ML20086S491

AO-S2-74-07:on 740810,summator TM-2-4126 Found Drifted Allowing Overpower Setpoint to Be Approx 5% High.Cause Not Determined.Investigation Continuing & Complete Rept Will Be Submitted When Investigation Complete

ML20086S491
Person / Time
Site:	Surry
Issue date:	08/20/1974
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-S2-74-07, AO-S2-74-7, NUDOCS 8403020373
Download: ML20086S491 (1)

Text

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O O VinoixiA E x.1:c rusc An n l'ows:n Coot t'ANY Itsen> oun.vt HOINI A Ofl0 Un August 20, 1974 Mr. Norman C. Moseley, Director Serial No. 248 Directorate of Regulatory Operations P0&M/JTB:clw United States Atomic Energy Commission Region II - Suite 818 Docket No. 50-281 230 Peachtree Street, Northwest License No. DPR-37 Atlanta, Georgia 30303

Dear Mr. Moseley:

Pursuant to Sitrry Power Station Technical Specification 6.6.B.1, the Virginia Electric and Power Company hereby notifies you of an abnorcal occurrence which occurred on August 10, 1974.

With Unit No. 2 operating at 100 per cent of rated power, Periodic Tese 2.1 " Reactor Coolant Temperature Protection Instrumentation" was being performed.

At approximately 1030 hours0.0119 days <br />0.286 hours <br />0.0017 weeks <br />3.91915e-4 months <br />, it una found that surmnator TM-2-4126 had drif ted allowing the overpower AT set point to be approximately five per cent high.

Af ter its removal, the sunmator could not be made to drif t or operate incorrectly in any manner under very exte' naive bench testing. At this time, the cause of the suc=tator f ailure has not been determined. The investigation is continuing and a complete report, designated as A0-S2-74-07, will be submitted I when the investigation is complete.

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

Very truly yours, w' h,, 27 ,. ,

.] ' e '[

l. .;4J/6 '.'

C. M. Stallings Vice President-Power Supply and Production Operations cc: Mr. K. R. Coller, Assistant Director for Operating Reactors 8403020373 741216 PDR ADOCK 05000200 PDR 8

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