05000339/LER-1981-010, Forwards LER 81-010/03L-0

Forwards LER 81-010/03L-0

ML19343C043
Person / Time
Site:	North Anna
Issue date:	02/11/1981
From:	Cartwright W VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML19343C044	List: 05000339/LER-1981-010, Forwards LER 81-010/03L-0 05000339/LER-1981-010-03, /03L-0:on 810113,w/unit at 100% Power,Overspeed Trip of Turbine Driven Auxiliary Feedwater Pump Occurred During Surveillance Testing.Caused by Failure of Turbine Governor to Control Speed.Governor Was Replaced
References
N-81-031, N-81-31, NUDOCS 8102180525
Download: ML19343C043 (2)

LER-1981-010, Forwards LER 81-010/03L-0

Event date:
Report date:
3391981010R00 - NRC Website

text

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t VIRGIN 6 A ELECTRIC AND POWER COMPANY NORTM ANN A power ST ATION P. O. 80 x 402 MINE R A L, Vf RGINI A 23117 February 11, 1981 Mr. James P. O'Reilly, Director Serial No.

N-81-031 Office of Inspection and Enforcement N0/RCS:mbf U. S. Nuclear Regulatory Commission Docket No. 50-339 Region II 101 Marietta Street, Suite 3100 License Nu.

NPF-7 Atlanta, Georgia 30303

Dear Mr. O'Reilly:

Pursuant to North Anna Power Station Technical Specifications, the Virginia Electric and Power Company hereby submits the following Licensee Event Report for North Anna Unit No. 2.

Report No.

Applicable Technical Specifications LER 81-010/03L-0 T.S. 6.9.1.9.b This report has been reviewed by the Station Nuclear Safety and Operating Committee and will be placed on the agenda for the next meeting of the System Nuclear Safety and Operating Committee.

Very Truly yours,

3 hV b W. R. Cartwright Station Manager Enclosures (3 copies) r v.

P cc:

Mr. Victor Stello, Director (30 copies) 2~ -

Office of Inspection and Enforcement Mr. Norman M. Haller, Director (3 copies)

Office of Management and Program Analysis r-L-

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', 1 810'180525 g

2

Virginia Electric and Power Company North Anna Power Station, Unit #2

Attachment:

Page 1 of 1 Docket No. 50-339 Report No. LER 81-010/03L-0

Description of Event

On January 13, 1981, with Unit 2 at 100 percent power, an overspeed trip of the turbine driven auxiliary feedwater pump occurred during surveillance testing. This event is reportable pursuant to T.S. 6.9.1.9.b.

Probable Consequences of Occurrence Two redundant full size motor driven auxiliary feedwater pumps were operable. The turbine-driven auxiliary feedwater pump was tested and returned to operable status with 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> of the event. The action statement of the LCO was met.

The public health and safety were not affected.

Cause of Event

j The turbine governor failed to control the turbine speed properly.

The cause of the governor failure was not determined.

Immediate Corrective Action

The turbine trip valve was disassembled, checked, and reassembled.

The turbine throttle valve, which is controlled by the governor, was checked for proper operation and the turbine governor was replaced. The turbine driven auxiliary feedwater pump was returned to operable status after being tested in accordance with T.S. and IWP requirements.

Scheduled Corrective Action No scheduled corrective actions are required.

Actions Taken to Prevent Recurrence Since August 1980, the Unit 1 turbine driven auxiliary feedwater pump has had three overspeed trips unexpectedly and Unit 2 turbine driven auxiliary feedwater pump has had two unexpected overspeed trips.

Although turbine governor problems were responsible for all five events, i

l the specific problems found do not appear to be closely related. An investigation is being conducted to determine actions which should be taken to prevent recurrance, if any.

Generic Implications No generic implications have been identified.

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