell, RI W. Scott, 13H-15 J. N. Grace. Ri!
T. Quay. 13H-15 B. Davis Rill H. Rood. 13E-16 R. D. Martin. RIV J. B. Martin RV W. Kane, R1 L. Reyes, Rll i
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L. Callen RIV D. Kirsch. RV S. Varga. 14E.4 D. Crutchfield. 13A-1 B. Boger. 14A-2 G. Laines. 14H-Z G. Holahan 13H-4 L. Shao. 8E-2 J. Partlow 70-24 B. Grimes 9A-2 F. Congel, 10E-4 E. heiss. AEOD T. Martin EDO J. Guttmann. SECY A. Thadant. 7E 4
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Oc; I a m MEMORANDUM FOR:
Charles E. Rossi. Director Division of Operational Events Assessment FROM:
Johns P. Jaudon. Acting Chief Events Assessment Branch Division of Operational Events Assessment
SUBJECT:
THE OPERMlhG REACTORS EVENTS MEETlhG October 18, 1988 - MEETING 88-41 On October 18. 1983, an Operating Reactors Event: meeting (88-41) was held to brief senior ranagers f rom NRR. OSP, AE00. RES, Comission Staf f, and Regional Offices on events which occurred since our last meeting on October 11, 1988.
The list of attendees is included at Enclosure 1.
t The events discussed and the significant eierents of these events are presented in Enclosure 2. presents a sumary of reactor scrams.
No significant events were identified for input to hRC's performance indicator program.
4l$44*
t Johns P Ja don, Act ng Chift Events Assisstent Branch f
Division o Operational Events Assessment
Enclosures:
As stated cc w/ Encl.:
See hext Page i
s I
ENCLOSURE 1 l
LIST OF ATTEh0EES OPERATING REACTORS EVENTS BRIEFING (88-41) f October 18, 1988 NAME ORGANIZATION NAME ORGANIZATION T! Rurley Likih=
RT Iccleston hRR/DRPI-2 D. Crutchfield NRR/00EA P. Baranowsky NRR/00EA B. Boger NRR/ADR-1 G. Lainas NRR/ADR-2 J. Jauden NRR/00EA C. Schulten NPR/00EA i
C. Patel NRR/0RP M.L. Reardon NRR/DOEA
- 5. Juergens SECY E. Rossi NRR/00EA i
W. Minr.ers RES/0RPS J. Norrholm OCM/KC R. Kendal)
NRR/00EA T.P. Gwynn OCM/LZ C. McCracken NRR/ DEST J. Stefano P03-1 J. Dyer NRR/ DEST M. Virgilio hRR/0RSP
[
- v. Benarcye AE00/OSP J. Donohew, Jr.
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B. Siegel NRR/P03-2 L.B. Engle NRR/P02 2 S. Sands NRR/P03-2 F. Miraglia hRR/A9T J. Zwolinski NRR/DLPQ J. Roe NRR/DLPQ J. Clifford DECR0 i
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ENCLOSURE 2 OPERATIflG REACTORS EVENTS BRIEFING 88-41 EVENTS ASSESSMEf1T BRANCH LOCATIOS2 12-B-11 WHITE FLINT
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IDESDAY, OCTOBER 18, 1988, 11:00 A.M.
SURRY UNIT 1 SPEhT FUEL POOL GA1E SEAL FAILURE BRAIDh00D UNIT 1 LOSS OF 0FFSITE POWER AND REACTOR TRIP j
i '
RAkCHO SECO REACTOR TRIP ON LOSS OF FORCED CIRCULATION COOLING D.C. COOK UhlTS 1 8 2 BROKEN RETAltdR BLOCK STUDS ON ANCHOR AND DARLING check VALVES DIABLO CANYON UNIT 2
88-41 SURRY UNIT 1 SEEDT FUEL P00L GATE SEAL FAILURE OCTOBER 2, 1988 2BBLEb POTENTIAL FOR LOSS OF SPENT FUEL P0OL (SFP) IfiVEN10RY DURING DRY TESTlfiG OF FUEL TRANSFER SYSTEM.
