ML20005E453

LER 89-022-00:on 891128,HPCI Declared Inoperable Following Unexpected Actuation of HPCI Pump Room Deluge Sys.Actuation Caused Dc Sys Grounds Due to Moisture Intrusion in Electrical Equipment.Equipment dried.W/891228 Ltr

ML20005E453
Person / Time
Site:	Quad Cities
Issue date:	12/28/1989
From:	Bax R, Hill K COMMONWEALTH EDISON CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-89-022-02, RLB-89-287, NUDOCS 9001050262
Download: ML20005E453 (6)

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.. Commonwealth Edison 3

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'l22710 206 Avenue North - .

< Cordova, luires 61242 0740

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Telephone 309454 2241' 3

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. RLB-89-287i j '

December.28, 1989

, , c 'Ui S;; Nuclear _ Regulatory Commission '

Document Control Desk .!

Hashington, DC 20555

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Reference:

-Quad Cities Nuclear Power Station- l Docket Number 50-254, DPR-29, Unit One j

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Enclosed:is: Licensee Event Report (LER)89-022, Revision 00, for Quad Cities '

Nuclear Power Station. This report covers a deluge actuation resultingiin >

, High Pressure Coolant Injection system incperability and the fire suppression )

system outage-notification. {

This report is submitted in accordance with the requirements of the Code of-. o Federal Regulations, Title 10. Part-50.73(a)(2)(v): The licensee shall report '

any. event or condition that alone could have prevented the fulfillment of the f . safety, function -of- structures or systems that are needed to mitigate- the' l

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consequences of an accident; and Technical Specification 3.12.C.3: Restore 1

theisystem (fire suppression system) to operable status within-14 days or 1

. prepare- and submit a report to the Coniission pursuant to 1 Specification-6.3.A.1 within the next 30 days.  ;

Respectfully, COMMONWEALTH EDISON COMPANY I QUAD CITIES NUCLEAR' POWER STATION h-R. L. Bax Station Manager RLB/MJB/ad Enclosure

.,' cc: R. Stols R. Higgins INPO Records Center NRC Region III gM

groR8BESEiS!!B84 s ]

ho LittNSEE EVENT REPORT (LER)

Farm Rev 2.0 g Faciljty.Name (1) DMket Number (2) Pace f31

^" " titiet Unit One al El 01 01 01 21 El 4 1 of 0 E title (4)

Unit One HPCI Inonerable Due to inadvertent Delune System Actuation i Event Data fE1 LER *

• r (6) Reoort Date (7) Other Facilities involved fB)

Month Day Year- Year Sequential / Revision Month Facility Names {

/ Day Year Docket Numberft) j/j/j/

// **r j////jj/ Number 01 Sl Of DI 01 l l

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11 1 l21 ni 4 I I .; 0l2 6 2 0 10' 1 I2 21 B Bl 9 Of SI 01 01 01 l l TH!s REPORT !s suSMITTED PuR$uANT TO THE REQu!REMENTS OF 10CFR (Check one or more of the followino) (11) t 4 20.402(b) 20.405(c)

_ 50.73(a)(2)(iv) 73.7)(b)

POWER _ 20.405(a)(1)(1) 50.36(c)(1) L 50.73(a)(2)(v) 73.71(c)

LEVEL 20.405(a)(1)(11) _. 50.36(c)(2) 50.73(a)(2)(vii) _L Other (specify (101 0 0 20.405(a)(1)(iii) 50.73(a)(2)(1) 1 50.73(a)(2)(viii)(A) in Abstract

_., 20.405(a)(1)(iv) _ 50.73(a)(2)(It) 50.73(a)(2)(viii)(B) below and in 20.405(a)(1)(v) 50.73(a)(2)(iii) 50.73(a)(2)(x) Text)

LICENSEE CONTACT FOR THIS LER (12)

