ML19332F243

LER 89-025-00:on 891101,sys Auxiliary Transformer Feed to Bus 142Y Tripped Open When Equipment Operator Closed Door Containing Relays.Caused by Misalignment of Door.Isolations Reset,Bus Energized & Circuit Logic tested.W/891201 Ltr

ML19332F243
Person / Time
Site:	LaSalle
Issue date:	12/01/1989
From:	Bukantis L, Diederich G COMMONWEALTH EDISON CO.
To:	Office of Nuclear Reactor Regulation
References
LER-89-025-01, LER-89-25-1, NUDOCS 8912140129
Download: ML19332F243 (4)

Text

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l [N ' CommonweeNh LaSalle County Nuclear Edloon Station

( ) RuralRoute #1, Box 220 i \ -_'" Marseilles, Illinois 61341 4 Telephone 815/357 6761 '

i I

l December 1, 1989 Director of Nuclear Reactor Regulation  ;

'U.S. Nuclear Regulatory Commission  ;

. Mail Station P1-137 Washington, D.C. 20555

Dear sir:

f Licensee Event Report #89-025-00, Docket #050-373 is being submitted to your office in accordance with 10CFR50.73(a)(2)(iv). -j i /

O. J. Diederich h(StationManager LaSalle county Station GJD/ LAB /kg Rnclosure  ;

l xc: Nuclear Licensing Administretc,r NRC Resident Inspector NRC Region III Administrator INPO - Records Center y i Ij 8912140129 891201 ePDR. ADOCK. 05000373 PDC s ,

l LICENSEE EVENT REPORT (LER) g Docket Noter (2) Paee (3)

Tacility Name (1) tA 4 11e County Station Unit 1 01 bl 01 01 01 31 71 3 1loFl0 3 Title (4) I Less of bus 142Y Oue to Closina $witchaear Door and Jarrina Relays )

Event Date (5), LER thster (6) M et Date (7) Other facilities involved (0)

Sequential ev s on Month Day Year Facility Names ' Docket Noter (s) i Month Day Year Year ,//j

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Lasalle Unit 2 of $1 01 01 of 31 71 4 el 9 el 9

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01215

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01 0 112 of I el 9 01 51 01 01 of I i 11 1 01 1 TH15 REPORT 15 $UBMITIED PURSUANT TO THE REQUIREMENi$ OF 10CFR (Check one or more of ttu followina) (11)

" $ 20.402(b) ,,,,,, 20.405(c) ,X_,50.73(a)(2)(lv) _ 73.7)(b) 20.405(a)(1)(1) 50.36(c)(1) .,_, 50.73(a)(2)(v) ,_,_ 73.71(c)

POWER _,,,,,,

Other ($pecify LEVEL 20.405(a)(1)(ll) ,,__ 50.36(c)(2) ,,__ 50.73(a)(2)(vil) _

i 0;1 in Abstract (10) 01 0 20.405(a)(1)(lli) ,,,,,_ 50.73(a)(2)(1) ,,,,,_ 50.73(a)(2)(vill)(A) 20.405(a)(1)(lv) 50.73(a)(2)(ll) 50.73(a)(2)(vill)(B) below and In

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50.73(a)(2)(x) Text) j f

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20.405(a)(1)(v) ,,_,, 50.73(a)(2)(lin) _,,_

ff f LICENSEE CONTACT FOR THl$ LER (12) 1ELEPHONE WupBE L Name AP.EA CODE Larry Wntis. Technical Staff Ennineer, extension 2701 6 l 1 15 315171-l6171611 j

j Co@LETE ONE LlWE FOR EACH C090NENT FAILURE DESCRIBED IN THIS REPORT (13)

CAUSE SYSTEM COMPONENT MANUF AC. REPORTABLE ,

CAUSE SYSTEM COW ONENT MANUFAC. REPORTABLE TURER TO NPRDS YURER TO WPRDS 1 l l N l I i i l l 1 X El A 1 l l l l I l l I I l l l l l l l

