ML20086S506

AO-S2-74-06:on 740803,three Main Steam Line Trip Valves Failed to Operate.Caused by Binding in Rockshaft Bushings. Bushings Reamed & Valves Reassembled

ML20086S506
Person / Time
Site:	Surry
Issue date:	08/13/1974
From:	Stallings C VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:	Moseley N NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML20086S438	List: ML20086S437 ML20086S491 ML20086S506
References
AO-S2-74-06, AO-S2-74-6, NUDOCS 8403020376
Download: ML20086S506 (1)

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haiCQ\/[9Q Va notxz A Er.ncrate Ann Powen COMI*ANY , Ahh}hJgp Rxcnnown.Vinoix A 2 0 c 01 -

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August 13, 1974 u, yy g '

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Mr. Norman C. Meeclay, Director Serial No. 236 Directorate of Regulatory Operations P0&M/JTBaclw United States Atoaic Energy Cocaission Region II - Guita 818 Docket No. 50-281 230 Peachtree Strcot, Northwest License No. DPR-37 Atlanta, Georzia 30303

Dear Mr. Moseley:

Pursuant to Surry Power Station Technical Specification 6.6.B.1, the Virginia Elcetric and Power Company hereby notifies you of an abnomal occurrence which occurred on August 3, 1974.

Uith Unit No. 2 operating at 58 per cent of rated power, the three (3) r.ain ocean lino trip valves failed to operate natisfactorily during the performance of the nonthly periodic test. As part of the periodic toot, each valva is stroked approxis tely six (6) degrees to verify freedom of move cut. Initial atto:npts to perform the test on cach of the three (3) valves were not succcccful.

During a cubsequent atte:pt, the "B" trip valve closed and the unit tripped.

Af ter recovering frco the trip and t:anual clocure of the nonreturn valves, "A" trip valve was operated natisfactorily, but "C" still failed to close.

Investigation of the valves indicated appa' rent binding in the rockshaf t bushingo. The bushings were reamed and the valves re-assenbled. Tests conducted following this corrective action verified proper valva operation.

An investigation is presently bsing conducted.to determine the reason for the binding of t.he rockshaf ts. A complete report, designated as A0-S2-74-06, will be subsitted when the investigation is complete.

The purpose of this notification is to satisfy the ten (10) day reporting requirement required by Technical Specification 6.6.B.1.

1 Very truly yours,

- $sUEf l C. M. y Stallings Vice President-Pover Supply and Production Operations (/ 1 cc: Mr. K. R. Coller,' Assistant Directord

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