05000334/LER-1980-073, Discusses LER 80-073/01P on 801003.Potential Exists for Blowing More than One Steam Generator in Event of Single Line Break in RHR Valve or in Steam Supply to turbine-driven Auxiliary Feedwater Pump.Engineering Study Is in Prog

Discusses LER 80-073/01P on 801003.Potential Exists for Blowing More than One Steam Generator in Event of Single Line Break in RHR Valve or in Steam Supply to turbine-driven Auxiliary Feedwater Pump.Engineering Study Is in Progress

ML19347B339
Person / Time
Site:	Beaver Valley
Issue date:	10/03/1980
From:	Werling J DUQUESNE LIGHT CO.
To:	Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
References
BVPS:JAW:998, NUDOCS 8010140432
Download: ML19347B339 (2)

LER-1980-073, Discusses LER 80-073/01P on 801003.Potential Exists for Blowing More than One Steam Generator in Event of Single Line Break in RHR Valve or in Steam Supply to turbine-driven Auxiliary Feedwater Pump.Engineering Study Is in Progress

Event date:
Report date:
3341980073R00 - NRC Website

text

,a

&s!' f* &

4 s. 5 i.*

pin 4se-sooo us s......~

Patsewg* Ps

' n" DUQUESNE LIGHT COMPANY Beaver Valley Power Station Post Office Box 4 Shippingport, PA 15077 October 3, 1980 BVPS: JAW:998 Beaver Valley Power Station, Unit No. 1 Docket No. 50-334, License No. DPR-66 LER 80-073/01P Mr. B. H. Grier, Director of Regulation United States Nuclear Regulatory Commission Region 1 631 Park Avenue King of Prussia, Pennsylvania 19406

Dear Mr. Grier:

In accordance with Appendix A, Beaver Valley Technical Specifications, Licensee Event Report LER 80-073/0lP, Technical Specification 6.9.1.8.e, Administrative Controls, is submitted. This occurrence was reported to Mr. D. A. Beckman, the Beaver Valley Resident Inspector, at 1045 hours0.0121 days <br />0.29 hours <br />0.00173 weeks <br />3.976225e-4 months <br /> on October 3, 1980.

We have been informed by Westinghouse that there is a potential for blowing down more than one steam generator in the event of a single pipe break in either the header for the Residual Heat Release valve or for the steam supply to the turbine-driven auxiliary feedwater pump. This may comprise an unreviewed safety question as defined in 10 CFR 50.59.

A pipe break in the steam supply header to the turbine-driven auxiliary feedwater pump would be unisolable because of the manual isolation valves and the check valves being located in the main steam valve room.

A pipe break in the Residual Heat Release System at the header or downstream of each respective check valve would be unisolable.

6 8*1om 43 a

y..

Mr. B. H. Crier October 3, 1980 BVPS: JAW:998 Page 2 The consequences of this event would be that all steam generators that supply the headers would depressurize. The auxiliary feedwater pumps are initiated on low-low steam generator water level or on a safety injection signal.

Assuming the loss of the turbine-driven auxiliary feedwater pump due to a loss of steam supply, the motor-driven auxiliary feedwater pumps would deliver against a backpressure corresponding to the depressurized steam generators. The motor-driven pumps could potentially run out and trip off due to high electrical loads, thus resulting in a loss of all auxiliary feedwater secondary heat removal capability. The auxiliary feedwater pumps at Beaver Valley are equipped with discharge throttle valves which would prevent this occurrence. Other consequences of this occurrence which will be considered are: a) radiological releases resulting from multiple uncontrolled steam generater blowdown; b) core thermal response due to multiple uncontrolled steam generator blowdown; and c) core cooling capability following multiple uncontrolled steam generator blowdown.

An engineering study of this is co==encing immediately to determine the extent of the problem and to recommend corrective actions.

This report is being submitted under Technical Specification 6.9.1.8.e, Administrative Controls, and may also be reportable under 10 CFR 21 since it may be applicable to other facilities.

Very truly yours, A. Werling Superintendent Director Of Management & Program Analysis w/

ec:

United States Nuclear Regulatory Commission Washington, D. C 20555 W. J. Ross, BVPS Licensing Project Manager United States Nuclear Regulatory Co= mission Washington, D. C.

20555 D. A. Beckman, Nuclear Regulatory Commission, BVPS Site Inspector P. Higgins, Secretary, Prime Movers Cocsittee - EEI Nuclear Safety Analysis Center, Palo Alto, California Mr. John Alford, PA Public Utilities Co= mission, Harrisburg, PA 1