05000315/LER-1985-040, :on 850807,RHR Low Flow Alarm Bypassed When Alternate Flow Path Used.Caused by Failure to Monitor Flow Indicators After Low Flow Alarm Installation.Controls Implemented Requiring Operators to Monitor Alternate Path

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:on 850807,RHR Low Flow Alarm Bypassed When Alternate Flow Path Used.Caused by Failure to Monitor Flow Indicators After Low Flow Alarm Installation.Controls Implemented Requiring Operators to Monitor Alternate Path
ML20135D975
Person / Time
Site: Cook American Electric Power icon.png
Issue date: 09/06/1985
From: Blind A
INDIANA MICHIGAN POWER CO. (FORMERLY INDIANA & MICHIG
To:
Shared Package
ML20135D918 List:
References
LER-85-040, LER-85-40, NUDOCS 8509160244
Download: ML20135D975 (2)
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LER-1985-040, on 850807,RHR Low Flow Alarm Bypassed When Alternate Flow Path Used.Caused by Failure to Monitor Flow Indicators After Low Flow Alarm Installation.Controls Implemented Requiring Operators to Monitor Alternate Path
Event date:
Report date:
3151985040R00 - NRC Website
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text

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LICENSEE EVENT REPORT (LER)

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THIS IS A SPECIAL REPOFE CONCERIING A CONDITION DISCOVERED DURING TIE INVESTIGATION OF TifE EVHE REPORTED IN LER 50-315/85-031.

ON AUGUST 7,1985, AT 1800 HOURS WIDI BOlli UNITS 1 AND 2 IN l'0DE 5 (COID SHUIDOhW), IT WAS DLTERMINED 'IIIAT DE RESIDUAL HEAT REbMAL (RHR) IW-FION AIAIN IS BYPASSED h11Di AN ALTERNATE (ECCS) FION PATH IS USED. THE IG-FIM ALARM WAS INSTALLED IN THE NORMAL COOLDOWN PEIURN LINE 'IO SATISFY A UNIT 2 LICENSE CONDITIW.

THIS LICENSE CWDITIW, h1IICli NAS IMPOSED DUE 'IO CONCERN OVER INADVERTDE ISOIATION VALVE CIOSURE, REQUIRED THAT TIE FIN INDICNIORS BE cot 11'INUOUSLY 110NI'IORED DURING RHR OPERATION. UPON INSTALIATION OF DIE RHR IM-FION AIARM, MIE LICENSE CONDITION WAS RENOVED. HCHEVER, 'I1E OOCASIWAL USE OF AN ALTERNATE FIN PADI, WIIICH HAS NO ION-FION AIABM, HAS RESULTED IN THE SI'IUNITJN 'I11AT PRmPTED THE ORIGINAL Ll'JENSE CONDITION.

'IO INSURE THAT A IDSS OF RHR FION IS Dt:1u;1w, APPROPRIATE CORROLS HAVE BEEF IMPLDEVI'ED REGJIRING THE COtEROL ROOM OPERA'IORS 'IO lDNI'IOR RHR FION INSTRUMDEATION h1IEN USING THE ALTERNATE FIOW PATH.

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"^a D.C. COOK NUCLEAR PLANT, UNIT 1 0 l5 l0 l0 l0 l3 l 1l5 815 0l 4l 0 0[ 0 0l2 OF 0l2 TEXT t# more space a requae4 vse smooner AAC Form J66A sJ (171 HIIS IS A SPECIAL REPORT CONCERNING A CONDITION DISCOVERED DURING TIE INVESTIGATICN OF 71IE EVH7f REPORTED IN LER 50-315/85-031.

ON AUGUST 7,1985, AT 1800 HOURS WITH BUTH UNITS 1 AND 2 IN MODE 5 (COID SHU11XhN), IT WAS DETERMINED THAT THE RESIDUAL HEAT REMOVAL (RHR) IG-FIN AII@M IS BYPASSED MIEN AN ALTERNATE (ECCS) FIM PATH IS USED. TIE IN-FLOW AIARM WAS INSTALLED IN THE NORMAL COOLDOhN REIURN LINE TO SATISFY A UNIT 2 LICENSE CCNDITION.

DIIS LICENSE CONDITION, hEICH h%S IMPOSED DUE TO CONCERN OVER INADVErEa7f ISOLATION VALVE CIDSURE, REQUIRED 711AT THE FIN INDICATORS BE CONTINUOUSLY FONITORED DURING RHR OPERATION. UION INSTALLATION OF THE RHR IM-FIM ALARM, 71E LICENSE CWDITIW WAS RDINED. HOWEVER, TIE OCCASICNAL USE OF AN ALTERNATE FIN PATE, MIICH HAS NO IG-FIM AIARM, HAS RESULTED IN DE SITUATION THAT PROMPTED TIE ORIGINAL LICDISE CONDITICN.

INADVERTENT CIOSURE OF THE RER ISCIATICN VALVES IS NOT CONSIDERED TO BE A LIKELY EVENT. ONCE THE VALVES HAVE BEEN OPENED, POWER IS RDKNED FROM TIE VALVE OPERATORS. THUS,11E RESTORATICN OF PCMER 'IO TIE VALVES IS A PREREQUISITE TO CIOSURE OF TIE VALVES.

MIEN THE ALTERNATE FIN PAHI IS USED, TIE INDICATIONS AVAIIABLE 70 HIE OPERATOR 'IO KMPN OF A IM-FIN OWDITICN ARE:

1.

PUMP ABNORMAL OR IOCKOUT AIARM 2.

PGMP FDIOR INSTANT TRIP ALARM 3.

FIN FffERS (NO ALARM) 4.

PUMP AbEETER (NO AIARM)

ANY OF 11IESE COUID ALERP THE OPERATOR TO THE IOSS OF RHR FIM. TIE LOSS OF RHR FIM HAS BEEN EVAIEATED, AND UNDER DIE WORST ASSUMED CONDITICNS,100 MINU'rES ARE AVAIIABIE BEFORE DE CORE MXJID BECCFE UNCOVERED. THUS, IT IS JUDGED HIAT 711ERE c

WAS TIME FOR THE OPERA 7OR TO DLTECT THAT A PROBLD1 EXISTED AND TAKE ACTION TO RESTORE RHR COOLING.

BASED ON TIE FACTS THAT THERE IS INSTRUMalTATION hEICII NOUID ALIN 'I1IE OPERATOR TO DETECT A IOSS OF RHR FIN AND 711AT THERE WOUID BE TIME TO RES7 ORE RHR COOLING, IT IS CONSIDERED THAT THIS CONDITIW DID NOT CONSTITUTE AN UNREVIEWED SAFEIY QUESTICN AS DEFINED IN 10 CFR 50.59 NOR DOES IT ADVERSELY AFFECT TIE PUBLIC HEALTII AND SAFEIY.

TO INSURE 711AT A IDSS OF RHR FIN IS Dt;m;m), APPROPRIATE CONTROLS HAVE BEEN IMPLWENTED REQUIRING HIE C0tTEROL ROOM OPEPATORS TO MONITOR RHR ETm INSTRUMENTATION hEEN USING THE ALTERNATE FIN PATH.

N20 FORw 366A IS $33

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