( Expected Month l Day l Year

$UPPLEMENTAL REPORT FXPECTED (14)

Submission

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lyes (If ves, r = nlete EXPECTED SUBMI5510N DATE) Yl NO I ll ll ABSTRACT (Limit to 1400 spaces, i.e, approximately fifteen single-space typewritt.tn lines) (16)

At 1706 hours0.0197 days <br />0.474 hours <br />0.00282 weeks <br />6.49133e-4 months <br /> on Novenber 1,1989, with Unit I defueled and Unit 2 in Operational Condition 1 (Run) at 100E power, the System Auxl11ary Transformer feed to bus 142Y was tripped open when an Equipment Operator closed the door containing the Bus 142Y undervoltage relays, neutral overcurrent relays and degraded voltage relays. The door was misaligned causing difficulty in closing the door. Loss of Bus 142Y caused Reactor Building Ventilation (VR) Isolations on both Unit I and Unit 2. Unit 2's Standby Gas Treatment (58GT) auto started. Unit 1 58GT did not euto start because its power supply was lost (142Y). $8GT Wide Range Gas Monitor (WRGM) power was also lost, so Chemistry Service Department was notified to pull sagles (todine and particulate). This event did not initiate a fast transfer to Bus 142K, via the cross-tle breaker (not a safety function), nor did the Diesel Generator (DG) 1A automatically start. (DG 1A was out-of-service for l maintenance.) At 1745 hours0.0202 days <br />0.485 hours <br />0.00289 weeks <br />6.639725e-4 months <br /> on November 1, 1989, the bus was energized and Bus 142Y was returned to service.

i The auto transfer circuit will be tested. The relays mounted on Bus 142Y cubical door 2 will also be tested toseeifatripsignalcanbereproducedbyjarringthecubicaldoorandthecubicaldoorwillberepaired.

I This event is reportable pursuant to the requirements of 10CFR50.73(a)(2)(lv) due to the actuation of an Engineered Safety Feature System.

W 7

. , f Fors hev 2.0 thCinEE EVENT REPORT (LER) TEXT CONTINUATION 00CKET NupeER (2) LER 1RpeElt t6) Pm Cl) <

FACILITY INNE (1) I Year /// Segeential ff//j/ Revision fff

/// theter /// Nester _  ;

o i 5 I o I o 10131713 eIt - o1215 - oIo of 2 0F 013

% 11e county station unit 1 l

TEXT Energy Industry identification Systan (Ell 5) codes are identified in the test as [XX)

' PLANT AND SYSTEM IDEN118 ICAil0N General Electric - telling Water Reactor ,

EnergyindustryidentificationSystem(EIIS)redesareIdentifiedinthetextas[XX).

A. CON 01110N PRIOR TO EVENT Event Date: 11/01/09 Event ilme: 1707 Hours Unit (s): 1/2 .

Defueled/Aun - Power Level (s): OFl005 Reactor Mode (s): Defueled/l Mode (s) Name:

B. DESCRIPil0N OF EVEN.T j

On leoventier 1, 1999 at 1706 hours0.0197 days <br />0.474 hours <br />0.00282 weeks <br />6.49133e-4 months <br /> with Unit 1 defueled and Unit 2 in Operational Condition 1 (Run) at '

100E power, an Equipment operator (E0) after removing an out of service, attempted to close a dcor on

$witchgear (Ster) 142Y (AP) [EA) Cubicle 2 and found that the door was cocked. This caused this door to i

contacttheadjacentdooratthetopwhichpreventedthedoorfromclosing. While the E0 was atteepting to insert the doors closin0 bolt, he heard the noise of breakter (ACS) 1422 (System Auxillary Transfotiner feed to Bus 142Y) tripping.