Name TELEPHONE NUMBER AREA CODE K.'J. Hill. Technical Staff Enoineer. Ext. 2150 3 10 19 61 $! 41 -l 21 21 41 COMPLETE ONE LINE FOR EACH COM ON NT FAILURE DESCRIBED IN THIS REPORT f131 CAusE ' SYSTEM c0MPONENT MANUFAC- REPORTABLE / CAuSE SYSTEM COMPONENT MANUFAC- REPORTABLE TURER TO NPRDS /p TURER TC NPRDS l 1-l l l l l Y / l l 1 l l l l l l l l l l 'l / l l l l l l l SUPPLEMENTAL REPORT EXPECTED f14) Expected Month l Day l Year submission lyes fif ves. conolate EXPECTED SUBMISSION DATE) x ! NO l l l ABSTRACT-(Limit to 1400 spaces. i.e. approximately fifteen single-space typewritten lines) (16) '

At 0910 hours0.0105 days <br />0.253 hours <br />0.0015 weeks <br />3.46255e-4 months <br /> on November 28, 1989, the Unit One High Pressure Coolant Injection (HPCI) system was declared inoperable following an unexpected actuation of the HPCI Pump Room Deluge system. The actuation caused DC system grounds due to moisture intrusion in the various turbine auxiliary electrical equipment. The actuation occurred while operating personnel were in the process of returning the deluge system to service.

The root cause of the HPCI deluge actuation is not known. The electrical equipment affected by the deluge actuation was tested and dried as necessary to remove the DC grounds. The HPCI system was successfully tested and returned to service at 1045 hours0.0121 days <br />0.29 hours <br />0.00173 weeks <br />3.976225e-4 months <br /> on December 1, 1989.

Corrective actions will include a procedure revision and operator training.

The deluge system remains out of service to allow installation of a preaction system to prevent any future inadvertent actuations. Fire watch frequency will be increased and a temporary procedure will be initiatad. On December 11, 1989, the period of time that the deluge system was inoperab!e exceeded the 14-day reporting requirement of Technical Specification 3.12.C.3.

This event is being submitted in accordance with 10CFR50.73(a)(2)(v)(D) and Technical Specification 3.12.C.3.

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Litthift EVENT REPORT fLER) ftXT CONTINUAT10M Form Rev 2.0,,

j FACILITY.NAME (1) DOCKET NUMBER (2). LER NLBERER f A1 Pane (1)

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Year // seguential // Revision p/j/j

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/ W er thaad Citiet Unit One 0 I $ 1 0 l 0 l 0 1 21 El 4 Bl9 - 0l 2l2 - 0l0 Ol' 2 0F 01 E .

.. TEXT ' ' Energy Industry Identification-system (E!!s) codes are identified in the text as [xX)

-PLANT:AND SYSTEM IDENTIFICATION:

General Electric - Boiling Water Reactor - 2511 MWt rated core thermal power.

EVENT IDENTIFICATION: Unit One HPCI Inoperable Due to Inadvertent Deluge System Actuation

'A. = CONDITIONS ~ PRIOR TO EVENT: ,

Unit: One Event Date: November 28, 1989 Event-Time: 0910 i Reactor Mode: 4 Mode =Name: RUN Power Level: 10%

This; report was initiated by Deviation Report D-4-1-89-112 and Supp. 1.

RUN Mode (4) - In this position -the reactor system pressure is at or above 825 psig- and the reactor protection system is energized, with APRM protection and RBM interlocks in service (excluding'the 15% high flux scram).

B.. DESCRIPTION OF EVENT:

At 0910 hours0.0105 days <br />0.253 hours <br />0.0015 weeks <br />3.46255e-4 months <br /> on November 28,.1989, Quad Cities Unit One was operating in the RJN modeLat approximately 10 percent reactor [RCT] thermal power. At this time, the Unit One High Pressure Coolant Injection (HPCI) [BJ) Pump [P] Room Fire Suppression

~ Deluge System.[KP] actuated while operating personnel were in the process of

• returning the system to service.

