05000412/LER-1990-022, :on 901019,discovered Inadequate Electrical Isolation Between Control & Protection Circuits

:on 901019,discovered Inadequate Electrical Isolation Between Control & Protection Circuits

ML20062F053
Person / Time
Site:	Beaver Valley
Issue date:	11/19/1990
From:	Noonan T DUQUESNE LIGHT CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-90-022, LER-90-22, ND3MNO:3061, NUDOCS 9011270076
Download: ML20062F053 (6)

LER-1990-022, on 901019,discovered Inadequate Electrical Isolation Between Control & Protection Circuits

Event date:
Report date:
4121990022R00 - NRC Website

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Shippingwt PA 15onW November 19, 1990 4

ND3MNO:3061 i

Beaver Valley Power Station, Unit No. 2 Docket No. 50-412, License No. NPF-73 LER 90-022-00 United States Nuclear Regulatory Commission Document Control Deck Washington, DC 20555 Gentlemen:

In accordance with Appendix A,

Beaver Valley Technical Specifications, the following. Licensee Event Report is submitted:

LER 90-022-00, 10 CFR 50.73.a.2.ii.B, " Inadequate Electrical Isolation between Control and Protection Circuits".

Very_truly yours, T.

P. Noonan General Manager Nuclear Operations s1 Attachment 901127I:)b76 901119 f

Ff0R ADOCK 05000412

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5 PDC

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s Novemb3r.19, 1990-ND3MNO:3061 Page two cc: Mr. T. T. Martin, Regional Administrator United States Nuclear Regulatory Commission Region 1 475 Allendale Road i

King of Prussia, PA 19406 c. A. Roteck, Ohio Edison i

76 S. Main Street i

Akron, OH 44308 Mr. A. DeAgazio, BVPS Licensing Project Manager 4

United States Nuclear Regulatory Commission Washington, DC 20555 J.

Beall, Nuclear Regulatory Commission, BVPS Senior Resident Inspector Larry Beck Cleveland Electric 6200 Oak Tree Blvd.

Independence, Ohio 44101 INPO Records Center Suite 1500 1100 Circle 75 Parkway Atlanta, GA 30339 G.

E. Muckle, Factory Mutual Engineering 680 Anderson Drive #BLD10 Pittsburgh, PA 15220-2773 Mr. J. N. Steinmetz, Operating Plant Projects Manager Mid Atlantic Area Westinghouse Electric Corporation-Energy-Systems Service Division Box 355 Pittsburgh, PA 15230 Mr. Richard Janati Department of Environmental Resources-P. O.

Box 2063 16th Floor, Fulton Building Harrisburg, PA 17120-Director, Safety Evaluation & Control Virginia Electric & Power Co.

P.O.

Box.26666 One James River Plaza Richmond, VA 23261

Novcmbar if, 1990 ND3MNO:306'.

• Page threr.

l W. Hartley l

Management Analysis Company 112671 High Bluff Drive l

San Diego, CA 92130-2025 l

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t J. M. Riddle NUS Operating Service Corporation Park West II Cliff Mine Road Pittsburgh, PA 15275 l

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I RC Pg 300 U.S. NUCLE AR f.51 ult TLAY COMMIS5lON APPROvtD oms NO 3160 0104 l

IKPl7 El 4/30/92 ESTIMATED BURDEN PER KtSPONSt TO COMPLY YtTH THIS LICENSEE EVENT REPORT (LER)

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THE PAPERWORK REOUCTION PROJECT 0 16041041 OF F ICE OF MANAGEMENT AND BUDOti, W ASHINOTON. DC 20603.

FACILITY NAME til

' DOCK S T NUMSE R (21 PAGE (3i Beaver Valley Power Station Unit 2 oi5l0loIol411l2 1 lOFl 013 flTLE 141 l

Inadequate Electrical isolation between Control and Protection Circuits tytNT Daf t (El LIR NUMetR tel REPORT DAf t 17)

OTHER 7 ACILITIES INVOLvtD tel MONT H DAY YEAR YEAR

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• Hvi 50.73teH2Hdel 60.73 eH2Hal LICENSEE CONTACT FOR THil EER (til NAME TELEPHONE NUMetR AHE A COOS T.P. Noonan, General Manager Nuclear Operations 4 1 1l2 6l 4 1 3l-t 1l2l5l8 COMPLEf t ONE LINE FOR E ACH COMPONENT F ALLURE DESCRittD IN TH18 REPORT (131 m

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A T R ACT u,-,..,m e.. e. e.,,...,, e.,,,,Me., e.,*.,*,*,v r,mo,.eo n el During an engineering review for a

design change between the control and protection circuits associated with the Containment High Pressure bistables, - no documentation could be located for the electrical isolation qualification of the existing interface device (Westinghouse 7300 NCT card part #2837A91)

Westinghouse was contacted on-10/39/90 and verified that the listed card had never been qualified as an isolation device.

