ML20043F172

LER 90-009-00:on 900510,RWCU Outboard Suction Isolation Valve 2G33-F004 Auto Closed Which Tripped RWCU Pump B. Caused by Procedure Deficiency.Procedure LTS-500-209 Will Be revised.W/900605 Ltr

ML20043F172
Person / Time
Site:	LaSalle
Issue date:	06/05/1990
From:	Dierich G, Sampson P COMMONWEALTH EDISON CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-90-009-02, LER-90-9-2, NUDOCS 9006140220
Download: ML20043F172 (5)

Text

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• [ 'N Commonwealth Edloon LaSalle County Nucimr Station

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c)7 Marseilles,i:linois61341

' Rural Reute #1, Box 220  :

Telephone 815/357-6761 l-June 5, 1990 Director of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Mail Station F1-137 Washington, D.C. 20555

Dear Sir:

Licensee Event Report #90-009-00, Docket 9050-374 is being

, submitted to your office in accordance with 10CFR50.73 -

(a)(2)(iv).

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l O. J. Diederich l Station Manager LaSalle County Station GJD/PSS/1s Enclosure .

xc Nuclear Licensing Administrator -

NRC Resident Inspector NRC Region III Administrator INPO - Records Center t

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DRoo614o22o 900603 ',

g ADOCK 05000374 /

PDC ,

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LICENSEE EVEN1 REPORT (LER) F 2.0 fac)11ty.Name (1) Docket thsuber (2) Pese (3) i LaSalle County Station Unit 2 01 51 01 01 01 31 71 4 1lof!0l4 14tle (4)

Anactor 16ater Clean up Puno irld Due to a Procedural Deficiency durina Surveillance Testine Event Date (5) t1R thauber (6) Report Date (7) Other Facilities involved (8)

Facility Names Docket thsiber(s)

Month Day Year Year /4/ Sequential /,/,/, Revision Month Day Year W/ thsiber W/ thesber 01 51 01 01 of I I of5 110 91 0 91 0

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01019

~

010 016 01 5 91 0 01 51 01 01 01 I I THIS REPORT IS $UBMiliED PURSUM110 THE REQUIREMENTS OF 10CFR OPERATING (Check one or more of the followinn) (11)

I'I

_,, 20.402(b) 20.405(c) _X__ 50.73(a)(2)(iv) ,,, 73.7)(b)

POWER , 20.40$(a)(1)(l) 50.36(c)(1) 50.73(a)(2)(v) ,_ 73.71(c)

LEVEL 20.405(a)(1)(ll) 50.36(c)(2) 50.73(a)(2)(vil) _

Other (Specify 0! 0! 0 (10) ,__. 20.40$(a)(1)(111) _, 50.73(a)(2)(l) 50.73(a)(2)(vill)(A) in Abstract

// // /// //////,/,/, _ 20.40$(a)(1)(lv) 50.73(a)(2)(ll) , 50.73(a)(2)(vill)(8) below and in f

/ / / / / ///,/f/ ,_, 20.405(a)(1)(v) ,_,,,, 50.73(a)(2)(lli) __ 50.73(a)(2)(x) 1 ext) ff LICENStE CONI ACT FOR THIS LER (12) 1ELEPIIONE NUpBER Hame AREA CODE Paul Mson. Technical Staff Ennineer. Ext. 2704 8 1 1 15 315171-l6171611 COWLETE ONE tlNE FOR F.ACH C090NENT F AILURE DESCR18FD IN THl$ REPORT (13)

CAUSE SYSTEM COMPONENT MNUFAC- REPORTABLE CAUSE SYSTEM COMPONENT MMUFAC- REPOR1ABLE /

TURER TO NPRDS TURER 10 MPRDS 0 CIE I I I I I I N I I I I I I I I I I I I I I I I I I I I I SUPPLDUTAL REPORT EXPECTED (14) Expected Month l Day l Year SubalssIon lyes (if ves. complete EXPECTED SLSM15510N DATE) YlNO l ll ll ABSTRACT (Limit to 1400 spaces, i.e, approximately fifteen single-space typewritten lines) (16)

On May 10, 1990 at approximately 0534 hours0.00618 days <br />0.148 hours <br />8.829365e-4 weeks <br />2.03187e-4 months <br />, with LaSalle Unit 2 defueled, while returning to their nonnal line ups following the perfonnance of LaSalle Technical Staff Surveillance L15-500-209 " Unit 2 Division 1 Emergency Core Cooling Systems Response ilme Test', the Unit 2 Reactor Water Cleanup (RT) Outboard Suction isolation Valve 2G33-F004 auto closed, which in turn tripped the '8" RT Pump.