There was no indication that the 142X/l42Y cross-tie breaker, AC81425, attempted to close to fast transfer to tus 142X as designed. This resulted in the loss of 400 volt Busses 134X,134Y,136X and associated Motor Control Centers (MCC's), as well as Sus 142Y. ,

i. Loss of bus 142Y caused a Reactor Buildlag Ventilation (VR) [VA) isolation on Unit 1 and 2 due to a loss of Reactor Protection System (RPS) [VC) Sus S. Unit 2StandbyGas1reatment($9G1)[BH]autostarted, however, Unit 1 $0GT did not start because the AC power supply which powers its equipment was lost.  ;

58G1 Wide Range Gas Monitor (hfl0M) power was also lost, so the Chemistry Services Department was notified to take appropriate samples.

OleselGenerator(OG)[EX)lAwasoutofservicefortheinstallationofamodificationandmaintenance at the time of the loss of bus 142Y and therefore the diesel did not start. I f

l C. APPARENT CAUSE OF EVENT L'

The apparent cause of the loss of bus 142Y was due to alsallgrument of the door on the auxiliary compartment of SWOR 142Y, cubicle 2. This alsalignment made the door difficult to close. In the process of closing the door the Bus 142Y pmtective relays mounted on this door may have been jarred causing one or more of the contacts to momentarily close.

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a .;. -

Fors Rev 2,0

. LICENSEE EVENT REPORT (LER) TEXT CONTINuAfl0N LER WumER (6) Pane (3)

. FACILITY WE (1) DOCKET NUSER (2)

Year ffj/

// Sequential f/j/j/ Revision

/// thster /// thseer 0.1 5 1 0 1 0 1 0 1 31 71 3 8I9

- 01215 - 0I0 01 3 0F 01 3 i m IIe t - tv Station unit 1 TEXT Energy Industry identification System (Ell 5) codes are identified in the text as (KX] I l

j

0. SAFETY ANALYSIS OF EVENT The bus was not required to be operable for Unit 1 at this time because Unit I was defueled. At the time of the event, Unit 2 was in a timeclock for the 1A DG Division 2 outage. The loss of power did effect common egulpment r w ired for Unit 2 operation. Power to the equipment that was lost was quickly restored (within I hour). If this event would have happened while Unit I was in operation, the fast transfer to tus 142X may have occurred (however this is not a safety function) or DG IA would have auto started and picked up any of the tus 142Y essential loads, i E. CORRECT!vE AC110NS l

At 1720 hours0.0199 days <br />0.478 hours <br />0.00284 weeks <br />6.5446e-4 months <br /> the isolations were reset and VR was restarted onControl The "B" Unit 2Room onceand "B"Auxillary Reactor Protection System (RPS) [YC] was transferred to an alternate power source.

Electric Equipment Room Ventilation (VC/VE) [VI) was started at 1720 hours0.0199 days <br />0.478 hours <br />0.00284 weeks <br />6.5446e-4 months <br /> to ensure it operated properly because the loss of Dus 142Y caused "A" VC/vE to de-energize.

' At 1745 hours0.0202 days <br />0.485 hours <br />0.00289 weeks <br />6.639725e-4 months <br /> tus 142Y was energized and the 58GT WRGM was restarted. At 1750 hours0.0203 days <br />0.486 hours <br />0.00289 weeks <br />6.65875e-4 months <br /> "A" VC/VE was restarted.

Unit 2 58GT was lef t running for approximately 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> so that the Chemistry Service Department could take lodine and particulate samples.

I bus 142Y auto transfer circuit logic will be tested to verify proper auto transfer operation (in particular the tus 142Y/X cross-tie breaker, ACB 1425, auto closing circult). Bus 142Y protective relays will also be tested to see if any of the relays produce a trip signal when they are ,larred.

Action item Record (AIR) 373-200-89-10401 will track conpletion of these tests and docisment conclusions derived from them.

The cubicle door will be repaired per Work Request L94322 and tracked by AIR 373-200-89-10402,

f. PREVIOUS EVENTS None.

G. COMPONENT fAlLURE DATA None.

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