Qualified isolation devices have been installed in the circuits.

If a fault had occurred in the control (annunciator) portion of the circuit, it potentially would have affected - the operability of the Containment High Pressure protection circuite D

i NRC Form 3541640 l

1 wn,c *oaM sesA u.s. wuctaAn is vu tony coMMierios.

exnzi, oa LlcENSEE EVENT REPORT (LER)

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o TEXT CONTINUATION i#'"4,'/11*MMjuUt%R'c'"','!df v"'"MfA P PE RWO Ri JT N RJ h 6.

II IC OF MANAGEMENT AND SUDGtY.W ASHINGTON,DC 2060J.

f ACitiTV hAMt (H DOCK t Y NUMDER (21 LE A NUMetR ($)

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Beaver Va' ley Power Station Unit 2 0161010 l o l 411 l 2 9l0 0!2l2 0l0 0 12 0F Ol3 text <n

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m.wime r, asam on Description of Fvent During Beaver Valley Unit 2's second refueling outage, a design change was installed ta provide control room indication when the Refueling Water Storage Tank The RWST is(RWST) Low-Low Level bistables are placed in bypass.

used as the initial water source for the Coatainment Depressurization and Quench Spray system.

In the

coursc, of the engineering review associated with this design L

change, the isolation qualification of four cards used in the containment Pressure Hi-3 bistables' circuitry was questioned.

These bistables are used to actuate the quench spray system in the event of high containment pressure.

The involved cards are Westinghouse 7300 NCT cards part #2837A91, the comparator trip switch cards for containment pressure protection (channels 2LMS*PTD950, 2LMS*PTD951, 2LMS*PTD952 and'2LMS*PTD953).

Outputs from these cards also cJo to control circuitry (annunciators) associated with high containment pressure.

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After documentation on site could not be located concerning the electrical isolation capabilities of these cards, Westinghouse was questioned about this matter on 10/10/90.

On 10/19/90, Westinghouse verified that the NCT cards had never been qualified z

as isolation devices.

Based on

this, a qualified isolation device (Westinghouse ANI6 card) was installed in each circuit between the output of the NCT cards and the annunciators.

Cause of Event

This event was due to a design error in directly' connecting the control and protection circuits for the containment high pressure bistables.

Corrective Actions

1)

As stated above, qualified isolation devices have been installed in the circuits.

These devices will prevent a

fault in the annunciator part of the circuit from affecting the protection functions.

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.N GXT1%ES 4/30/97 LICENSEE EVENT REP 3RT (LER)

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TEXT CONTINUATION 2Nt"n't,&%"u'21"oME"f'.M!'c'n,'!d l,".'"'CNf!

1 P A,E RWO m t puCTION 6

Of MANAGEMENT AND BUDGET. WASHINGTON. DC 20603.

P AC.Lif Y NAM 4 Of DOCKit NVM.tR (23 LtR NUMetR let PA06 (3) d'"

No vva n Beaver Valley Power Station Unit 2 01510 l 0 l 0 l 4 l1 l 2 9l0 0l2l2 0l0 013 0F 0l3 TEXT wni an N w

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Previous Similar Events

Review of station documents identified no previous similar events.

Event Reportability Due to a design error, a fault in the annunciator control circuit could have resulted in a failure of the containment high pressure l

protection circuit. -Based on this potential this event is being reported under 10CFR50.73.a.2.ii.B

(" Condition that was outside the design basis of the plant").

Additionally, the station is reviewing this event to determine

reportability

per 10CFR21.21

(" Notification of failure to comply").

I

Safety Analysis

A failure of the control / annunciator portion of the circuit may have induced a fault in the Containment High Pressure protection circuit.

This fault could.potentially have affected all four channels of containment high pressure protection, defeating the automatic initiation of the. Containment Depressurization System.

NRC Perin 306A (649s