EBSE POTEN11AL FAILURE OF AIR SUPPLY TO SFP TRAliSFER CANAL GATE SEAL.
SAFETY SIGNIFICANCE o
IfiCREASED RADIATION LEVELS IN SFP BUILDifiG.
o POTEfiTI AL INJURY AND CONTAMINATION OF PERSONNEL DISCUSSI0h o
PLAliT SHUTDOWN - DRY TESTING OF.'UEL TRAllSFER SYSTEM IN PROGRESS PRIOR TO FUEL OFF-LOAD.
o SFP TRAf1SFER CAliAL GATE CLOSED - SEAL lhFLATED.
o Plfi HOLE LEAK IN AIR SUPPLY LINE TO SEAL PROMPTLY STOPPED BY OPERATOR.
o NO DEFLATI0fl UF SEAL AND NO SFP WATER LOSS, o
REVIEW 0F EVENT REVEALS POTENTIAL FOR SEAL FAILURE AND LOSS OF SFP lhVENTORY THROUGH FUEL TRANSFER TUBE, FUEL TRANSFER CANAL lliSIDE CONTAINMEliT AND DOWri REACTOR CAVITY.
o TRANSFER TUBE GATE VALVE CLOSURE MAY NOT BE POSSIBLE UNDER CERTAIN COND1110!iS.
o CURRENT REFUELING PROCEDURES DO NOT REQUIRE THE REACTOR CAVITY SEAL ASSEMBLY TO BE IN PLACE PRIOR TO DRY TESTING 0F FUEL TRANSFER SYSTEM.
o WORST CASE SCEf4AR10 WOULD DRAlli SFP TO 13" AB0VE TOP 0F FUEL ASSEMBLIES.
SINULTANE0US FUEL TRAf4SFER AllD DRY TESTlfiG OF FUEL TRANSFER SYSTEM NOT CREDIBLE.
C0fiTACT:
D. CUDINOT
REFERENCES:
MORN 1f4G REPORT 10/07/88
SURRY UNIT 1 88-41 o
LICENSEE ESTIMATES THAT THE DOSE RATE, BASED ON SFP INVENTORY AT TIME OF EVENT, COULD REACH 50R/ HOUR.
O RALIAT10h LEVELS WOULD LIMIT STAY TIME IN SFP BUILLiNG AND COULD DELAY CORRECTIVE ACTIONS.
FOLLOWUF o
LICENSEE DESIGN REVIEW REC 0KMENDS THAT DRY TESTING PROCEDURE BE hEVISED TO RECUlRE THE REACTOR CAVITY SEAL ASSEMBLY TO BE INSTALLED PRIOR TO DRY TESTING OF FUEL TRANSFER SYSTEM.
o REGION 11 IS FOLLOWING UP, o
EVENTS ASSESSMENT bkANCH IS CONSIDERING ISSUANCE OF AN INFORMATION h0TICE.
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88-41 BRAICWOOD UNIT 1 LOSS OF 0FFSITE POWER AND REACTOR TRIP OCTOBER 16, 1988 PEDBLEB TOTAL LOSS OF CFFSITE POWER AND REACTOR TRIP.
EbDSL FAILURE OF CIRCUlT BREAKER TO OPERATE PROPERLY AND CARDBOARD IN A REACTOR COOLANT PUMP TIME DELAY /0VERCURRENT RELAY.
$1EETY SIGNIFICANCE LOSS OF PREFEFRED POWER SUPPLY.
DlSLDSSlDB o
ON OCTOBER 16, 19EC, A FAULT WHICH OCCURRED ON THE DAVIS CREEK LINE INTO THE BRAIDWCOD 345KV SUBSTATION RESULTED IN A LOSS OF THE OFFSITE POWER TO UNIT 1.
c CB 7-11 AND CL 7-8 OPENED AS PER DESIGN.