The HPCI.-deluge system is an open head dry pipe system which consists of seven thermal detectors (DET), an alarm [ ALM] check valve [ISV) and associated piping

[ PSF] and spray nozzles [NZL). The thermal detectors and spray nozzles are spaced

.along the perimeter of the HPCI pump and turbine [TRB].

Prior to this' event, at 0645 hours0.00747 days <br />0.179 hours <br />0.00107 weeks <br />2.454225e-4 months <br /> on November 26, 1989, the Unit One HPCI Deluge 1 system automatically actuated during performance of 005.2300-7, HPCI System Turbine Overspeed Test. Because the HPCI system had been declared inoperable to perform the overspeed test, the event was nonreportable.. The deluge system was taken out of. service and a fire watch initiated as required by Technical Specification 3.12.C.2. The cause of the event had been determined to be a damaged thermal detector which caused the detector to trip at a temperature of 91 degrees Fahrenheit instead of the original setpoint of 190 degrees Fahrenheit. The system actuated as a result of room temperature increase from operation of the turbine for the overspeed test. The damaged detector was replaced and the system was being returned to service when the second actuation occurred.

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LICENEEE EVENT REPORT (LER) TEXT CONTINUATION ' Form Rev 210 k fFACIt!TY NAME (1). lDOCKETNUMBER(2) LER NUMBER f6) Pane (3)

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/// Number /// Number Ouhd cities Unit One' O lE10l0 1 0 l 2l $1 4 8l9 - Ol2l2 - 010 of 3 0F 0[,,$

, .TExis -Energy Industry Identification system (E!!s) codes are identified in the text as [XX)

LThe-deluge system actuation on November 28, 1989, occurred as Operating personnel

'were in the process of returning the system to service after the previous event '

described above. The Equipment Attendant (EA) who was assigned the return to '

service found the deluge manual ~ isolation valve closed as expected and noted that a

< paper card was inserted between the valve [V) stem and a tamper switch [333 mounted '

C on the valve stem. The card had apparently been placed in order to silence the

, system trouble horn [ ALM] which is not the preferred practice. Normally the supervisory relay is blocked:to silence the system trouble alarm. The EA then '

proceeded.to return the system to service in accordance with QOP 4100-4, Resetting

Fire System Deluge Valve. After checking the latching mechanism and verifying the valve was properly reset, the EA' slowly opened the valve until water could be hoard to fill the chamber. The EA stopped opening the valve and made a visual check of  ;

!> the room to verify no water was being discharged from the spray nozzles. Following- -

.the visual check, the.EA proceeded to fully open the valve. However, before the

' valve was full open,.the card inserted between the valve stem and tamper switch [

fell out and the deluge system trouble horn sounded and fire alarm gong [ ALM] '

actuated indicating the system had actuated. The EA immediately closed tne valve to stop the spraying of water in the HPCI room.

The actuation of the deluge system resulted in the receipt of a 125 U C system ground alarm [ ALM] in.the Control Room which was caused by moisturr intrusion into the miscellaneous DC equipment in the HPCI room. The HPCI system was declared ,

inoperable at 0910 hours0.0105 days <br />0.253 hours <br />0.0015 weeks <br />3.46255e-4 months <br /> on November 28, 1989,-and HPCI System Outage Report,

QOS 2300-01 was initiated. Work Request 080367 was written for Electrical Maintenance personnel to megger the DC equipment to detect any electrical shorts to ,

ground. :NRC notification of the HPCI system inoperability was completed via the Emergency Notification System (ENS) phone system at 1013 hours0.0117 days <br />0.281 hours <br />0.00167 weeks <br />3.854465e-4 months <br /> on November 28, l 1989, to comply with the requirements of 10CFR50.72(b)(2)(111)(D).

l L At 1030 hours0.0119 days <br />0.286 hours <br />0.0017 weeks <br />3.91915e-4 months <br /> on November 28, 1989, the HPCI DC motors located in the room were I

taken out of service. This. Included the turbine turning gear [TGR), turbine L auxillary oil pump-[P),' emergency bearing oil pump [P) . turbine gland seal leakoff ,

l: blower [BLO), gland seal condensate pump [P], turbine motor speed changer [M03-and l motor gear unit [M0]. Of the motors checked, only the gland seal leakoff blower-exhibited indications of a ground; however, the motor was subsequently dried and I readings returned to normal.