After valve 2G33-F004 closed, the control room reactor operator identified a Group 5 Primary Containment isolation Signal (PCIS) present, reset the isolation signal, re-opened valve 2G33-F004, and re-started the

'8* RT punp.

The cause of this event is a procedure deficiency. L15-500-209 does not address that the Group 5 isolation signal would occur, and does not address the resetting of the isolation logic pelor to restoring equipment to their nonnal lineups.

L15-500-209 will be revised to lor.lude a precaution that a Group 5 isolation signal will be initiated when bus 241Y ls deenergized. A step will also be added to the procedure to reset the Group 5 isolation signal prior to returning eq'ilpment to nonnal lineups.

This event is eportaSle to the NRC pursuant to the requirements of 10CFR50.73(a)(2)(lv) due to the actuation of an Englneered Safety Feature Systse.

l

A tlCENSEE EVENT REPORT (liR) TEH1 COWileRIA11(BI Fors Rev 2.0 ,

DOCKEI NUISER (2) LER 1RpeER (6) Pome (3)

FACill1Y teAME (1)

Year 5equential / Revision

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f

// lieber // linduer LaSalle County Station, Unit 2 015101010131114 910 - 01019 - 01 0 01 2 0F 01 4 1 EXT Energy industry identification System (Ells) codes are identified in the text as [xx]

PLANT AND SYSTEM IDENTIFICAll0N General Electric - Dolling Water Reactor Energy Industry Identification System (Ell 5) codes are identified in the text as [xx].

A. CONDli10N PRIOR TO EVENT unit (s): 2 Event Date: $/10/90 Event lime: 0534 Hours Reactor Mode (s): ,1., Mode (s)Nme: Defueled PowerLevel(s): 0 B. DESCRIPil0N OF EVENT On May 10, 1990 at approximately 0534 hout 5, with LaSalle Unit 2 defueled, while returnir.3 equipment to their norinal line ups following the performnce of LaSalle Technical Staff Surveillance L15-506 e09

' Unit 2 Division 1 inergency Core cooling lystem (Er,CS) Response Tier lest", the Unit 2 Reactor idater Cleanup (RT) (CE] Outboard Section isolatlio Valve 2G334004 closed automatically, which in turn tripped the "B" R1 Pump. The closing of valve 2G3's-F004 is an Engineered Safety Feature Actuation.

L15-500-209 deenergizes Unit 2 electrical Olvison 1 bus 241Y and other busses fed from 241Y in conjunctionwithamanualLossofCoolantAccident(LDCA)tignaltoverifythe*0'DieselGenerator(OG)

(EK) (00001K) auto starts and picks up its corresponding faergency Core Cooling System loads within a specified time ll! nit. Valve 2G33-F004 receives a Group 5 isolation signal from the Primary Contalnment isolation Systens (PCis) (JM). The Group 5 signal ws due to the loss of power to RT fliter/demin high inlet temperature switch (non45F function) 2G33-N008 which is powered from MCC 235x-1. MCC 235X-1 is powered from bus 241Y. 2G3341008 falls to the tripped condition on loss of power. Valve 2G334004 is interlocked such that if closed, the "B" R1 pump will trip to protect the pop (loss of suction flow path). Prior to deenergizing bus 241Y in accordance with L15-500 209, the 2G334004 valve circuit breaker was opened, and a lead ws lifted from the temperature sulich to prevent a trip of the "B" RT pop. L15-500-209 provides the option of taking these steps to prevent tripping tb '8" RT pop if the pump is running. This option is made available if the "B" RT pep is desired for maintaining reactor vessel wier clarity. When bus 241Y ms deenergized per L15-500-209, a Group 5 isolation sigac1 was received as designed (valve 2G334004 ms prevented from closing), however, the isolation was not identified or reset prior to reclosing the 2G33-f004 valve circuit breaker. This caused the 2G334004 valve to go closed, which in turn tripped the "B" RT pump.

After valve 2G334004 closed and the "B" RT pop tripped, the control room reactor operator identified the Group 5 Isolation signal was present, reset the isolation signal, re-opened valve 2G33-F004, and re-started the "B" RT pap.