HOWEVER, CB 4-7 DID NOT FULLY OPEN (POLE DISAGREEMENT).
o CB 3-4 SENSED THE MISOPERATION OF CB 4-7 AND OPENED
- THEREBY, SEPARATING THE UNIT FROM THE SYSTEM AUX TRANSFORMER, o
A RAPID AUTO TRANSFER FROM THE SYSTEM AUX TRANSFORMER TO THE UNIT AUX TRANSFORMER TOOK PLACE AS PER DESIGN, HOWEVER: THE TIME DELAY /0VEf; CURRENT f,ELAY ON THE IC RCP FAILED TO OPERATE PROPERLY CAUSING THE PUMP TO TRIP FROM THE UNIT AUX BUS, o
LICENSEE FOUND CARDBOARD IN THE RELAY WHICH PREVENTED PROPER RELAY OPERATION.
o THE REACTOR TRIPPED FROM 9G% POWER ON LOW REACTOR COOLANT FLOW.
o ALL ESF SYSTEhS RESPONDED AS PER DESIGN.
o REACTOR REMAINED IN NATURAL CIRCULATION FOR 2 HOURS AND 25 MINUTES WHILE THE SYSTEM LOAD DISPATCHER EVALUATED THE DAVIS CREEK FAULT AND DETERMINED IT WAS SAFE TO RESTORE OFFSITE POWER.
CONTACT:
N. FIELDS
REFERENCE:
50.72 # 13734
BRAIDh'00D UNIT 1 88-41 EDLLQhDE o
LICENSEE !!;VESTIGATIfiG THE ORIGili 0F CARDBOARD IN THE TIME DELAY /
OVERCURRENT RELAY.
o LICEllSEE IS If4VESTIGATlhG THE CAUSE OF POLE DISAGREEMENT ON CB 4-7,
AMENDMENT 47 APRIL 1986 5
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5 BR AIDWOOD STATION FIN AL S AFETY AN ALYSIS REPORT FIGURE 8.2-5 345-kV SWITCHYARD BUS ARRANGEMENT
l 88-41 RANCHO SEC0 REACI E JElf_0N LOSS CF FORCED CIRCULATION COOLING OCTOBER 14, 1988 EEDEES A REAtlCR TRIP, TURBihE TRIP Afit MAIN GENERATOR TRIP FROM 91% POWER OCCURREE /FTER 2 0F THE 4 REACTOR COOLANT PUMFS (RCPs) TRIPPED BECAUSE OF A VOLTAGE PilASE IMBALANCE ON THE ONSITE ELECTRICAL DISTRIBUTION SYSTEM.
THE RENAlfilh6 2 RCPs TRIPPED 1 SECOND LATER.
l
.CESE THE VOLTAGE PHASE IMBILANCE RESULTED FROM ECUIPMENT FAILURE OFFSITE (GCE 2:2 AT THE STAGG SUBSTATION) AND A SUBSEQUENT FAULT OFFSITE (BETWEEf: THE TESLI. ANL STAGG SUBSTATIONS) THAT WAS NOT ISOLATED FROM RANCHO SECC EY THE EXISTING PROTECTIVE RELAYING SCHEME (SEE FIGURE 1).
SAFETY SIGhlFICANCE
- 1. LOSS OF FORCED CIRCULAT10h C00Lil1G REQUIRES OPERATORS TO ESTABLISH 1
NATURAL CIRCULATION COOLING (IllCLUDES PROPER CONTROL OF AUXILI ARY FEEDWATER BY Tl;E EMERGEtiCY FEELWATER INITI ATION AND CONTROL, EFIC, SYSTEM).
THE OPERATORS SUCESSFULLY ACHIEVED CONTROLLED HEAT REMOVAL VI A IUiTURAL CIRCULATION, THE PLANT REMAINED WITHIN THE B&WOG A10G "POST TRIP WINDOW" (1.E., A Kh0kli SAFE STATE AS DEFil4EL BY Tite EhERGENCY OPERATil10 PROCEDURES: SEE FIGURE 2).