L The HPCI deluge system temperature switches were functionally tested per Temporary Procedure 5994 by Instrument Maintenance personnel. All the temperature switches  :

L were found to trip at temperatures well above the ambient temperature of the room.

The switches were inspected for damage; none was found.

I> Personnel inside the room at the time of the deluge actuation did not observe any steam leaks or other heat sources which could have tripped the temperature switch.

, Ambient temperature at the time of the actuation was estimated to be 90 degrees Fahrenheit.

Mechanical Halntenance personnel removed all the spray nozzles, connected a drain hose to one nozzle fitting and plugged all others. The EA involved with the event then reset the multimatic valve under observation of the Station Fire Marshal and his action was determined to be correct in accordance with the procedure. The system was lef t in operation with the plugs installed for a 24-hour period and no problems were observed.

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' LICENSEE EVENT REPOR7 fLER) TEXT CONTINUATION Form Ray 2ID k.

FAc!)!,7YNAME(1);  : 00cKET NuPSER (2) LER NLMIER f6) Pana (1)

I Year /// sequential Revision

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, /// Number / Number 4 Duad cities Unit One o i $'l 0 l 0 1 0 1 21 El 4 8I9I -

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' TEXT Energy Industry.!dentification system (E!!s) codes are identified in the text as [XX] ,

A chart ~ recorder was-connected to the deluge control circuit and the EA's actions were repeated with a card placed between the tamper switch and the valve stem. '(he

. card ~ fell out as'it did during the event, but the system did not trip. The switch was manually operated more than seven times with no resultant system actuation;

! however, the chart recorder did detect small voltage spikes in the deluge control '

system. .The plugs were removed from the piping and the nozzles reinstalled; however, the deluge valve remains out of service in order to prevent an inadvertent actuation.

.At 1045 hours0.0121 days <br />0.29 hours <br />0.00173 weeks <br />3.976225e-4 months <br /> on December 1, 1989, the Unit One HPCI system was successfully tested ,

and returned _to service. The HPCI system outage report was terminated.

The Ubit One HPCI deluge system remained out of service, and a fire watch was initiated as required by Technical Specification 3.12.C.2, in order to allow time to evaluate the existing system to determine if the system can be modified to prevent any future inadvertent actuations. On December 11, 1989, the period of time that the deluge system was inoperable exceeded the 14-day reporting

. requirement of Technical Specification 3.12.C.3.

j C.- APPARENT CAUSE OF EVENT:

The HPCI system inoperability is being reported in accordance with 10CFR50.73(a)(2)(v)(D): The licensee shall report any event or condition that alone could have prevented the fulfillment of the safety function of structures or' 1 7 ' systems that are needed to mitigate the consequences of an accident. The fire

. sprinkler- system being inoperable greater than 14 days is being reported in accordance with Technical Specification 3.12.C.3: " Restore the system to operable 4

! status within 14 days, or prepare and submit a report to the Commission pursuant to l Specification 6.3.A.1 within the next 30 days outlining the cause of inoperability, the action taken, and the plans for restoring the system to operable status."

