ML20084J502

Ro:On 721220,during Full Closure Timing Tests,Msiv AO-2-203-1D Closure Time Exceeded Tech Spec Limit.Valve re-timed & New Method of Timing Reviewed

ML20084J502
Person / Time
Site:	Quad Cities
Issue date:	01/03/1973
From:	Stephenson B COMMONWEALTH EDISON CO.
To:	Giambusso A US ATOMIC ENERGY COMMISSION (AEC)
Shared Package
ML20084J493	List: ML20084J490 ML20084J495 ML20084J499 ML20084J502 ML20084J506 ML20084J509
References
BBS-73-2, NUDOCS 8305130329
Download: ML20084J502 (2)

Text

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m Comm ealth Edison

. e Ouad Cit, Jucicar Pow;r Station 0 J g - O P;st Offica Box 216

• ', Cordova, tihnois 61242 Telephono 309/654 2241

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5 UA N s 197 6 J l January 3,1973 C u. r.mte mp- ,

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\ f.[pk. 4 Mr. Angelo Giambusso a Deputy Director of Reactor Projec s l Directorate of Licensing U. S. Atomic Energy Commission Washington, D. C. 20545 Re fe rence : Quad-Cities Nuclear Power Station - Unit 2 Docket No. 50-265; DPR-29, Appendix A i Sections 1.0.A.2, 3.7.D.1, and 6.6.B.s l

Dear Mr. Giambusso:

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. i The purpose of this letter is to inform you of the details relating to an incident in which the closure time for Main Steam Isolation Valve (VSIV) A0-2-203-lD apparen'bly exceeded technical npecification limits. This incident was reported to you by telegram on December 20, 1972.

DESCRIPTION OF INCIDENT On December 20, 1972 at 3: 15 a.m., full closure timing tests were performed on Unit 2 MSIV's 203-1A and 203-1D. The unit was shutdown to locate and repair condenser tube leaks. '

MSIV 1A closed in 4.0 seconds, but MSIV 1D took 51 seconds

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to close.~~The T6dhnical Specifications requ'.re that these valves close in 3 s t 4 5 seconds. The valve was inspected and appeared to be operating normally. The valve timing was adjusted and three successive closure tests were performed l

} and the valve closed in 3.0 seconds each time.

INVESTIGATION I During a two day outage prior to this abnormal occurrence M repairs were made to the position indicating limit switches (10 on MSIV's lA and 1D. This minor maintenance should not have affected the valve times, however, timing tests were performed as a precautionary measure prior to returning the valves to service. The last full closure timing on these valves was conducted on October 6,1972 when valves lA and 1D closed in t 4.2 and 4.4 seconds respectively. _

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' COPY FENT REGION 3 __

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[Ohla 210 pf)

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'Mr. Angelo Giambusso January 3,1973 i

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_ CORRECTIVE' ' ACTION In being is addition to rc-timing the valve, a new method of timing reviewed.

valves is a stop watch The present from method the control used to time isolatior room.

using re cor_d der.is being developed which willA allow modificatim these valves to b

'Ihis will provide us with more accurate crosure times in the future and enable us to spot any trends in closure times by providing a permanent record for analysis y)fd ,h Very truly yours, bq

.Y COMMONWEALTH EDISON COMPANY QUAD-C LEAR POWER STATION '

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B.B.Ste{phenson Superintendent BBS/zm

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