- 2. INABILITY TO CLEAR OFFSITE FAULTS TO PREVEllT DEGRADATI0fi 0F THE l
OliSITE POWER DISTRIBUTION SYSTEM CAft RESULT Ifi Ufit;ECESSARY CHALLEf1GES TO PLAliT EQUlFhEliT AND TO SAFETY SYSTEhS (E.G., EMERGEliCY DIESEL l
GENERATORS).
i i
BJSCUSSION o
NORTHERN AND CEliTRAL CAllFORNIA EXPERIENCING HEAVY AUTUMN RAINS.
i o
0400 - PHASE-TO-GROUNL FAULT OCCURRED AT LOCAT10ti #1 OCBs 282, 222, f
240, ANL 340 TRIPPED OPEN TO ISOLATE THE FAULT.
i 0
0430 - PG&E RECLOSED OCB 282 AT TESLA IkDEPENDENTLY, SMUD TRANSFERREL RCP BUS GE TO UNIT AUXILIARY TRANSFORMER N0. 1 BY PROCEDURE.
1 C0hTACT:
R. KENDALL
REFERENCE:
50.72s # 13709, 13726 ANC MORNIf;G REPORT 10/17/SE
RANCHO SECC 88-41 0
0515 - PGEE RECLOSED OCB 222 AT STAGG (THE TRIP C0ll FOR OCB 222 IS BURNEC OUT UNKNOWN TO PG8E).
o 0530 - SMUD RECLOSES OCBs 240 AND 340 AT REQUEST OF LOAD DISPATCHER, o
0C14 - A 3-PHASE UNBALANCED FAULT OCCURRED AT LOCATION #2.
THE FAULT IS SENSED AT STAGG BY ITS PROTECTIVE RELAYlNG CIRCulTRY WHICH SENDS A "CARRIER SIGNAL" BACK TO RANCHO SEC0 FOR OCBs 240 AND 340 TO REMAIN CLOSED.
SINCE OCB 222 WAS FAILED AND THE RANCHO SECO FAULT PROTECTION FOR THIS TYPE OF FAULT ONLY EXTENDS TO ZONE 1, RANCHO SECO FED THE FAULT FOR 31 SECONDS.
o RCPs "B" AND "D" TRIPPED ON A PHASE IMBALANCE SIGNAL; RPS INITIATED REACTOR TRIP CN POWER-10-FLOWS TURBINE-GENERATOR TRIP OCCURS (CCBS 220 AND 230 TRIP OPEN)
RCPs "A" AND "C" TRIPPED ON A PHASE IMBALANCE SIGNAL; AUTOMATIC FAST TRANSFER FROM UNIT AUXILIARY TRANSFORMER NO. 1 TO STARTUP TRANSFORMER N0. 1 0CCURS: EFIC SYSTEM AUTOMATICALLY INITIATES AND CONTROLS AUXILil.RY FEEDWATER TO THE NATURAL CIRCULATIUN SETPOINT.
0 0742 - RCP 'D" RESTARTED.
0 0830 - REMAINING 3 RCPs HAVE BEEN RESTARTED.
o 0842 - BEGIN SWITCHOVER FROM AUXILIARY FEEDWATER TO MAIN FEEDWATER (COMPLETED AT 0904).
IDERECTIVE ACTIONS
- 1. SMUD HAS EXTENDED PHASE-TO-PHASE FAULT PROTECTION TO ZONE 2 TO PREVENT RECUkRENCE (20 CPS /40 CPS TinikG SCHEME BETWEEN OCB 222 AND OCEs 240 AND 340).
SITUATION IS UNIQUE TO STAGG.
- 2. SMUD INVESTICATION OF SENSITIVITY OF RCP TRIP CIRCUITRY (THE RCPs WERE THE ONLY EQUIPMENT 10 RESPOND TO DEGRADED ONSITE VOLTAGE).