!. The root cause of the HPCI deluge actuation is not known. Many likely causes have been ruled out.- The actuation could have been caused by a trip of one or more of the thermal detectors. However, none of the switches were tripped prior to returning the system to service as it would have prevented the valve from being reset. Personnel in the room did not observe any steam leak or other source of heat which could have caused'a sporadic trip of a switch. Therefore, the actuation

- was not caused by a trip of a thermal switch. The actuation could have been caused by an error by the EA when returning the valve to service in that he may have l ' accidentally-tripped the operating relay for the system as it is located in a small l panel near the deluge isolation valve. This would have required that the EA

physically contact the relay in order for it to trip. The EA repee.ted the l- operation under observation from the station Fire Marshal and the actuation could not be repeated. Since the EA was opening the valve when the actuation occurred, he could not have bumped the operating relay to trip the system.

The actuation could have been caused by a sudden voltage spike in-the control circuit for the deluge system. Minor voltage spikes were detected during testing following the event; however, the magnitude of the spikes was much less than that required for actuation of the deluge solenoid or thermal switch operating relay.

Also, this valve is cycled once per montn for operating surveillance and no problems have occurred.

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LICENCEE EVENT REPORT fLERh TEXT CONTINUATION' Form'Pav 2.0 Fl ~FACILIJY NAME (1)- DOCKET NUMBER (2)' LER NUMBER f6) Pane (3)

'1 h 'f . Year' seguential Revtston g NM r N*r Quad citiet unit one D i 5 1 0 l 0 1 0 l 21 El 46 R19 - 012 l2 - 0l0 al $ OF' of 5

, TEXT, Energy Industry IdentiftCation system (E!!s) codes are.10entified in the text as (XX]

I .D. SAFETY ANALYSIS OF EVENT:

o The safety of the plant and public was not affected during this event. Per Technical Specification 3.5.C.1,-the HPCI subsystem shall be operable whenever the

, , . reactor pressure is greater than 90 psig. After declaring Unit One HPCI inoperable. testing of backup-systems was initiated in accordance with the Limiting W Condition for 0peration as specified in Technical Specification 3.5.C.2. All

~ backup systems were found=to.be operable and all necessary testing was successfully performed until the time that-HPCI was declared operable. Therefore, adequate' y means to shut down the reactor and maintain it in a safe shutdown condition were  !

N available throughout this event, j i

Per Technical Specification 3.5.C.2, continued reactor operation is permitted for a '

period of seven days after the date HPCI it found to be inoperable, provided all required backup systems are operable.

With the Unit-One HPCI Deluge system inoperable, the necessary backup fire suppression equipment was provided and fire watch established in'the area twice per

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shift as required by Technical Specification 3.12.C.2.

E. CORRECTIVE ACTIONS:

The immediate. corrective action consisted of closing the HPCI deluge. valve to stop theLspray of water in.the HPCI room. The Unit One HPCI system and deluge system were taken out of service to investigate the cause of the actuation and determine j the: extent of damage to the. electrical equipment in the HPCI room. All HPCI electrical' equipment sprayed by the deluge system was inspected, tested and dried l as necessary to remove any moisture intrusion. .The HPCI system was successfully 4 tested and declared operable at 1045 hours0.0121 days <br />0.29 hours <br />0.00173 weeks <br />3.976225e-4 months <br /> on December 1, 1989. Procedure ,

L QOP 4100-4 will be revised to provide instructions for the out-of-service of the '

deluge system (NTS 2542008911201). Training will be completed on the procedure

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. revision (NTS 2542008911202). j l;

1- The~HPCI deluge system remains out of service to allow installation of a preaction system to prevent any inadvertent actuation in the future (NTS 2542008911203). As  !

L .a contingency, the fire nozzles will remain installed so the system can be manually  ;

I> operated. A temporary procedure will be written to provide operator action in the  ;

event of a fire in the HPCI pump room (NTS 2542008911204). In the interim, the l fire watch inspections will be increased to once an hour (NTS 2542008911205). j F.- PREVIOUS EVENTS:

nThere have been no previous events involving inadvertent initiation of the HPCI ,

. deluge system.  ;

G. COMPONENT FAILURE DATA:

No component failure could be identified in this event.

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