ML20215A995

Potential Significant Deficiency Rept 87-15 Re Failure of Main Steam Valve Area Supply Fans to Start Automatically. Initially Reported on 870508.Diesel Sequencer Interlock Rewired to Open Dampers.No Addl Repts Anticipated

ML20215A995
Person / Time
Site:	Beaver Valley
Issue date:	06/02/1987
From:	Carey J DUQUESNE LIGHT CO.
To:	Russell W NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
References
2NRC-7-153, 87-15, NUDOCS 8706170179
Download: ML20215A995 (3)

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2NRC-7-153

-(412)393-7546 Beaver Valley No. 2 Unit Project Organization j Telecopy(412) 393 7889 'j l $,Gf,Bugng Shippingport, PA 15077.-

June 2,'1987 j

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~ United States Nuclear Regulatory Commission

. Region I

'631 Park Avenue-King: of Prussia. PA -19406

' ATTENTION: ..Mr. William T. Russell-e Administrator

SUBJECT:

Beaver Valley Power._ Station - Unit No. 2-Docket No. 50-412 Failure of Main Steam Valve Area Supply Fans' Operation Following Loss of Offsite Power Potential Significant Deficiency Report 87-15

-l Gentlemen:-

This _ Potentially Reportable Significant Deficiency . Report is being .

submitted' pursuant' to the requirements of 10CFR50.55(e).

It is anticipated that no addition _al reports will be required. .

1 DUQUESNE LIGHT COMPANY' By V d. J.' Carey v Sr. Vice President 1 DLC/ijr NRC/DLC/SDR/8715 Att i ent AR/ AR'

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Mr. P. Tam, Project Manager (w/a)

_Mr.. J. M. Taylor', Director (3) (w/a)  !'

.Mr. J.'Beall, Sr. Resident Inspector (w/a)

Mr. L. Prividy, NRC Resident Inspector (w/a)

INP0' Records Center (w/a)

NRC Document. Control Desk (w/a) 8706170179 870602 7 1 PDR ADOCK 05000412 I I l

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ATTACHMENT

1. Summary

'The . main steam valve area supply fans 2HVR*FN206A&B failed to start automatically, as required, from the diesel loading sequencer because their associated dampers 2HVR*M00201A1, 81, 201A, B, and 202A, B which must be open for the fans to start do not. open automatically following a loss of offsite power.

2. Immediate Action Taken ACN 0-5137 has been issued to rewire the diesel loading sequencer inter-lock to allow the dampers to open and supply fans to start, as required, following a loss of offsite power.

Mr. L. M. Rabenau, Lead Compliance Engineer, Beaver Valley Power Station i Unit No. 2, contacted Mr. L. Tripp, NRC Region I, of this concern on May 8, 1987. l i

3. Description of Deficiency f The main steam valve area supply fans, 2HVR*FN206A&B, are interlocked with their associated dampers, 2HVR*M00201A1, B1, and 201A, B, and 202A, B, such that the dampers must be open for the fans to start. Following a loss of offsite power, the fans receive an auto start signal from the diesel sequencer logic but the dampers do not. The fans cannot start '

automatically because the dampers remain closed.

4. Analysis of Safety Impac_t Lack of ventilation in the main steam valve area due to failure of the supply fans would result in an increase of temperature above design limits for . the area. This would lead to accelerated thermal aging of safety-related equipment and could result in premature, thermally-induced failure and loss of associated safety functions. This constitutes a deficiency in plant design which, were it to have remained uncorrected, could have ,

adversely affected the safety of operation of the plant.

5. Corrective Action to Remedy Deficiency The diesel . sequencer interlock has been rewired to open dampers 2HVR*M00201A1, B1, 201A, B and 202A,B from the diesel sequencer logic.

The supply fans 2HVF*FN206A, B are slaved from damper position, starting when the dampers are open and tripping when the dampers are closed. Tnis supplies ventilation to the main steam valve area following a loss of offsite power, as required. Reference ACN D-5137 for modification.

6. Additional Report This is a final report. No additional reports are anticipated.