- 3. SMUD EVALUATION OF ADE0VACY OF PROTECTIVE RELAYING SCHEMES FOR ALL INC0hlNG DISTRIBUTION LINES TO THE RANCHO SECO SWITCHYARD (SUSCEPT-IBILITY TO SINGLE FAULTS).
ECLLDEUE REGION V IS MONITORING LICENSEE ACTIONS: EAB WILL REY!EW THE LICENSEES FINAL ANALYSIS OF THE EVEhT WHEN C0hPLETE.
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88-41 4
D.C. COOK UNITS 1 a 2 AND DIABLO_ CANYON UNIT 2 SE0 KEN RETAINER BLOCK STUDS Off ANCHOR DARLIt1G CHECK VALVES SEPTEMBER 9 AND OC10BER 10, 1988 fR0BLEM FAILURE OF THE RETAINING BLOCK STUDS HOLDING DOWN THE CLAPPER ARM ON ANCHOR DARLlh6 CHECK VALVES.
fAllSE POSSIBLE CORROSION PROLLEM WITH B0 RATED WATER CAUSING IGSCC ON ASTM A193 GRADE B6 TYFE 410 ST AINLESS STEEL WITH A HIGH HARDNESS RATING (GREATER THAft 26-28 ROCKWELL "C" HARDNESS RATING),
SAFETY SIGNIFICANLE GENERIC IMPLICATIONS COULD EXTEND TO OTHER SAFETY-RELATED VALVES AND VENDORS IF 410 stall 1LESS (WITH AN ABNORMAL HIGH HARDNESS RATING) IS USED IN B0 RATED WATER SYSTEMS, allC1LSSl.0li o
Oh SEPTEMBER 9 ANL OCTOBER 10, 1988 RESPECTIVELY, D.C. COOK 1 AND 2 AND DI ABLO CANYON UtilT 2 IDENTIFIED RETAINING BLOCK STUD FAILURES Oh CHECK VALVES IN THE RHR AhD S1 If4 JECT 10N SYSTEMS.
o DIABLO CANYON Uhl1 i HAD TWO BROKEN STUDS ON ONE RHR INJECTION CHECK VALVE (TWO SlVDS/ CHECK VALVE); D.C. COOK HAD A TOTAL OF FOUR BROKEN AND FIVE CRACKED STUDS ON CHECK VALVES IN THE RHR AND SI SYSTEMS.
o THE VALVE VENDOR (ANCHOR DARLING) HAD CHANGED FROM USING 410 STAINLESS STEEL TO TYPE 17-4PH STAINLESS STEEL FOR VALVES KNOWN TO BE USED Ik BORATED WATER SYSTEMS (1981 TIME FRAME).
o WITH SERIOUSLY DEGRADED STUDS, THE RETAINING BLOCKS COULD BE DISLODGED IF THE VALVES ARE CALLED UPON TO OPEN RAPIDLY DURlhG ACCIDENT CONDITIONS.
o NEITHER OF THESE CONDIT10flS WERE REPORTED BY A 50.72.
CONTACT:
J. THOMPSCN
REFERENCE:
RESILENT PHONE CALL FROM DIABLO CANYON UNIT 2
D.C COOK UNITS 1 & 2 AfiD 88-41 DIABLO CANYON UNIT 2 o
IN 88-85, "BROKEN RETAIN!f1G BLOCK STUDS ON Af1CHOR DARLING CHECK VALVES", ISSUED Oli 10/14/88.
FOLLOWbt FURTHER EFFORTS ARE NEEEED TO DETERMINE IF THIS PROBLEM EXISTS OUTSIDE OF AliCHOR DARL! fig.
MECHANICAL ENGINEERING AND MATERIALS ENGINEERING BRANCHES ARE LETERMlfilNG IF FURTHER GENERIC ACTION IS WARRANTED.
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