This event is reportable pursuant to the requirements of 10CFR50.13(a)(2)(lv) due to the actuation of an Engineered Safety Feature System .

. 1 2

LICENSEE EVENT REPORT (Lit) TEIT CONTINUATION Fo m hee 2.0 FAClltif NAE (1) 00CKET NueER (2) LER NU SER (6) Pane (3)

Year / Sequential /j/j/ hevision

/j//j/

f

/ Weber f

/// thaber LaSalle County Station onit 2 0 1 5 1 0 1 0 l o 1 31 71 4 910 - 010l9 - 01 0 01 3 0F 01 4 I 1 EXT Energy Industry identification System (Ells) codes are identified in the text as [KX]

l C. APPARENT CAUSE OF EVENT The cause of this event is a procedure deficiency. L15-500-209 does not address that the Group 5 isolation signal would occur, (although it did identify that valve 2G334004 would close unless action was taken), and does not address the resetting of the Group 5 isolation logic prior to re-closing the 2G334004 valve circuit breaker. This probism has not occurred in the past due to the control room operators identifying the Isolation signal, and resetting it prior to reclosing the the 2G334004 valve circuit breaker. The step in the procedure to open the circuit breaker is not always perfomed (optional based on plant condition), and L15-500-209 states that the '8" RT pug will trip if this step j is not perfomed. l A contributing cause is that opersting personnel did not fully evaluate an off normal Indication and take prompt action to resolve it. Previously a Group 5 signal was identified as being present due to a back panel indicating light. Ite logic was reset but the cause was not detemined. The cause was a previous test which deenergized bus 241Y. If the cause of this signal had been detemined, it could have prevented this isolation. I i

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D. SAFETY ANALYSIS OF EVENT The safety consequences of this event were minimal. At the time of the event, Unit 2 was shutdown and I defueled. The RT and PCIS systems functioned as designed. In addition, LTS-500-209 is only performed during refuel outages.

E. CORRECTIVE ACT10NS After valve 2G334004 closed and the "B" RT pop tripped, the control room reactor operator identified the Group 51sclation signal present, reset the isolation signal, re-opened valve 2G334004, and re-started the 'B" RT pop.

L15-500-209 will be revised to include a precaution that a Gmup 5 Isolation signal will be initiated when bus 241Y is deenergized. A step will also be added to the procedure to reset the Group 5 isolation signal prior to re-closing the 2G334004 valve circuit breaker. Due to the potential of this problem occurring on electrical Divisions I and 2 on both units 1 and 2 during surveillance, the following additional procedures will also be reviewed. (LTS-500-109 ' Unit 1 Olvison 1 ECCS Response ilme", i L15-800-104 *lA Diesel Generator 24 Hour Run lest", L15-800-105 '2A Diesel Generator 24 Mar Run Test"). Action lism Record (AIR) 374-200-90-03601 has been initiated to track completion of this review. There is however, no corresponding RT high filter /desin inlet tenperature switch on Olvision 11 due to it Mla a non-ESF function. AIR 374-200-90-03101 has also been initiated to track tallgating of Operating License holders evaluating off nomal indications, and to provide additional direction when testing equipment which affects isolation logic. AIR 374-200-90-03302 has been initiated to review operating procedures and abnonnals associated with deenergizing ESF busses te determine if any changes are required.

LICENSEE EVENT REPOR1 (LER) 1 EXT CONTINuAll0N Fom hev 2.0 DOCKET MuleER (2) LER tapeER (6) Pane (3)

FAcIll14 NAME (1)

Year /g/

f ,

Sequential ///

f Revision

/// lp&er /T/ thsiber oISIoIoIo 1 31 71 4 9 Lp - ofole - ofo el 4 0F of 4 Lasa11e countv Station unit 2 1EKI Energy industry Identification System (Ells) codes are identified in the text as [XXJ F. PREVIOUS EVEN15 LER lhster iltle 373/64-049 40 Secondary Containment isolation During lesting 373/97-009-00 Group 4 1 solation During Survel11ance Test Due to Instrument Maintenance Procedure ludequacy 374/90-007-C0 Partial Group 21 solation During Reactor Protection System Bus Transfer due to inadequate Procedure and out of Service G. COMPONENT IAlLURE DATA Manufacturer Womenclature Model Number MFG Part theuber None

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